Circuit/System Verification

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

IMPORTANT:

It is necessary to inform the OnStar® Call Center advisor that this call is for vehicle diagnostic purposes.
It is necessary to have the vehicle in an open outside area where a cellular call can be successfully placed and GPS data can be received from satellites.

Verify that the horn, lights, and the doors locks on the vehicle operate properly.
- If the applicable system does not operate properly, refer to Diagnostic System Check - Vehicle (without HP2) or Diagnostic System Check - Vehicle (with HP2) .
Contact the OnStar® Call Center by pressing the blue OnStar® button. Verify with the OnStar® advisor that all of the remote functions (door locks, lights, or horn) work.
- If unable to connect with the OnStar® call center, refer to Unable to Contact OnStar Call Center .
- If the remote functions do not operate when requested, replace the CIM.