The vehicles utilize a single, serpentine drive belt for all engine accessories. Serpentine belts are automatically adjusted by the tensioner on the engine. If the belt is loose, check the condition of the belt and tensioner. Make sure the tensioner markings are within proper operating range for belt condition (new/used). The tensioner should place enough tension on the belt so it can only be twisted 90 degrees at it's longest run.
If belt slippage occurs, while the drive belt tensioner is within its operating range, and the belt does not need replacement, check the belt tension as follows:
- Run the engine for 10 minutes, shut OFF the engine, then using a tension gauge between any 2 pulleys, record the belt tension.
- Run the engine for 30 seconds and repeat Step 1.
- Once again, run the engine for 30 seconds and repeat Step 1.
- The belt tension is the average of the 3 readings. Serpentine belt tension should be 105-125 lbs. (467-556 Nm).
- Replace the tensioner if belt length is acceptable (as measured by the tensioner scale), but the tension is below the minimum specification.
Inspect the drive belt(s) for signs of glazing or cracking. A glazed belt will be perfectly smooth from slippage, while a good belt will have a slight texture of fabric visible. Cracks will usually start at the inner edge of the belt and run outward. All worn or damaged drive belts should be replaced immediately.
Removal & Installation
Before servicing the vehicle, refer to the Precautions Section.
NOTEDisconnecting the negative battery cable on some vehicles may interfere with the functions of the on-board computer systems and may require the computer to undergo a relearning process, once the negative battery cable is reconnected.
NOTEIf working near and/or around the SRS system and components, be sure to properly disable the SRS system. See disarming/arming the SRS system.
NOTEFor vehicles equipped with OnStar (RPO UE1), with battery backup, the backup battery is a redundant power supply to allow limited ONStar functionality in the event of a main battery power disruption to the OnStar module (VCIM). Do not disconnect the main vehicle battery or remove the OnStar fuse with the ignition key in any position other than OFF. Retained accessory power should be allowed to time out or be disabled by opening the driver-s side door before disconnecting power. Disconnecting power to the module in any way while the ignition is ON or with the retained accessory power activated may cause activation of the OnStar backup battery system and will discharge and permanently damage the backup battery. Once the backup battery is activated it will stay on until it has completely discharged. The backup battery is not rechargeable and once it is activated, it must be replaced.
- Disconnect the negative battery cable.
- Use a breaker bar and a socket to rotate the serpentine belt tensioner downward (clockwise) relieving the tension from the belt, then remove the belt from the vehicle.
Remove the outlet pipe nuts at the air conditioning compressor, if equipped with a mechanical fan.
- Route the serpentine drive belt over the pulleys, then rotate the tensioner counterclockwise to tension the belt.
- Using the GM diagnostic scan tool or aftermarket equivalent reprogram the necessary systems and components. Be sure to follow the scan tool manufacturer-s directions.