Diagnostic Aids

WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 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.
If the prompt "OnStar request ended" is heard without depressing the white "dot" button at the end of the an OnStar® key press, the OnStar® system at one time has made a successful cellular connection out was unable to complete the call. If repeated calls are placed with this result, contact the General Motors Technical Assistance Center.
Inaccurate or aged GPS position may have been due to the temporary loss of GPS signal reception by the vehicle in instances such as driving through tunnels or parking structures which restrict the GPS antenna from a clear view of the satellites in the sky

Fig 1: OnStar® Symptom Diagnosis (Steps 1-6)

Courtesy of GENERAL MOTORS CORP.

Fig 2: OnStar® Symptom Diagnosis (Steps 7-17)

Courtesy of GENERAL MOTORS CORP.