Caution: The driver can lose control when pulling a trailer if the correct equipment is not used or the vehicle is not driven properly. For example, if the trailer is too heavy, the brakes may not work well or even at all. The driver and passengers could be seriously injured. The vehicle may also be damaged; the resulting repairs would not be covered by the vehicle warranty. Pull a trailer only if all the steps in this section have been followed. Ask your dealer/retailer for advice and information about towing a trailer with the vehicle.
Notice: Pulling a trailer improperly can damage the vehicle and result in costly repairs not covered by the vehicle warranty. To pull a trailer correctly, follow the advice in this section and see your dealer/retailer for important information about towing a trailer with the vehicle.
To identify the vehicle trailering capacity of your vehicle, you should read the information in "Weight of the Trailer" that appears later in this section.
If yours was built with trailering options, as many are, it's ready for heavier trailers. But trailering is different than just driving your vehicle by itself. Trailering means changes in acceleration, braking, 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.
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. |
| • | Consider using a sway control. See "Hitches" later in this section. |
| • | 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. |
| • | 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). See "Tow/Haul Mode" later in this section. |
Three important considerations have to do with weight:
| • | The weight of the trailer |
| • | The weight of the trailer tongue |
| • | The weight on your vehicle's tires |
Tow/Haul Mode
Tow/Haul is a feature that assists when pulling a heavy trailer or a large or heavy load. The purpose of the Tow/Haul mode is to:
| • | Reduce the frequency and improve the predictability of transmission shifts when pulling a heavy trailer or a large or heavy load. |
| • | Provide the same solid shift feel when pulling a heavy trailer or a large or heavy load as when the vehicle is unloaded. |
| • | Improve control of vehicle speed while requiring less throttle pedal activity when pulling a heavy trailer or a large or heavy load. |
Your vehicle may be equipped with a button at the end of the shift lever which, when pressed, enables tow/haul. Your vehicle may be equipped with Autoride® which further improves your vehicle's ride while towing. See Autoride® for more information. When the button is pressed, a light on the instrument panel will illuminate to indicate that Tow/Haul has been selected. Tow/Haul may be turned off by pressing the button again, at which time the indicator light on the instrument panel will turn off. The vehicle will automatically turn off Tow/Haul every time it is started.
Tow/Haul is designed to be most effective when the vehicle and trailer combined weight is at least 75% of the vehicle's Gross Combined Weight Rating (GCWR). See Weight of the Trailer later in this section. Tow/Haul is most useful under the following driving conditions:
| • | When pulling a heavy trailer or a large or heavy load through rolling terrain. |
| • | When pulling a heavy trailer or a large or heavy load in stop and go traffic. |
| • | When pulling a heavy trailer or a large or heavy load in busy parking lots where improved low speed control of the vehicle is desired. |
Operating the vehicle in tow/haul when lightly loaded or with no trailer at all will not cause damage. However, there is no benefit to the selection of Tow/Haul when the vehicle is unloaded. Such a selection when unloaded may result in unpleasant engine and transmission driving characteristics and reduced fuel economy. Tow/Haul is recommended only when pulling a heavy trailer or a large or heavy load.
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.
Use one of the following charts to determine how much your vehicle can weigh, based upon your vehicle model and options.
Maximum trailer weight is calculated assuming only the driver is in the tow vehicle and it has all the required trailering equipment. The weight of additional optional equipment, passengers and cargo in the tow vehicle must be subtracted from the maximum trailer weight.
Vehicle* | Axle Ratio | Maximum Trailer Weight | GCWR |
|---|---|---|---|
C-1500 (2WD)* | |||
4800 V8 | 3.42 3.73 | 5,700 lbs. (2 585 kg) 6,700 lbs. (3 039 kg) | 11,000 lbs. (4 990 kg) 12,000 lbs. (5 443 kg) |
5300 V8 | 3.42 3.73 | 6,700 lbs. (3 039 kg) 7,700 lbs. (3 492 kg) | 12,000 lbs. (5 443 kg) 13,000 lbs. (5 897 kg) |
5300 V8 (Extended Models) | 3.73 4.10 | 7,400 lbs. (3 356 kg) 8,400 lbs. (3 810 kg) | 13,000 lbs. (5 897 kg) 14,000 lbs. (6 350 kg) |
Vehicle* | Axle Ratio | Maximum Trailer Weight | GCWR |
|---|---|---|---|
K-1500 (4 WD)* | |||
4800 V8 | 3.73 4.10 | 6,400 lbs. (2 902 kg) 7,400 lbs. (3 356 kg) | 12,000 lbs. (5 443 kg) 13,000 lbs. (5 897 kg) |
5300 V8 | 3.73 4.10 | 7,500 lbs. (3 401 kg) 7,800 lbs. (3 538 kg) | 13,000 lbs. (5 897 kg) 14,000 lbs. (6 350 kg) |
5300 V8 (Extended Models) | 3.73 4.10 | 7,200 lbs. (3 265 kg) 8,200 lbs. (3 719 kg) | 13,000 lbs. (5 897 kg) 14,000 lbs. (6 350 kg) |
Vehicle* | Axle Ratio | Maximum Trailer Weight | GCWR |
|---|---|---|---|
C-2500 (2WD)* | |||
6000 V8 (Extended Models)**† | 3.73 4.10 | 7,900 lbs. (3 583 kg) 9,900 lbs. (4 490 kg) | 14,000 lbs. (6 350 kg) 16,000 lbs. (7 257 kg)** |
6000 V8 w/4WS** | 3.73 4.10 | 7,600 lbs. (3447 kg) 9,600 lbs. (4354 kg) | 14,000 lbs. (6 350 kg) 16,000 lbs. (7 257 kg) |
8100 V8 (Extended Models)† | 3.73 4.10 | 10,500 lbs. (4 762 kg) 12,000 lbs. (5 443 kg) | 17,000 lbs. (7 711 kg) 19,000 lbs. (8 618 kg) |
**GCWR limited to 14,000 lbs. (6 356 kg) on extended models with Z83 suspension. †2500 extended models (2WD) equipped with Z83 suspension limited to 7,900 lbs. (3 583 kg) trailer. | |||
Vehicle* | Axle Ratio | Maximum Trailer Weight | GCWR |
|---|---|---|---|
K-2500 (4WD)* | |||
6000 V8 (Extended Models)**† | 3.73 4.10 | 7,600 lbs. (3 447 kg) 9,600 lbs. (4 354kg) | 14,000 lbs. (6 350 kg) 16,000 lbs. (7 257 kg)** |
6000 V8 w/4WS | 3.73 4.10 | 7,300 lbs. (3 311 kg) 9,300 lbs. (4 218 kg) | 14,000 lbs. (6 350 kg) 16,000 lbs. (7 257 kg) |
8100 V8**† | 3.73 4.10 | 10,200 lbs. (4 626 kg) 12,000 lbs. (5 443 kg) | 17,000 lbs. (7 711 kg) 19,000 lbs. (8 618 kg) |
**GCWR limited to 14,000 lbs. (6 356 kg) on extended models with Z83 suspension. †2500 Extended Models (4WD) equipped with Z83 base suspension limited to 7,900 lbs. (3 586 kg) trailer. | |||
The Gross Combination Weight Rating (GCWR) is the total allowable weight of the completely loaded vehicle and trailer including any passengers, cargo, equipment and conversions. 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 L1H 8P7
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. If you have a lot of options, equipment, passengers or cargo in your vehicle, it will reduce the tongue weight your vehicle can carry, which will also reduce the trailer weight your vehicle can tow. 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 for more information about your vehicle's maximum load capacity.
The trailer tongue weight (A) should be 10 percent to 15 percent of the total loaded trailer weight, up to a maximum or 600 lbs. (272 kg) for the 1500 series, and up to a maximum of 600 lbs. (272 kg) for the 2500 series with a weight carrying hitch. The trailer tongue weight (A) should be 10 percent to 15 percent of the total loaded trailer weight, up to a maximum of 1,000 lbs.(453 kg) for the 1500 series and up to a maximum of 1,500 lbs. (680 kg) for the 2500 series with a weight distributing hitch.
Do not exceed the maximum allowable tongue weight for your vehicle. Choose the shortest hitch extension that will position the hitch ball closest to the vehicle. This will help reduce the effect of trailer tongue weight on the rear axle.
After you have loaded the trailer, weigh the trailer and then the tongue separately, to see if the weights are proper. If they are not, you may be able to get them right 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 Loading Your Vehicle for more information. Then be sure you don't go over the GVW limit for your vehicle, or the GAWR, including the weight of the trailer tongue. If you use a weight distributing hitch, make sure you don't go over the rear axle limit before you apply the weight distribution spring bars.
Hitches
It's important to have the correct hitch equipment. Crosswinds, large trucks going by and rough roads are a few reasons why you will need the right hitch.
Weight Distributing Hitches and Weight Carrying Hitches
(A) Body to Ground Distance (B) Front of Vehicle
When using a weight-distributing hitch, the hitch must be adjusted so the distance (A) remains the same both before and after coupling the trailer to the tow vehicle.
If you use a step-bumper hitch, the bumper could be damaged in sharp turns. Make sure there is ample room when turning to avoid contact between the trailer and the bumper.
If you will be pulling a trailer that, when loaded, will weigh more than 5,000 lbs (2 270 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 driving. Always use a sway control if the trailer will weigh more than these limits. You can ask a hitch dealer about sway controls.
Safety Chains
You should always attach safety 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.
If you are towing a trailer up to 5,000 lbs (2 270 kg) with a factory-installed step bumper, you may attach the safety chains to the attaching points on the bumper. If you are towing a trailer up to your vehicle's trailer rating limit, you may attach the safety chains to the attaching point on the hitch platform. If you are towing with an aftermarket hitch, following the trailer or hitch manufacturer's recommendation for attaching safety chains. 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 2,000 lbs. (900 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.
If your vehicle is equipped with Stabilitrak, your trailer cannot tap into the vehicle's hydraulic brake system.
Your trailer 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. |
| • | The trailer's brake system will use less than 0.02 cubic inches (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, make the brake tap at the port on the master cylinder that sends the 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.
Driving with a Trailer
Caution: When towing a trailer, exhaust gases may collect at the rear of the vehicle and enter if the liftgate, trunk/hatch, or rear-most window is open.
Engine exhaust contains carbon monoxide (CO) which cannot be seen or smelled. It can cause unconsciousness and even death. To maximize safety when towing a trailer:| • | Have the exhaust system inspected for leaks and make necessary repairs before starting a trip. |
| • | Never drive with the liftgate, trunk/hatch, or rear-most window open. |
| • | Fully open the air outlets on or under the instrument panel. |
| • | Adjust the Climate Control system to a setting that brings in only outside air and set the fan speed to the highest setting. See Climate Control System in the Index. |
Towing 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 all trailer hitch parts 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.
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.
If your vehicle is equipped with four-wheel steering and if you use it while backing your trailer the same rules apply. However, with four-wheel steering your rig will respond more quickly and it may take additional practice to get used to backing up with four-wheel steering.
Making Turns
Notice: Making very sharp turns while trailering could cause the trailer to come in contact with the vehicle. The 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.
Driving On Grades
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, if necessary, a lower gear selection if the transmission shifts too often (e.g., under heavy loads and/or hilly conditions).
You may also want to activate the tow/haul mode if the transmission shifts too often. See "Tow/Haul Mode" earlier in this section for more information.
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 .
Parking on Hills
Caution: Parking the vehicle on a hill with the trailer attached can be dangerous. If something goes wrong, the rig could start to move. People can be injured, and both the vehicle and the trailer can be damaged. When possible, always park the rig on a flat surface.
But if you ever have to park your rig on a hill, here's how to do it:
- Apply your regular brake, but don't shift into PARK (P) yet.
- Have someone place chocks under the trailer wheels.
- When the wheel chocks are in place, release the regular brakes until the chocks absorb the load.
- Reapply the regular brakes. Then apply your parking brake and shift into PARK (P).
- If you have a four-wheel-drive vehicle, be sure the transfer case is in a drive gear and not in NEUTRAL.
- Release the regular brakes.
Caution: It can be dangerous to get out of the vehicle if the shift lever is not fully in P (Park) with the parking brake firmly set. The vehicle can roll.
If the engine has been left running, the vehicle can move suddenly. You or others could be injured. To be sure the vehicle will not move, even when on fairly level ground, use the steps that follow. Always put the shift lever fully in P (Park) with the parking brake firmly set. If the transfer case on a four-wheel-drive vehicle is in N (Neutral), the vehicle will be free to roll, even if the shift lever is in P (Park). Be sure the transfer case is in a drive gear -- not in N (Neutral).When You Are Ready to Leave After Parking on a Hill
- Apply your regular brakes and hold the pedal down while you:
- Let up on the brake pedal.
- Drive slowly until the trailer is clear of the chocks.
- Stop and have someone pick up and store the chocks.
| • | start your engine, |
| • | shift into a gear, and |
| • | release the parking brake. |
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, belts, 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.
Trailer Wiring Harness
Your vehicle is equipped with the following wiring harnesses for towing a trailer.
Basic Trailer Wiring
The trailer wiring harness, with a seven-pin connector, is located at the rear of the vehicle and is tied to the vehicle's frame. The harness connector can be plugged into a seven-pin universal heavy-duty trailer connector available through your dealer.
The seven-wire harness contains the following trailer circuits:
| • | Yellow: Left Stop/Turn Signal |
| • | Dark Green: Right Stop/Turn Signal |
| • | Brown: Taillamps |
| • | White: Ground |
| • | Light Green: Back-up Lamps |
| • | Red: Battery Feed |
| • | Dark Blue: Trailer Brake |
Heavy-Duty Trailer Wiring Harness Package
Your vehicle is equipped with the seven-wire trailer towing harness. This harness with a seven-pin universal trailer connector is attached to a bracket on the hitch platform.
The seven-wire harness contains the following trailer circuits:
| • | Yellow: Left Stop/Turn Signal |
| • | Dark Green: Right Stop/Turn Signal |
| • | Brown: Taillamps |
| • | White: Ground |
| • | Light Green: Back-up Lamps |
| • | Red: Battery Feed |
| • | Dark Blue: Trailer Brake |
If your trailer is equipped with electronic brakes, you can get a jumper harness (electric trailer brake control) with a trailer battery feed fuse from your dealer. This harness and fuse should be installed by your dealer or a qualified service center.
If you need to tow a light-duty trailer with a standard four-way round pin connector, you can also get an adapter.
Instrument Panel Jumper Wiring Harness
Caution: Be sure to use only the correct trailer brake harness, the one intended for use on your vehicle. If you use some other trailer brake harness, even if it seems to fit, your trailer brakes may not work at all. You could have a crash in which you or others could be injured. Use only the trailer brake harness intended for your vehicle. If it is no longer available to you, be sure to get a proper replacement from your dealer.
This harness is included with your vehicle as part of the heavy-duty trailer wiring package.
This harness is for an electric brake controller and includes a trailer battery feed fuse. It should be installed by your dealer or a qualified service center.
This harness is new for your vehicle, and you will not be able to use a harness from an earlier model year.
Four-Wire Harness Adapter
This adapter is included with your vehicle as part of the heavy-duty trailer wiring package.
Use this adapter to connect a standard four-way round pin connector to the seven-wire harness on your vehicle.
Connect the adapter with the tab pointing up (see arrow). The flip cap on the vehicle's seven-wire harness will lock onto the tab and help hold the adapter in place. Plug the four-way round pin connector onto the adapter.
Power Winches
If you wish to use a power winch on your vehicle, only use it when your vehicle is stationary or anchored.
Step-Bumper Pad
Your vehicle has a rear step bumper with a rear step pad at the center of the bumper.
If you will be using the bumper to tow a trailer, and your step-bumper has three cutout circles you must push out the center cutout circle to install the trailer ball.
If your step-bumper has only one cutout circle, you will have to cut out the circle, then remove it to install the trailer ball.
