U1500

Read the instructions below then start the fault diagnostic procedure.

Symptom: The LED on the control button unit shows a red light. It is not possible to ring to the OnStar Call Center (OCC).

U1500

Fault symptoms

•	The LED on the control button unit shows a red light.

•	It is not possible to ring to the OnStar Call Center (OCC).

On-Board Diagnosis

Type of diagnosis:

-	Continuous

Enabling criteria:

-	Ignition ON

Fault criteria:

-	Fault in the internal communication in the VCIM.

Diagnostic help

The present fault code is erased directly the fault ceases. The historical fault codes are erased after 50 fault free driving cycles.