2003 GMC Envoy Owners Manual

vibrations and vehicle bounce.

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Controlling your vehicle is the key to successful off-road driving. One of the best ways to control your vehicle is to control your speed. Here are some things to keep in mind. At higher speeds:

you approach things faster and you have less time to scan the terrain for obstacles. you have less time to react. you have more vehicle bounce when you drive over obstacles. you’ll need more distance for braking, especially since you’re on an unpaved surface.

When you’re driving off-road, bouncing and quick changes in direction can easily throw you out of position. This could cause you to lose control and crash. So, whether you’re driving on or off the road, you and your passengers should wear safety belts.

Scanning the Terrain Off-road driving can take you over many different kinds of terrain. You need to be familiar with the terrain and its many different features. Here are some things to consider.

Surface Conditions: Off-roading can take you over hard-packed dirt, gravel, rocks, grass, sand, mud, snow or ice. Each of these surfaces affects the steering, acceleration and braking of your vehicle in different ways. Depending upon the kind of surface you are on, you may experience slipping, sliding, wheel spinning, delayed acceleration, poor traction and longer braking distances.

Surface Obstacles: Unseen or hidden obstacles can be hazardous. A rock, log, hole, rut or bump can startle you if you’re not prepared for them. Often these obstacles are hidden by grass, bushes, snow or even the rise and fall of the terrain itself. Here are some things to consider:

Is the path ahead clear? Will the surface texture change abruptly up ahead? Does the travel take you uphill or downhill? (There’s more discussion of these subjects later.) Will you have to stop suddenly or change direction quickly?

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Driving on Off-Road Hills Off-road driving often takes you up, down or across a hill. Driving safely on hills requires good judgment and an understanding of what your vehicle can and can’t do. There are some hills that simply can’t be driven, no matter how well built the vehicle.

Ma - hills are simply too steep for any vehicle. If you drive up them, you will stall. If you drive down them, you can’t control your speed. If you drive across them, you will roll over. You could be seriously injured or killed. If you have any doubt about the steepness, don’t drive the hill.

When you drive over obstacles or rough terrain, keep a firm grip on the steering wheel. Ruts, troughs or other surface features can jerk the wheel out of your hands if you’re not prepared. When you drive over bumps, rocks, or other obstacles, your wheels can leave the ground. If this happens, even with one or two wheels, you can’t control the vehicle as well or at all. Because you will be on an unpaved surface, it’s especially important to avoid sudden acceleration, sudden turns or sudden braking. In a way, off-road driving requires a different kind of alertness from driving on paved roads and highways. There are no road signs, posted speed limits or signal lights. You have to use your own good judgment about what is safe and what isn’t. Drinking and driving can be very dangerous on any road. And this is certainly true for off-road driving. At the very time you need special alertness and driving skills, your reflexes, perceptions and judgment can be affected by even a small amount of alcohol. You could have a serious - or even fatal - accident if you drink and drive or ride with a driver who has been drinking. See Drunken Driving on page 4-2.

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Approaching a Hill When you approach a hill, you need to decide if it’s one of those hills that’s just too steep to climb, descend or cross. Steepness can be hard to judge. On a very small hill, for example, there may be a smooth, constant incline with only a small change in elevation where you can easily see all the way to the top. On a large hill, the incline may get steeper as you near the top, but you may not see this because the crest of the hill is hidden by bushes, grass or shrubs. Here are some other things to consider as you approach a hill.

Is there a constant incline, or does the hill get sharply steeper in places? Is there good traction on the hillside, or will the surface cause tire slipping? Is there a straight path up or down the hill so you won’t have to make turning maneuvers? Are there obstructions on the hill that can block your path (boulders, trees, logs or ruts)? What’s beyond the hill? Is there a cliff, an embankment, a drop-off, a fence? Get out and walk the hill if you don’t know. It’s the smart way to find out. Is the hill simply too rough? Steep hills often have ruts, gullies, troughs and exposed rocks because they are more susceptible to the effects of erosion.

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Driving Uphill Once you decide you can safely drive up the hill, you need to take some special steps.

e Use a low gear and get a firm grip on the steering

wheel. Get a smooth start up the hill and try to maintain your speed. Don’t use more power than you need, because you don’t want your wheels to start spinning or sliding. Try to drive straight up the hill if at all possible. If the path twists and turns, you might want to find another route.

Turning or driving across steep hills can be dangerous. You could lose traction, slide sideways, and possibly roll over. You could be seriously injured or killed. When driving up hills, always try to go straight up.

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Ease up on your speed as you approach the top of Q: the hill. Attach a flag to the vehicle to make you more visible to approaching traffic on trails or hills. Sound the horn as you approach the top of the hill to let opposing traffic know you’re there. Use your headlamps even during the day. They make you more visible to oncoming traffic.

A:

Driving to the top (crest) of a hill at full speed can cause an accident. There could be a drop-off, embankment, cliff, or even another vehicle. You could be seriously killed. As you near the top of a hill, slow down and stay alert.

injured or

What should I do if my vehicle stalls, or is about to stall, and I can’t make it up the hill?

If this happens, there are some things you should do, and there are some things you must not do. First, here’s what you should do: Push the brake pedal to stop the vehicle and keep it from rolling backwards. Also, apply the parking brake. If your engine is still running, shift the transmission to REVERSE (R), release the parking brake, and slowly back down the hill in REVERSE (R). If your engine has stopped running, you’ll need to restart it. With the brake pedal pressed and the parking brake still applied, shift the transmission to PARK (P) and restart the engine. Then, shift to REVERSE (R), release the parking brake, and slowly back down the hill as straight as possible in REVERSE (R). As you are backing down the hill, put your left hand on the steering wheel at the 12 o’clock position. This way, you’ll be able to tell if your wheels are straight and maneuver as you back down. It’s best that you back down the hill with your wheels straight rather than in the left or right direction. Turning the wheel too far to the left or right will increase the possibility of a rollover.

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Here are some things you must not do if you stall, or are about to stall, when going up a hill.

Never attempt to prevent a stall by shifting into NEUTRAL (N) to “rev-up” the engine and regain forward momentum. This won’t work. Your vehicle will roll backwards very quickly and you could go out of control. Instead, apply the regular brake to stop the vehicle. Then apply the parking brake. Shift to REVERSE (R), release the parking brake, and slowly back straight down. Never attempt to turn around if you are about to stall when going up a hill. If the hill is steep enough to stall your vehicle, it’s steep enough to cause you to roll over if you turn around. If you can’t make it up the hill, you must back straight down the hill.

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Q: Suppose, after stalling, I try to back down

the hill and decide I just can’t do it. What should I do?

A: Set the parking brake, put your transmission in

PARK (P) and turn off the engine. Leave the vehicle and go get some help. Exit on the uphill side and stay clear of the path the vehicle would take if it rolled downhill. Do not shift the transfer case to NEUTRAL when you leave the vehicle. Leave it in some gear.

Shifting the transfer case to NEUTRAL can cause your vehicle to roll even if the transmission is in PARK (P). This is because the NEUTRAL position on the transfer case overrides the transmission. You or someone else could be injured. If you are going to leave your vehicle, set the parking brake and shift the transmission to PARK (P). But do not shift the transfer case to NEUTRAL. Leave the transfer case in the 2 Wheel High, 4 High or 4 Low position.

Driving Downhill When off-roading takes you downhill, you’ll want to consider a number of things:

How steep is the downhill? Will I be able to maintain vehicle control? What’s the surface like? Smooth? Rough? Slippery? Hard-packed dirt? Gravel? Are there hidden surface obstacles? Ruts? Logs? Boulders? What’s at the bottom of the hili? Is there a hidden creek bank or even a river bottom with large rocks?

If you decide you can go down a hill safely, then try to keep your vehicle headed straight down, and use a low gear. This way, engine drag can help your brakes and they won’t have to do all the work. Descend slowly, keeping your vehicle under control at all times.

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[King when goi ng down a hill can

cause your brakes to overheat and fade. This could cause loss of control and a serious accident. Apply the brakes lightly when descending a hill and use a low gear to keep vehicle speed under control.

driving down a hill?

Q: Are there some things I should not do when A: Yes! These are important because if you ignore them you could lose control and have a serious accident. When driving downhill, avoid turns that take you across the incline of the hill. A hill that’s not too steep to drive down may be too steep to drive across. You could roll over if you don’t drive straight down. Never go downhill with the transmission in NEUTRAL (N). This is called “free-wheeling.” Your brakes will have to do all the work and could overheat and fade.

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Q: Am I likely to stall when going downhill? A: It’s much more likely to happen going uphill. But if it

happens going downhill, here’s what to do. Stop your vehicle by applying the regular brakes. Apply the parking brake. Shift to PARK (P) and, while still braking, restart the engine. Shift back to a low gear, release the parking brake, and drive straight down. If the engine won’t start, get out and get help.

Driving Across an Incline Sooner or later, an off-road trail will probably go across the incline of a hill. If this happens, you have to decide whether to try to drive across the incline. Here are some things to consider:

A hill that can be driven straight up or down may be too steep to drive across. When you go straight up or down a hill, the length of the wheel base (the distance from the front wheels to the rear wheels)

reduces the likelihood the vehicle will tumble end over end. But when you drive across an incline, the much more narrow track width (the distance between the left and right wheels) may not prevent the vehicle from tilting and rolling over. Also, driving across an incline puts more weight on the downhill wheels. This could cause a downhill slide or a rollover. Surface conditions can be a problem when you drive across a hill. Loose gravel, muddy spots, or even wet grass can cause your tires to slip sideways, downhill. If the vehicle slips sideways, it can hit something that will trip it (a rock, a rut, etc.) and roll over. Hidden obstacles can make the steepness of the incline even worse. If you drive across a rock with the uphill wheels, or if the downhill wheels drop into a rut or depression, your vehicle can tilt even more.

For reasons like these, you need to decide carefully whether to try to drive across an incline. Just because the trail goes across the incline doesn’t mean you have to drive it. The last vehicle to try it might have rolled over.

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Driving across an incline that’s too steep will make your vehicle roll over. You could be seriously injured or killed. If you have any doubt about the steepness of the incline, don’t drive across it. Find another route instead.

Q: What if I’m driving across an incline that’s not too steep, but I hit some loose gravel and start to slide downhill. What should I do? A: If you feel your vehicle starting to slide sideways, turn downhill. This should help straighten out the vehicle and prevent the side slipping. However, a much better way to prevent this is to get out and ”walk the course” so you know what the surface is like before you drive it.

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Stalling on an Incline If your vehicle stalls when you’re crossing an incline, be sure you (and your passengers) get out on the uphill side, even if the door there is harder to open. If you get out on the downhill side and the vehicle starts to roll over, you’ll be right in its path. If you have to walk down the slope, stay out of the path the vehicle will take if it does roll over.

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Getting out on the downhill (low) side of a vehicle stopped across an incline is dangerous. If the vehicle rolls over, you could be crushed or killed. Always get out on the uphill (high) side of the vehicle and stay well clear of the rollover path.

Driving in Mud, Sand, Snow or Ice When you drive in mud, snow or sand, your wheels won’t get good traction. You can’t accelerate as quickly, turning is more difficult, and you’ll need longer braking distances. It’s best to use a low gear when you’re in mud - the deeper the mud, the lower the gear. In really deep mud, the idea is to keep your vehicle moving so you don’t get stuck. When you drive on sand, you’ll sense a change in wheel traction. But it will depend upon how loosely packed the sand is. On loosely packed sand (as on beaches or sand dunes) your tires will tend to sink into the sand. This has an effect on steering, accelerating and braking. Drive at a reduced speed and avoid sharp turns or abrupt maneuvers.

Hard packed snow and ice offer the worst tire traction. On these surfaces, it’s very easy to lose control. On wet ice, for example, the traction is so poor that you will have difficulty accelerating. And if you do get moving, poor steering and difficult braking can cause you to slide out of control.

If the water isn’t too deep, drive slowly through it. At faster speeds, water splashes on your ignition system and your vehicle can stall. Stalling can also occur if you get your tailpipe under water. And, as long as your tailpipe is under water, you’ll never be able to start your engine. When you go through water, remember that when your brakes get wet, it may take you longer to stop.

Driving on frozen lakes, ponds or rivers can be dangerous. Underwater springs, currents under the ice, or sudden thaws can weaken the ice. Your vehicle could fall through the ice and you and your passengers could drown. Drive your vehicle on safe surfaces only.

Driving in Water Heavy rain can mean flash flooding, and flood waters demand extreme caution. Find out how deep the water is before you drive through it. If it’s deep enough to cover your wheel hubs, axles or exhaust pipe, don’t try it - you probably won’t get through. Also, water that deep can damage your axle and other vehicle parts.

Driving through rushing water can be dangerous. Deep water can sweep your vehicle downstream and you and your passengers could drown. If it’s only shallow water, it can still wash away the ground from under your tires, and you could lose traction and roll the vehicle over. Don’t drive through rushing water.

See Driving in Rain and on Wet Roads on page 4-30 for more information on driving through water.

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Driving at Night

After Off-Road Driving Remove any brush or debris that has collected on the underbody, chassis or under the hood. These accumulations can be a fire hazard. After operation in mud or sand, have the brake linings cleaned and checked. These substances can cause glazing and uneven braking. Check the body structure, steering, suspension, wheels, tires and exhaust system for damage. Also, check the fuel lines and cooling system for any leakage. Your vehicle will require more frequent service due to off-road use. Refer to the Maintenance Schedule for additional information.

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Night driving is more dangerous than day driving. One reason is that some drivers are likely to be impaired - by alcohol or drugs, with night vision problems, or by fatigue. Here are some tips on night driving.

Drive defensively. Don't drink and drive.

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Since you can’t see as well, you may need to slow down and keep more space between you and other vehicles.

0 Slow down, especially on higher speed roads. Your headlamps can light up only so much road ahead. In remote areas, watch for animals, If you’re tired, pull off the road in a safe place and rest.

No one can see as well at night as in the daytime. But as we get older these differences increase. A 50-year-old driver may require at least twice as much light to see the same thing at night as a 20-year-old. What you do in the daytime can also affect your night vision. For example, if you spend the day in bright sunshine you are wise to wear sunglasses. Your eyes will have less trouble adjusting to night. But if you’re driving, don’t wear sunglasses at night. They may cut down on glare from headlamps, but they also make a lot of things invisible.

You can be temporarily blinded by approaching headlamps. It can take a second or two, or even several seconds, for your eyes to readjust to the dark. When you are faced with severe glare (as from a driver who doesn’t lower the high beams, or a vehicle with misaimed headlamps), slow down a little. Avoid starina directly into the approaching headlamps. Keep your windshield and all the glass on your vehicle clean - inside and out. Glare at night is made much worse by dirt on the glass. Even the inside of the glass can build up a film caused by dust. Dirty glass makes lights dazzle and flash more than clean glass would, making the pupils of your eyes contract repeatedly. Remember that your headlamps light up far less of a roadway when you are in a turn or curve. Keep your eyes moving; that way, it’s easier to pick out dimly lighted objects. Just as your headlamps should be checked regularly for proper aim, so should your eyes be examined regularly. Some drivers suffer from night blindness - the inability to see in dim light - and aren’t even aware of it.

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Driving in Rain and on Wet Roads

Rain and wet roads can mean driving trouble. On a wet road, you can't stop, accelerate or turn as well because your tire-to-road traction isn't as good as on dry roads. And, if your tires don't have much tread left, you'll get even less traction. It's always wise to go slower and be cautious if rain starts to fall while you are driving. The surface may get wet suddenly when your reflexes are tuned for driving on dry pavement.

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Driving too fast through large water puddles or even going through some car washes can cause problems, too. The water may affect your brakes. Try to avoid puddles. But if you can’t, try to slow down before you hit them.

can cause acL .--. .ts. Th,, won’t Wet br,..es work as well in a quick stop and may cause pulling to one side. You could lose control of the vehicle. After driving through a large puddle of water or a car wash, apply your brake pedal lightly until your brakes work normally.

Hydroplaning Hydroplaning is dangerous. So much water can build up under your tires that they can actually ride on the water. This can happen if the road is wet enough and you’re going fast enough. When your vehicle is hydroplaning, it has little or no contact with the road.

Hydroplaning doesn’t happen often. But it can if your tires do not have much tread or if the pressure in one or more is low. It can happen if a lot of water is standing on the road. If you can see reflections from trees, telephone poles or other vehicles, and raindrops “dimple” the water’s surface, there could be hydroplaning. Hydroplaning usually happens at higher speeds. There just isn’t a hard and fast rule about hydroplaning. The best advice is to slow down when it is raining. Driving Through Deep Standing Water

Notice: If you drive too quickly through deep puddles or standing water, water can come in through your engine’s air intake and badly damage your engine. Never drive through water that is slightly lower than the underbody of your vehicle. If you can’t avoid deep puddles or standing water, drive through them very slowly.

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D%ng Through Flowing Water

Some Other Rainy Weather Tips

Besides slowing down, allow some extra following distance. And be especially careful when you pass another vehicle. Allow yourself more clear room ahead, and be prepared to have your view restricted by road spray. Have good tires with proper tread depth. See Tires on page 5-56.

Flowing or rushing water creates strong forces. If you try to drive through flowing water, as you might at a low water crossing, your vehicle can be carried away. As little as six inches of flowing water can carry away a smaller vehicle. If this happens, you and other vehicle occupants could drown. Don’t ignore police warning signs, and otherwise be very cautious about trying to drive through flowing water.

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City Driving

One of the biggest problems with city streets is the amount of traffic on them. You’ll want to watch out for what the other drivers are doing and pay attention to traffic signals. Here are ways to increase your safety in city driving: e Know the best way to get to where you are going. Get a city map and plan your trip into an unknown part of the city just as you would for a cross-country trip. Try to use the freeways that rim and crisscross most large cities. You’ll save time and energy. See Freeway Driving on page 4-34. Treat a green light as a warning signal. A traffic light is there because the corner is busy enough to need it. When a light turns green, and just before you start to move, check both ways for vehicles that have not cleared the intersection or may be running the red light.

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The most important advice on freeway driving is: Keep up with traffic and keep to the right. Drive at the same speed most of the other drivers are driving. Too-fast or too-slow driving breaks a smooth traffic flow. Treat the left lane on a freeway as a passing lane. At the entrance, there is usually a ramp that leads to the freeway. If you have a clear view of the freeway as you drive along the entrance ramp, you should begin to check traffic. Try to determine where you expect to blend with the flow. Try to merge into the gap at close to the prevailing speed. Switch on your turn signal, check your mirrors and glance over your shoulder as often as necessary. Try to blend smoothly with the traffic flow. Once you are on the freeway, adjust your speed to the posted limit or to the prevailing rate if it’s slower. Stay in the right lane unless you want to pass. Before changing lanes, check your mirrors. Then use your turn signal. Just before you leave the lane, glance quickly over your shoulder to make sure there isn’t another vehicle in your “blind” spot.

Freeway Driving

Mile for mile, freeways (also called thruways, parkways, expressways, turnpikes or superhighways) are the safest of all roads. But they have their own special rules.

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Once you are moving on the freeway, make certain you allow a reasonable following distance. Expect to move slightly slower at night. When you want to leave the freeway, move to the proper lane well in advance. If you miss your exit, do not, under any circumstances, stop and back up. Drive on to the next exit. The exit ramp can be curved, sometimes quite sharply. The exit speed is usually posted. Reduce your speed according to your speedometer, not to your sense of motion. After driving for any distance at higher speeds, you may tend to think you are going slower than you actually are. Before Leaving on a Long Trip Make sure you’re ready. Try to be well rested. If you must start when you’re not fresh - such as after a day’s work - don’t plan to make too many miles that first part of the journey. Wear comfortable clothing and shoes you can easily drive in.

Is your vehicle ready for a long trip? If you keep it serviced and maintained, it’s ready to go. If it needs service, have it done before starting out. Of course, you’ll find experienced and able service experts in dealerships all across North America. They’ll be ready and willing to help if you need it. Here are some things you can check before a trip: Windshield Washer Fluid: Is the reservior full? Are all windows clean inside and outside? Wiper Blades: Are they in good shape? Fuel, Engine Oil, Other Fluids: Have you checked all levels? Lamps: Are they all working? Are the lenses clean? Tires: They are vitally important to a safe, trouble-free trip. Is the tread good enough for long-distance driving? Are the tires all inflated to the recommended pressure? Weather Forecasts: What’s the weather outlook along your route? Should you delay your trip a short time to avoid a major storm system? Maps: Do you have up-to-date maps?

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Highway Hypnosis Is there actually such a condition as “highway hypnosis”? Or is it just plain falling asleep at the whee.l? Call it highway hypnosis, lack of awareness, or whatever. There is something about an easy stretch of road with the same scenery, along with the hum of the tires on the road, the drone of the engine, and the rush of the wind against the vehicle that can make you sleepy. Don’t let it happen to you! If it does, your vehicle can leave the road in less than a second, and you could crash and be injured.

What can you do about highway hypnosis? First, be aware that it can happen. Then here are some tips:

Make sure your vehicle is well ventilated, with a comfortably cool interior. Keep your eyes moving. Scan the road ahead and to the sides. Check your mirrors and your instruments frequently. If you get sleepy, pull off the road into a rest, service or parking area and take a nap, get some exercise, or both. For safety, treat drowsiness on the highway as an emergency.

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Hill and Mountain Roads

Driving on steep hills or mountains is different from driving in flat or rolling terrain. If you drive regularly in steep country, or if you’re planning to visit there, here are some tips that can make your trips safer and more enjoyable.

See Off-Road Driving with Your Four-Wheel-Drive Vehicle on page 4-15 for information about driving off-road. 0 Keep your vehicle in good shape. Check all fluid

levels and also the brakes, tires, cooling system and transmission. These parts can work hard on mountain roads. Know how to go down hills. The most important thing to know is this: let your engine do some of the slowing down. Shift to a lower gear when you go down a steep or long hill.

If you don’t shift down, your brakes could get so hot that they wouldn’t work well. You would then have poor braking or even none going down a hill. You could crash. Shift down to let your engine assist your brakes on a steep downhill slope.

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Coasting downhill in NEUTRAL (N) or with the ignition off is dangerous. Your brakes will have to do all the work of slowing down. They could get so hot that they wouldn’t work well. You would then have poor braking or even none going down a hill. You could crash. Always have your engine running and your vehicle in gear when you go downhill.

0 Know how to go uphill. You may want to shift down to a lower gear. The lower gears help cool your engine and transmission, and you can climb the hill better. Stay in your own lane when driving on two-lane roads in hills or mountains. Don’t swing wide or cut across the center of the road. Drive at speeds that let you stay in your own lane. As you go over the top of a hill, be alert. There could be something in your lane, like a stalled car or an accident. You may see highway signs on mountains that warn of special problems. Examples are long grades, passing or no-passing zones, a falling rocks area or winding roads. Be alert to these and take appropriate action.

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Winter Driving

Here are some tips for winter driving:

Have your vehicle in good shape for winter. You may want to put winter emergency supplies in your vehicle.

Include an ice scraper, a small brush or broom, a supply of windshield washer fluid, a rag, some winter outer clothing, a small shovel, a flashlight, a red cloth and reflective warning triangles. And, if you will be driving under severe conditions, include a small bag of sand, a piece of old carpet or a couple of burlap bags to help provide traction. Be sure you properly secure these items in your vehicle.

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Driving on Snow or Ice Most of the time, those places where your tires meet the road probably have good traction. However, if there is snow or ice between your tires and the road, you can have a very slippery situation. You’ll have a lot less traction or “grip” and will need to be very careful.

it’s

What’s the worst time for this? “Wet ice.” Very cold snow or ice can be slick and hard to drive on. But wet ice can be even more trouble because it may offer the least traction of all. You can get wet ice when about freezing (32°F; OOC) and freezing rain begins to fall. Try to avoid driving on wet ice until salt and sand crews can get there. Whatever the condition - smooth ice, packed, blowing or loose snow - drive with caution. If you have traction assist, keep the system on. It will improve your ability to accelerate when driving on a slippery road. But you can turn the traction system off if your vehicle ever gets stuck in sand, mud, ice or snow. See If You Are Stuck: In Sand, Mud, Ice or Snow on page 4-44. Even though your vehicle has a traction system, you’ll want to slow down and adjust your driving to the road conditions. See Traction Assist System (TAS) on page 4-8. If you don’t have a traction system, accelerate gently. Try not to break the gentle traction. If you accelerate too fast, the drive wheels will spin and polish the surface under the tires even more.

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If You’re Caught in a Blizzard

Your anti-lock brakes improve your vehicle’s stability when you make a hard stop on a slippery road. Even though you have an anti-lock braking system, you’ll want to begin stopping sooner than you would on dry pavement. See Braking on page 4-5.

Allow greater following distance on any slippery road.

0 Watch for slippery spots. The road might be fine

until you hit a spot that’s covered with ice. On an otherwise clear road, ice patches may appear in shaded areas where the sun can’t reach: around clumps of trees, behind buildings or under bridges. Sometimes the surface of a curve or an overpass may remain icy when the surrounding roads are clear. If you see a patch of ice ahead of you, brake before you are on it. Try not to brake while you’re actually on the ice, and avoid sudden steering maneuvers.

If you are stopped by heavy snow, you could be in 2 serious situation. You should probably stay with your vehicle unless you know for sure that you are near help and you can hike through the snow.

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Here are some things to do to summon help and keep yourself and your passengers safe: Turn on your hazard flashers. Tie a red cloth to your vehicle to alert police that you’ve been stopped by the snow. Put on extra clothing or wrap a blanket around you. If you have no blankets or extra clothing, make body insulators from newspapers, burlap bags, rags, floor mats - anything you can wrap around yourself or your clothing to keep warm.

tuck under

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You can run the engine to keep warm, but be careful.

Snow can trap exhaust gases under your vehicle. This can cause deadly CO (carbon monoxide) gas to get inside. CO could overcome you and kill you. You can’t see it or smell it, so you might not know it is in your vehicle. Clear away snow from around the base of your vehicle, especially any that is blocking your exhaust pipe. And check around again from time to time to be sure snow doesn’t collect there. Open a window just a little on the side of the vehicle that’s away from the wind. This will help keep CO out.

Run your engine only as long as you must. This saves fuel. When you run the engine, make it go a little faster than just idle. That is, push the accelerator slightly. This uses less fuel for the heat that you get and it keeps the battery charged. You will need a well-charged battery to restart the vehicle, and possibly for signaling later on with your headlamps. Let the heater run for a while. Then, shut the engine off and close the window almost all the way to preserve the heat. Start the engine again and repeat this only when you feel really uncomfortable from the cold. But do it as little as possible. Preserve the fuel as long as you can. To help keep warm, you can get out of the vehicle and do some fairly vigorous exercises every half hour or so until help comes.

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If You Are Stuck: In Sand, Mud, Ice or Snow In order to free your vehicle when it is stuck, you will need to spin the wheels, but you don’t want to spin your wheels too fast. The method known as “rocking” can help you get out when you’re stuck, but you must use caution.

lr tires spir

t high speed, they

If you let p can explode, and you or others could be injured. And, the transmission or other parts of the vehicle can overheat. That could cause an engine compartment fire or other damage. When you’re stuck, spin the wheels as little as possible. Don’t spin the wheels above 35 mph (55 km/h) as shown on the speedometer.

Notice: Spinning your wheels can destroy parts of your vehicle as well as the tires. If you spin the wheels too fast while shifting your transmission back and forth, you can destroy your transmission. For information about using tire chains on your vehicle, see Tire Chains on page 5-64. Rocking Your Vehicle To Get It Out First, turn your steering wheel left and right. That will clear the area around your front wheels. If you have a four- wheel-drive vehicle, shift into 4HI. Then shift back and forth between REVERSE (R) and a forward gear, spinning the wheels as little as possible. Release the accelerator pedal while you shift, and press lightly on the accelerator pedal when the transmission is in gear. By slowly spinning your wheels in the forward and reverse directions, you will cause a rocking motion that may free your vehicle. If that doesn’t get you out after a few tries, you may need to be towed out. If you do need to be towed out, see Towing Your Vehicle on page 4-45.

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Towing

Towing Your Vehicle Consult your dealer or a professional towing service if you need to have your disabled vehicle towed. See Roadside Assistance Program on page 7-5. If you want to tow your vehicle behind another vehicle for recreational purposes (such as behind a motorhome), see “Recreational Vehicle Towing” following. Recreational Vehicle Towing Recreational vehicle towing means towing your vehicle behind another vehicle - such as behind a motorhome. The recreational vehicle towing” (towing your vehicle with all four wheels on the ground) and “dolly towing” with two wheels on the a device known as a “dolly”).

ground and two wheels up on

towing are known as ”dinghy

two most common types of

(towing your vehicle

With the proper preparation and equipment, many vehicles can be towed in these ways. See “Dinghy Towing” and “Dolly Towing,” following. Here are some important things to consider before you do recreational vehicle towing:

What’s the towing capacity of the towing vehicle? Be sure you read the tow vehicle manufacturer’s recommendations. How far will you tow? Some vehicles have restrictions on how far and how long they can tow. Do you have the proper towing equipment? See your dealer or trailering professional for additional advice and equipment recommendations. Is your vehicle ready to be towed? Just as you would prepare your vehicle for a long trip, you’ll want to make sure your vehicle is prepared to be towed. See Before Leaving on a Long Trip on page 4-35.

4-45

Dinghy Towing When towing your vehicle, turn the ignition off. To prevent your battery from draining while towing, remove the Ignition A and the Ignition B fuses from the engine compartment fuse block. Be sure to reinstall the fuse when you reach your destination. Two-Wheel-Drive Vehicles Two-wheel-drive vehicles should not be towed with all four wheels on the ground. Two-wheel-drive transmissions have no provisions for internal lubrication while being towed. To properly tow these vehicles, they should be placed on a platform trailer. In rare cases when it’s unavoidable that a two-wheel-drive vehicle is to be towed with all four wheels on the ground, the propeller shaft to axle yoke orientation should be marked and the propeller shaft removed following the applicable service manual removal/installation procedure. Dust or dirt can enter the back of the transmission through the opening created by removing the propeller shaft if proper protection is not provided. Also, check the transmission fluid level before driving the truck.

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Four-Wheel-Drive Vehicles

Use the following procedure to tow your vehicle: 1. Firmly set the parking brake. 2. Shift the transmission to PARK (P). 3. Securely attach the vehicle being towed to the tow

vehicle.

4. Shift the transfer case to NEUTRAL (N). See “Four-Wheel Drive” in the Index for the proper procedure to select the NEUTRAL position for your vehicle.

5. Release the parking brake only after the vehicle

being towed is firmly attached to the towing vehicle.

6. Turn the ignition off and remove the key. If the key

is not removed, the battery will drain.

I Shifting a four-wheel-drive vehicle’s transfer

case into NEUTRAL can cause your vehicle to roll even if the transmission is in Park (P). You or others could be injured. Make sure the parking brake is firmly set before you shift the transfer case to NEUTRAL.

Dolly Towing Your vehicle was not designed to be dolly towed. If you need to tow your vehicle, see “Dinghy Towing” earlier in this section.

ng a fou -vheel-drive vehicle’s transfer

case into NEUTRAL can cause your vehicle to roll even if the transmission is in Park (P). You or others could be injured. Make sure the parking brake is firmly set before you shift the transfer case to NEUTRAL.

4-47

Loading Your Vehicle

I I

p%

RIM

COLD TIRE PRESSUR

The Certificationnire label also tells you the maximum weights for the front and rear axles, called Gross Axle Weight Rating (GAWR). To find out the actual loads on your front and rear axles, you need to go to a weigh station and weigh your vehicle. Your dealer can help you with this. Be sure to spread out your load equally on both sides of the centerline. Never exceed the GVWR for your vehicle, or the GAWR for either the front or rear axle. If you do have a heavy load, you should spread it out. Similar appearing vehicles may have different GVWRs and payloads. Please note your vehicle’s CertificationlTire label or consult your dealer for additional details.

FER’S MANUAL FOR ADDITIONAL INFORMATION^

The Certificationnire label is found on the driver’s door edge, above the door latch. The label shows the size of your original tires and the inflation pressures needed to obtain the gross weight capacity of your vehicle. This is called the Gross Vehicle Weight Rating (GVWR). The GVWR includes the weight of the vehicle, all occupants, fuel, cargo and trailer tongue weight, if pulling a trailer.

4-48

Do not load your vehicle any heavier than the GVWR, or either the maximum front or rear GAWR. If you do, parts on your vehicle can break, and it can change the way your vehicle handles. These could cause you to lose control and crash. Also, overloading can shorten the life of your vehicle.

Using heavier suspension components to get added durability might not change your vehicle’s weight ratings. Ask your dealer to help you load your vehicle the right way. Notice: Your warranty does not cover parts or components that fail because of overloading. If you put things inside your vehicle-like suitcases, tools, packages, or anything else-they will go as fast as the vehicle goes. If you have to stop or turn quickly, or if there’s a crash, they’ll keep going.

Things you put inside your vehicle can strike and injure people in a sudden stop or turn, or in a crash.

Put things in the cargo area of your vehicle. Try to spread the weight evenly. Never stack heavier things, like suitcases, inside the vehicle so that some of them are above the tops of the seats. Don’t leave an unsecured child restraint in your vehicle. When you carry something inside the vehicle, secure it whenever you can. Don’t leave a seat folded down unless you need to.

There’s also important loading information for off-road driving in this manual.

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You may hear the compressor operating when you load your vehicle, and periodically as the system adjusts the vehicle to the standard ride height. Load leveling will not function normally with the inflator hose attached to the inflator outlet. Remove the inflator hose from the outlet during loading and unloading. If the vehicle is parked for an extended period of time, some bleed down of the suspension is normal. Upon starting the vehicle, proper height will be achieved.

Electronically Controlled Air Suspension System Your vehicle may be equipped with an electronically controlled air suspension system that automatically keeps your vehicle level as you load and unload. The system includes a compressor, two height sensors and two air springs supporting the rear axle. The system also has an internal clock to prevent overheating. If the system overheats, all leveling function stops until the system cools down. During this time, the indicator light on the air inflator system will be flashing. The ignition has to be on for the system to inflate, in order to raise the vehicle to the standard ride height after loading. The system can lower the vehicle to the standard ride height after unloading with the ignition on and also for up to 30 minutes after the ignition has been turned off.

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Overload Protection The air suspension system is equipped with overload protection. Overload protection is designed to protect the air suspension system, and it is an indicator to the driver that the vehicle is overloaded. When the overload protection mode is on, it will not allow damage to the air compressor. However, do not overload the vehicle. See Loading Your Vehicle on page 4-48. If the suspension remains at a low height, the rear axle load has exceeded GAWR (Gross Axle Weight Rating). When the overload protection mode is activated, the compressor operates for about 30 seconds to one minute without raising the vehicle depending on the amount of overload. This will continue each time the ignition is turned on until the rear axle load is reduced below GAWR.

for

Indicator Light The indicator light on the inflator switch in the rear passenger compartment also serves as an indicator internal system error. If the indicator light is flashing without the load leveling function or the inflator beins active, turn off the ignition. The next day turn on the ignition and check the indicator light. The vehicle can be driven with the light flashing, but if it is you should have the vehicle serviced as soon as possible. Adding a Snow Plow or Similar Equipment Your vehicle was neither designed nor intended for a snow plow. Notice: Adding a snow plow or similar equipment to your vehicle can damage it, and the repairs wouldn’t be covered by warranty. Do not install a snow plow or similar equipment on your vehicle.

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To identify the trailering capacity of your vehicle, you should read the information in ”Weight of the Trailer” that appears later in this section. Trailering is different than just driving your vehicle by itself. Trailering means changes in handling, durability and fuel economy. Successful, safe trailering takes correct equipment, and it has to be used properly. That’s the reason for this part. In it are many time-tested, important trailering tips and safety rules. Many of these are important for your safety and that of your passengers. So please read this section carefully before you pull a trailer.

Towing a Trailer

If you don’t use the correct eql , ment and drive properly, you can lose control when you pull a trailer. For example, if the trailer is too heavy, the brakes may not work well -- or even at all. You and your passengers could be seriously injured. Pull a trailer only if you have followed all the steps in this section. Ask your dealer for advice and information about towing a trailer with your vehicle.

Notice: Pulling a trailer improperly can damage your vehicle and result in costly repairs not covered by your warranty. To pull a trailer correctly, follow the advice in this part, and see your dealer for important information about towing a trailer with your vehicle. Additional rear axle maintenance is required for a vehicle used to tow a trailer. See “Scheduled Maintenance Services” in the Index.

4-52

With an automatic transmission, you can tow in DRIVE (D). You may want to shift the transmission to THIRD (3) or, if necessary, a lower gear selection if the transmission shifts too often e.g., under heavy loads and/or hilly conditions.

Three important considerations have to do with weight:

the weight of the trailer, the weight of the trailer tongue and the weight on your vehicle’s tires.

If You Do Decide To Pull A Trailer If you do, here are some important points:

There are many different laws, including speed limit restrictions, having to do with trailering. Make sure your rig will be legal, not only where you live but also where you’ll be driving. A good source for this information can be state or provincial police. 0 Consider using a sway control if your trailer will weigh 4,000 Ibs. (1 816 kg) or less. You should always use a sway control if your trailer will weigh more than 4,000 Ibs. (1 816 kg). You can ask a hitch dealer about sway controls.

0 Don’t tow a trailer at all during the first 500 miles (800 km) your new vehicle is driven. Your engine, axle or other parts could be damaged. Then, during the first 500 miles (800 km) that you tow a trailer, don’t drive over 50 mph (80 km/h) and don’t make starts at full throttle. This helps your engine and other parts of your vehicle wear in at the heavier loads.

4-53

Weight of the Trailer How heavy can a trailer safely be? It depends on how you plan to use your rig. For example, speed, altitude, road grades, outside temperature and how much your vehicle is used to pull a trailer are all important. And, it can also depend on any special equipment that you have on your vehicle. Look in the following chart to find the maximum trailer weight for your vehicle.

2WD Envoy (L6 Engine)

10,500 Ibs (4 762 kg)

4WD Envoy (L6 Engine)

2WD Envoy XL (L6 Engine)

4-54

10,000 Ibs. (4 535 kg)

4WD Envoy XL (L6 Engine)

2WD Envoy XL (V8 Engine)

4WD Envoy XL (V8 Engine)

*The Gross Combination Weight Rating (GCWR) is the total allowable weight of the completely loaded vehicle and trailer including any passengers, cargo, equipment and conversion. The GCWR for your vehicle should not be exceeded.

You can ask your dealer for our trailering information or advice, or you can write us at the address listed in your Warranty and Owner Assistance Information Booklet.

In Canada, write to: General Motors of Canada Limited Customer Communication Centre, 163-005 1908 Colonel Sam Drive Oshawa, Ontario L1 H 8P7

4-55

Weight of the Trailer Tongue The tongue load (A) of any trailer is an important weight to measure because it affects the total or gross weight of your vehicle. The Gross Vehicle Weight (GVW) includes the curb weight of the vehicle, any cargo you may carry in it, and the people who will be riding in the vehicle. And if you will tow a trailer, you must add the tongue load to the GVW because your vehicle will be carrying that weight, too. See Loading Your Vehicle on page 4-48 for more information about your vehicle’s maximum load capacity.

If you’re using a weight-carrying or a weight-distributing hitch, the trailer tongue weight (A) should be 10 percent to 15 percent of the total loaded trailer weight (B). Do not exceed the maximum allowable tongue weight for your vehicle. After you’ve loaded your trailer, weigh the trailer and then the tongue, separately, to see if the weights are proper. If they aren’t, you may be able to get them right simply by moving some items around in the trailer. Total Weight on Your Vehicle’s Tires Be sure your vehicle’s tires are inflated to the upper limit for cold tires. You’ll find these numbers on the Certification label at the rear edge of the driver’s door or see ”Tire Loading”. Then be sure you don’t go over the GVW limit for your vehicle, including the weight of the trailer tongue.

4-56

Hitches It’s important to have the correct hitch equipment. Crosswinds, large trucks going by and rough roads are a few reasons why you’ll need the right hitch. Here are some rules to follow:

If you’ll be pulling a trailer that, when loaded, will weigh more than 4,000 Ibs. (1 816 kg), be sure to use a properly mounted, weight-distributing hitch and sway control of the proper size. This equipment is very important for proper vehicle loading and good handling when you’re driving. Will you have to make any holes in the body of your vehicle when you install a trailer hitch? If you do, then be sure to seal the holes later when you remove the hitch. If you don’t seal them, deadly carbon monoxide (CO) from your exhaust can get into your vehicle. See ”Carbon Monoxide”. Dirt and water can, too.

Safety Chains You should always attach chains between your vehicle and your trailer. Cross the safety chains under the tongue of the trailer to help prevent the tongue from contacting the road if it becomes separated from the hitch. Instructions about safety chains may be provided by the hitch manufacturer or by the trailer manufacturer.

Follow the manufacturer’s recommendation for attaching safety chains and do not attach them to the bumper. Always leave just enough slack so you can turn with your rig. Never allow safety chains to drag on the ground. Trailer Brakes If your trailer weighs more than 1,500 Ibs. (680 kg) loaded, then it needs its own brakes - and they must be adequate. Be sure to read and follow the instructions for the trailer brakes so you’ll be able to install, adjust and maintain them properly. Your trailer’s brake system can tap into the vehicle’s hydraulic brake system only if:

The trailer parts can withstand 3,000 psi (20 650 kPa) of pressure.

0 The trailer’s brake system will use less than

0.02 cubic inch (0.3 cc) of fluid from your vehicle’s master cylinder. Otherwise, both braking systems won’t work well. You could even lose your brakes. If everything checks out this far, then make the brake fluid tap at the port on the master cylinder that sends fluid to the rear brakes. But don’t use copper tubing for this. If you do, it will bend and finally break off. Use steel brake tubing.

4-57

rowing a trailer requires a certain amount of experience. Before setting out for the open road, you’ll want to get to know your rig. Acquaint yourself with the feel of handling and braking with the added weight of the trailer. And always keep in mind that the vehicle you are driving is now a good deal longer and not nearly as responsive as your vehicle is by itself. Before you start, check the trailer hitch and platform (and attachments), safety chains, electrical connector, lamps, tires and mirror adjustment. If the trailer has electric brakes, start your vehicle and trailer moving and then apply the trailer brake controller by hand to be sure the brakes are working. This lets you check your electrical connection at the same time. During your trip, check occasionally to be sure that the load is secure, and that the lamps and any trailer brakes are still working.

D 4 n g with a Trailer

If you have a rear-most window open and you pull a trailer with your vehicle, carbon monoxide (CO) could come into your vehicle. You can’t see or smell CO. It can cause unconsciousness or death. See “Engine Exhaust” in the Index. To maximize your safety when towing a trailer:

Have your exhaust system inspected for leaks, and make necessary repairs before starting on your trip. Keep the rear-most windows closed. If exhaust does come into your vehicle through a window in the rear or another opening, drive with your front, main heating or cooling system on and with the fan any speed. This will bring fresh, outside air into your vehicle. Do not use the climate control setting for maximum air because it only recirculates the air inside your vehicle. See “Climate Controls” in the Index.

on

4-58

Following Distance Stay at least twice as far behind the vehicle ahead as you would when driving your vehicle without a trailer. This can help you avoid situations that require heavy braking and sudden turns. Passing You’ll need more passing distance up ahead when you’re towing a trailer. And, because you’re a good deal longer, you’ll need to go much farther beyond the passed vehicle before you can return to your lane. Backing Up Hold the bottom of the steering wheel with one hand. Then, to move the trailer to the left, just move that hand to the left. To move the trailer to the right, move your hand to the right. Always back up slowly and, if possible, have someone guide you.

Making Turns Notice: Making very sharp turns while trailering could cause the trailer to come in contact with the vehicle. Your vehicle could be damaged. Avoid making very sharp turns while trailering. When you’re turning with a trailer, make wider turns than normal. Do this so your trailer won’t strike soft shoulders, curbs, road signs, trees or other objects. Avoid jerky or sudden maneuvers. Signal well in advance. Turn Signals When Towing a Trailer The arrows on your instrument panel will flash whenever you signal a turn or lane change. Properly hooked up, the trailer lamps will also flash, telling other drivers you’re about to turn, change lanes or stop. When towing a trailer, the arrows on your instrument panel will flash for turns even if the bulbs on the trailer are burned out. Thus, you may think drivers behind you are seeing your signal when they are not. It’s important to check occasionally to be sure the trailer bulbs are still working.

4-59

Driving On Grades

Pa-';ing -- '4ills

Reduce speed and shift to a lower gear before you start down a long or steep downgrade. If you don't shift down, you might have to use your brakes so much that they would get hot and no longer work well. You can tow in DRIVE (D). You may want to shift the transmission to THIRD (3) or a lower gear, under heavy loads or hilly conditions. When towing at high altitude on steep uphill grades, consider the following: Engine coolant will boil at a lower temperature than at normal altitudes. If you turn your engine off immediately after towing at high altitude on steep uphill grades, your vehicle may show signs similar to engine overheating. To avoid this, let the engine run while parked (preferably on level ground) with the automatic transmission in PARK (P) for a few minutes before turning the engine off. If you do get the overheat warning, see Engine Overheating on page 5-27.

4-60

.lot pa your vehicle,

You real shoul- trailer attached, on a hill. If something goes wrong, your rig could start to move. People can be injured, and both your vehicle and the trailer can be damaged.

_._ a

But if you ever have to park your rig on a hill, here's how to do it: 1. Apply your regular brakes, but don't shift into

PARK (P) yet. When parking uphill, turn your wheels away from the curb. When parking downhill, turn your wheels into the curb.

2. Have someone place chocks under the trailer

wheels.

3. When the wheel chocks are in place, release the regular brakes until the chocks absorb the load.

4. Reapply the regular brakes. Then apply your

parking brake, and then shift into PARK (P).

5. Release the regular brakes.

It can be dangerous to get out of your vehicle if the shift lever is not fully in PARK (P) with the parking brake firmly set. Your vehicie can roll. If you have left the engine running, the vehicle can move suddenly. You or others could be injured. To be sure your vehicle won’t move, even when you’re on fairly level ground, use the steps that follow. Always put the shift lever fully in PARK (P) with the parking brake firmly set. If the transfer case on four-wheel drive vehicles is in NEUTRAL, your vehicle will be free to roll, even if your shift lever is in PARK (P). So, be sure the transfer case is in a drive gear -- not in NEUTRAL. See “Four-wheel Drive (Automatic Transfer Case)” in the Index.

When You Are Ready to Leave After Parking on a Hill 1. Apply your regular brakes and hold the pedal down

while you: * start your engine, 0 shift into a gear, and * release the parking brake.

2. Let up on the brake pedal. 3. Drive slowly until the trailer is clear of the chocks. 4. Stop and have someone pick up and store the

chocks.

Maintenance When Trailer Towing Your vehicle will need service more often when you’re pulling a trailer. See the Maintenance Schedule for more on this. Things that are especially important in trailer operation are automatic transmission fluid (don’t overfill), engine oil, axle lubricant, belt(s), cooling system and brake system. Each of these is covered in this manual, and the Index will help you find them quickly. If you’re trailering, it’s a good idea to review these sections before you start your trip. Check periodically to see that all hitch nuts and bolts are tight.

4-6 1

Yellow: Left Stopnurn Signal Dark Green: Right Stopllurn Signal Brown: Running Lamps White: Ground Light Green: Back-up Lamps Red: Battery Feed Dark Blue: Electric Brakes

If you need to tow a light-duty trailer with a standard four-way round pin connector, an adapter connector is available from your dealer. Your vehicle may also be equipped with wiring for an electric trailer brake controller. These wires are located inside the vehicle on the driver’s side under the instrument panel. These wires should be connected to an electric trailer brake controller by your dealer or a qualified service center.

Trailer Wiring Harness

Your vehicle may be equipped with the seven-wire trailer towing harness. This harness has a seven-pin universal heavy-duty trailer connector that is attached to a bracket on the hitch platform. The seven-wire harness contains the following trailer circuits:

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Section 5 Service and Appearance Care

Your Vehicle

Service ............................................................ 5.3 Doing Your Own Service Work ......................... 5-4 Adding Equipment to the Outside of

............. .....

.............................................. 5.4 Fuel ................................................................ 5.5 .................... 5.5 Gasoline Octane .................... 5.5 Gasoline Specifications California Fuel ............................................... 5.6 Additives ....................................................... 5.6 Fuels in Foreign Countries ............................... 5.7 Filling Your Tank ............................................ 5-7 Filling a Portable Fuel Container ....................... 5-9 Checking Things Under the Hood .................... 5.10 Hood Release .............................................. 5.10 Engine Compartment Overview ....................... 5.12 Engine Oil ................................................... 5.15 Engine Air Cleaner/Filter ............................... 5-20 Automatic Transmission Fluid ........................ 5.21 Engine Coolant ............................................. 5.24 .................................. 5.26 Radiator Pressure Cap Engine Overheating ....................................... 5.27 Cooling System ............................................ 5.29 Engine Fan Noise ......................................... 5.35 Power Steering Fluid ..................................... 5.36 Windshield Washer Fluid ...... , .................. 5.37

Brakes ........................................................ 5.38 Battery .................................................... 5.41 Jump Starting ............................ ........ 5-42 Rear Axle ...................................................... 5-48 Four-wheel Drive ............................................ 5-49 Bulb Replacement .......................................... 5-51 Halogen Bulbs .............................................. 5-51 Headlamps .................................................. 5-51 Front Turn Signal and Sidemarker Lamps ........ 5-51 Taillamps and Turn Signal Lamps ................... 5-51 Replacement Bulbs ....................................... 5-52 Windshield Wiper Blade Replacement .............. 5-53 Tires .............................................................. 5-56 Inflation -- Tire Pressure ................................ 5-57 Tire Inspection and Rotation ........................... 5-58 When It Is Time for New Tires ....................... 5-59 Buying New Tires ......................................... 5-60 Uniform Tire Quality Grading .......................... 5-61 Wheel Alignment and Tire Balance .................. 5-62 Wheel Replacement ...................................... 5-62 Tire Chains ................................................. 5-64 ............ 5-64 Accessory Inflator . . If a Tire Goes Flat .................................... 5-66 Changing a Flat Tire ..................................... 5-66

5- 1

Section 5

Service and Appearance Care

Appearance Care ............................................ 5.82 Cleaning the Inside of Your Vehicle ................. 5-82 Care of Safety Belts ...................................... 5.85 Weatherstrips ............................................... 5.85 Cleaning the Outside of Your Vehicle .............. 5-85 Sheet Metal Damage ..................................... 5.87 Finish Damage ............................................. 5.88 Underbody Maintenance ................................ 5-88 Chemical Paint Spotting ................................. 5.88 GM Vehicle Care/Appearance Materials ........... 5.88 Vehicle Identification ..................................... 5-90

Vehicle Identification Number (VIN) ................. 5.90 Service Parts Identification Label ..................... 5.90 Electrical System ............................................ 5.91 Add-on Electrical Equipment .......................... 5.91 Headlamps .................................................. 5-91 Windshield Wiper Fuses ................................ 5.91 ....... 5-92 Power Windows and Other Power Options Fuses and Circuit Breakers ........................... 5-92 Capacities and Specifications ........................ 5.104 Normal Maintenance Replacement Parts ......... 5.106

5-2

Service Your dealer knows your vehicle best and wants you to be happy with it. We hope you’ll go to your dealer for all your service needs. You’ii get genuine GM parts and GM-trained and supported service people.

We hope you’ll want to keep your GM vehicle all GM. Genuine GM parts have one of these marks:

5-3

Doing Your Own Service Work If you want to do some of your own service work, you’ll want to use the proper service manual. It tells you much more about how to service your vehicle than this manual can. To order the proper service manual, see Service Publications Ordering Information on page 7- 10. Your vehicle has an air bag system. Before attempting to do your own service work, see Servicing Your Air Bag-Equipped Vehicle on page 1-59. You should keep a record with all parts receipts and list the mileage and the date of any service work you perform. See Part E: Maintenance Record on page 6-19.

5-4

u can be in-

’ed and your veh e could be damaged if you try to do service work on a vehicle without knowing enough about it.

Be sure you have sufficient knowledge, experience, the proper replacement parts and tools before you attempt any vehicle maintenance task. Be sure to use the proper nuts, bolts and other fasteners. “English” and “metric” fasteners can be easily confused. If you use the wrong fasteners, parts can later break or fall off. You could be hurt.

Adding Equipment to the Outside of Your Vehicle Things you might add to the outside of your vehicle can affect the airflow around it. This may cause wind noise and affect windshield washer performance. Check with your dealer before adding equipment to the outside of your vehicle.

Fuel Use of the recommended fuel is an important part of the proper maintenance of your vehicle. Gasoline Octane Use regular unleaded gasoline with a posted octane of 87 or higher. If the octane is less than 87, you may get a heavy knocking noise when you drive. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. Otherwise, you might damage your engine. A little pinging noise when you accelerate or drive uphill is considered normal. This does not indicate a problem exists or that a higher-octane fuel is necessary. If you are using 87 octane or higher-octane fuel and hear heavy knocking, your engine needs service.

Gasoline Specifications

It is recommended that gasoline meet specifications which were developed by the American Automobile Manufacturers Association and endorsed by the Canadian Vehicle Manufacturers Association for better vehicle performance and engine protection. Gasoline meeting these specifications could provide improved driveability and emission control system performance compared to other gasoline.

In Canada, look for the "Auto Makers' Choice" label on the pump.

Canada Only

5-5

General Motors recommends that you use these gasolines, particularly if they comply with the specifications described earlier.

Notices Your vehicle was not designed for fuel that contains methanol. Don’t use fuel containing methanol. It can corrode metal parts in your fuel system and also damage the plastic and rubber parts. That damage wouldn’t be covered under your warranty. Some gasolines that are not reformulated for low emissions may contain an octane-enhancing additive called methylcyclopentadienyl manganese tricarbonyl (MMT); ask the attendant where you buy gasoline whether the fuel contains MMT. General Motors does not recommend the use of such gasolines. Fuels containing MMT can reduce the life of spark plugs and the performance of the emission control system may be affected. The malfunction indicator lamp may turn on. If this occurs, return to your authorized GM dealer for service.

California Fuel If your vehicle is certified to meet California Emission Standards (see the underhood emission control label), it is designed to operate on fuels that meet California specifications. If this fuel is not available in states adopting California emissions standards, your vehicle will operate satisfactorily on fuels meeting federal specifications, but emission control system performance may be affected. The malfunction indicator lamp may turn on (see Malfunction Indicator Lamp on page 3-41) and your vehicle may fail a smog-check test. If this occurs, return to your authorized GM dealer for diagnosis. If it is determined that the condition is caused by the type of fuel used, repairs may not be covered by your warranty. Additives To provide cleaner air, all gasolines in the United States are now required to contain additives that will help prevent engine and fuel system deposits from forming, allowing your emission control system to work properly. You should not have to add anything to your fuel. Gasolines containing oxygenates, such as ethers and ethanol, and reformulated gasolines may be available in your area to contribute to clean air.

5-6

Fuels in Foreign Countries If you plan on driving in another country outside the United States or Canada, the proper fuel may be hard to find. Never use leaded gasoline or any other fuel not recommended in the previous text on fuel. Costly repairs caused by use of improper fuel wouldn’t be covered by your warranty. To check the fuel availability, ask an auto club, or contact a major oil company that does business in the country where you’ll be driving. Filling Your Tank

Fuel vapor is highly flammable. It burns violently, and that can cause very bad injuries. Don’t smoke if you’re near fuel or refueling your vehicle. Keep sparks, flames and smoking materials away from fuel.

The fuel cap is located behind a hinged door on the driver’s side of your vehicle.

5-7

I

son ou get fuel on yourself and then

’g

ignites it, you could be badly burned. Fuel can spray out on you if you open the fuel cap too quickly. This spray can happen if your tank is nearly full, and is more likely in hot weather. Open the fuel cap slowly and wait for any “hiss” noise to stop. Then unscrew the cap all the

way.

While refueling, hang the fuel cap by the tether using the hook located on the inside of the filler door. To remove the fuel cap, turn it slowly to the left (counterclockwise). The fuel cap has a spring in it. If you let go of the cap too soon, it will spring back to the right.

Be careful not to spill fuel. Clean fuel from painted surfaces as soon as possible. See Cleaning the Outside of Your Vehicle on page 5-85. When filling the tank do not overfill by squeezing in much more fuel after the pump shuts off.

5-8

When you put the fuel cap back on, turn it to the right (clockwise) until you hear a clicking sound. Make sure you fully install the cap. The diagnostic system can determine if the fuel cap has been left off or improperly installed. This would allow fuel to evaporate into the atmosphere. See Malfunction lndicator Lamp on page 3-4 1. Notice: If you need a new fuel cap, be sure to get the right type. Your dealer can get one for you. the wrong type, it may not cause your malfunction indicator lamp to light and may damage your fuel tank and emissions system. See “Malfunction lndicator Lamp” in the Index.

fit properly. This may

If you get

Filling a Portable Fuel Container

ile it is in Never fill a portable fuel container I.... your vehicle. Static electricity discharge from the container can ignite the gasoline vapor. You can be badly burned and your vehicle damaged if this occurs. To help avoid injury to you and others:

0 Dispense gasoline only into approved

containers. Do not fill a container while it is inside a vehicle, in a vehicle’s trunk, pickup bed or on any surface other than the ground. Bring the fill nozzle in contact with the inside of the fill opening before operating the nozzle. Contact should be maintained until the filling is complete. Don’t smoke while pumping gasoline.

5-9

Checking Things Under the Hood

Hood Release

To open the hood, first pull the handle located inside the vehicle on the lower driver’s side of the instrument panel.

Things that burn can get on hot engine parts and start a fire. These include liquids like fuel, oil, coolant, brake fluid, windshield washer and other fluids, and plastic or rubber. You or others could be burned. Be careful not to drop or spill things that will burn onto a hot engine.

5-1 0

2. Then go to the front of the vehicle and release the

secondary hood release.

3. Lift the hood; release the hood prop from its retainer and put the hood prop into the slot in the hood.

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A. Coolant Recovery Tank B. Engine Air CleanedFilter C. Windshield Washer Fluid Reservoir D. Engine Air Cleaner/Filter Indicator (If Equipped) E. Power Steering Fluid Reservoir F. Automatic Transmission Dipstick G. Engine Oil Dipstick

H. Radiator Pressure Cap I. Engine Oil Fill Cap J. Remote Negative (-) Terminal Marked “GND” K. Brake Master Cyiinder L. Battery M. Engine Compartment Fuse Block

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When you open the hood on the V8 engine, you’ll see the following:

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Coolant Recovery Tank Engine Air Cleaner/Filter Windshield Washer Fluid Reservoir Engine Oil Dipstick Automatic Transmission Dipstick Engine Oil Fill Cap Radiator Pressure Cap Remote Negative (-) Terminal Marked “GND” Power Steering Fluid Reservoir Brake Master Cylinder Engine Compartment Fuse Block Battery

A. B. C. D. E. F. G. H. I. J. K. L. Before closing the hood, be sure all filler caps are on properly. Then lift the hood to relieve pressure on the hood prop. Remove the hood prop from its slot in the hood and return the prop to its retainer. Then pull the hood down when dropped from 6 to 8 inches (15 to 20 cm) without pressing on the hood.

firmly to close. It will latch

Engine Oil You should check your engine oil level regularly; this is an added reminder. Checking Engine Oil It’s a good idea to check your engine oil every time you get fuel. In order to get an accurate reading, the oil must be warm and the vehicle must be on level ground.

The engine oil dipstick handle is a yellow ring located in the engine compartment toward the passenger’s side of the vehicle. See Engine Compartment Overview page 5- 72 for more information on location.

on

Turn off the engine and give the oil several minutes to drain back into the oil pan. If you don’t, the oil dipstick might not show the actual level. Pull out the dipstick and clean it with a paper towel or cloth, then push it back in all the way. Remove it again, keeping the tip down, and check the level.

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V8 Engine

SAE 5W-30

The engine oil fill cap is located in the engine compartment toward the passenger’s side of the vehicle. See Engine Compartment Overview on page 5-72 for more information on location.

When to Add Engine.Oil If the oil is at or below the F mark for the L6 engine or the cross-hatched area at the tip of the dipstick for the V8 engine, then you’ll need to add at least one quart of oil.

Be sure to fill it enough to put the level somewhere in the proper operating range. Push the dipstick all the way back in when you’re through.

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What Kind of Engine Oil to Use Oils recommended for your vehicle can be identified by looking for the starburst symbol. This symbol indicates that the oil has been certified by the American Petroleum Institute (API). Do not use any oil which does not carry this starburst symbol.

If you choose to perform the engine oil change service yourself, be sure the oil you use has the starburst symbol on the front of the oil container. If you have your oil changed for you, be sure the oil put into your engine is American Petroleum Institute certified for gasoline engines.

You should also use the proper viscosity oil for your vehicle, as shown in the viscosity chart.

COLD WEATHER

RECOMMENDED SAL VISCOSITY GRADE ENGINE OILS

LOOU

J-

FOR THIS SYMBOL

HOT WEATHER “F

7 “C

100 -

+ 38

t 80 -

+ 60 -

+ 27

+ 16

+ 4 0 -

t 4

+ 20 -

- 7

0 -

18 I

1 - 1

I- SAE

IOW-30

ACCEPTABLE IF 5W-30 IS NOT

AVAllABLE

SAE 5W-30 -. .- - . . - -

RECOMMENDED

DO NOT USE SAE IOW-40, SAE 20W-50 OR ANY OTHER VISCOSITY GRADE OIL NOT RECOMMENDED

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As in the chart shown previously, SAE 5W-30 is the only viscosity grade recommended for your vehicle. You should look for and use only oils which have the API Starburst symbol and which are also identified as SAE 5W-30. If you cannot find such SAE 5W-30 oils, you can use an SAE 1OW-30 oil which has the API Starburst symbol, if it’s going to be 0°F (-18°C) or above. Do not use other viscosity grade oils, such as SAE 1OW-40 or SAE 2OW-50 under any conditions. Notice: Use only engine oil with the American Petroleum Institute Certified For Gasoline Engines starburst symbol. Failure to use the recommended oil can result in engine damage not covered by your warranty. GM Goodwrench@ oil meets all the requirements for your vehicle. If you are in an area of extreme cold, where the temperature falls below -20°F (-29”C), it is recommended that you use either an SAE 5W-30 synthetic oil or an SAE OW-30 oil. Both will provide easier cold starting and better protection for your engine at extremely low temperatures.

Engine Oil Additives Don’t add anything to your oil. The recommended oils with the starburst symbol are all you will need for good performance and engine protection. When to Change Engine Oil (GM Oil Life System) Your vehicle has a computer system that lets you know when to change the engine oil and filter. This is based on engine revolutions and engine temperature, and not on mileage. Based on driving conditions, the mileage at which an oil change will be indicated can vary considerably. For the oil life system to work properly, you must reset the system every time the oil is changed. When the system has calculated that oil life has been diminished, it will indicate that an oil change is necessary. A CHANGE ENG OIL light in the Driver Information Center (DIC) will come on. Change your oil as soon as possible within the next two times you stop for fuel. It is possible that, if you are driving under the best conditions, the oil life system may not indicate that an oil change is necessary for over a year.

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However, your engine oil and filter must be changed at least once a year and at this time the system must be reset. It is also important to check your oil regularly and keep it at the proper level. If the system is ever reset accidentally, you must change your oil at 3,000 miles (5 000 km) since your last oil change. Remember to reset the oil life system whenever the oil is changed. How to Reset the CHANGE ENG OIL Light The GM Oil Life System calculates when to change your engine oil and filter based on vehicle use. Anytime your oil is changed, reset the system so it can calculate when the next oil change is required. If a situation occurs where you change your oil prior to a CHANGE ENG OIL light being turned on, reset the system. To reset the CHANGE ENG OIL light, do the following: 1. Turn the ignition key to RUN with the engine off. 2. Fully press and release the accelerator pedal

three times within five seconds.

For vehicles with the Driver Information Center, see Driver Information Center (DIC) on page 3-50 to reset the system.

What to Do with Used Oil Used engine oil contains certain elements that may be unhealthy for your skin and could even cause cancer. Don’t let used oil stay or! your skin for very long. Clean your skin and nails with soap and water, or a good hand cleaner. Wash or properly dispose of clothing or rags containing used engine oil. See the manufacturer’s warnings about the use and disposal of oil products. Used oil can be a threat to the environment. If you change your own oil, be sure to drain all the oil from the filter before disposal. Never dispose of oil by putting it in the trash, pouring it on the ground, into sewers, or into streams or bodies of water. Instead, recycle it by taking it to a place that collects used oil. If you have a problem properly disposing of your used oil, ask your dealer, a service station or a local recycling center for help.

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Engine Air Cleaner/Filter

, ~~

The engine air cleaner/filter is located toward the front of the engine compartment on the passenger’s side of the vehicle.

See Engine Compartment Overview on page 5-12 for more information on engine air cleaner filter location.

Your vehicle may have this feature. The engine air cleanedfilter assembly has an indicator that lets you know when the air filter is dirty and needs to be serviced. The indicator is located on the engine air cleaner/filter air duct.

The service window (A) with the percentage scale shows the amount of engine air cleaner/filter life used. When both service window (A) and service window (B) turn orange, replace the engine air cleaner/filter. After changing the engine air cleaner/filter, press the button on top of the indicator to reset it. For vehicles without an indicator, refer to the maintenance schedule to determine when to replace the engine air cleaner/filter.

5-20

To check or replace the engine air cleaner/filter, do the following: 1. Remove the three screws on the engine air

cleaner/filter and lift off the cover.

2. Twist out the old engine air cleaner/filter and

replace it with a new one, if needed.

3. Reinstall the cover.

Operating the -..gine with the air clear._.Ifilter off can cause you or others to be burned. The air cleaner not only cleans the air, it stops flame if the engine backfires. If it isn’t there and the engine backfires, you could be burned. Don’t drive with it off, and be careful working on the engine with the air cleanedfilter off.

Automatic Transmission Fluid When to Check and Change A good time to check your automatic transmission fluid level is when the engine oil is changed. Change both the fluid and filter every 50,000 miles (83 000 km) if the vehicle is mainly driven under one or more of these conditions:

In heavy city traffic where the outside temperature regularly reaches 90°F (32°C) or higher. In hilly or mountainous terrain. When doing frequent trailer towing. Uses such as found in taxi, police or delivery service.

If you do not use your vehicle under any of these conditions, change the fluid and filter every 100,000 miles (166 000 km).

Notice: If the air cleaner/filter is off, a backfire can cause a damaging engine fire. And, dirt can easily get into your engine, which will damage it. Always have the air cleaner/filter in place when you’re driving.

5-21

How to Check Because this operation can be a little difficult, you may choose to have this done at the dealership service department. If you do it yourself, be sure to follow all the instructions here, or you could get a false reading on the dipstick. Notice: Too much or too little fluid can damage your transmission. Too much can mean that some