Diagnostic Aids

2008 Chevrolet Chevy Express G2500, Van Cargo, 6.6 6SECTION Diagnostic Aids
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The customer concern may have been due to a lack of cellular service in a given area or a failure in the National Cellular Network infrastructure that has since been corrected.

OnStar Call Center Remote Function Requests Inoperative

Step Action Yes No
Schematic Reference: OnStar Schematics 
Connector End View Reference: Cellular Communication Connector End Views 
1 Did you perform the Cellular Communication Diagnostic System Check? Go to Step 2  Go to Diagnostic System Check - Cellular Communication 
2 Attempt to honk the horn, operate the lights and lock or unlock the doors on the vehicle.
Does the applicable system operate properly?
Go to Step 3  Go to
3
IMPORTANT: It is necessary to inform the OnStar® Call Center advisor that this call is for vehicle diagnostic purposes.
  1. Contact the OnStar® Call Center by pressing the blue OnStar® button.
  2. Ask the OnStar® advisor to perform a remote function (door lock/unlock, light flash, or horn honk).
Was the attempt successful?
Go to Diagnostic Aids Use the scan tool to access the STID and ESN and contact the General Motors Technical Assistance Center
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.