B2476, B2482

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).

B2476, B2482

Important

Before work begins, contact and inform the OnStar Call Centre (OCC) that a service is to be carried out on the unit.

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:

-	Once every driving cycle

Enabling criteria:

-	Ignition ON

-	The battery voltage must be 9.5 - 15.5 V

-	The above conditions are fulfilled for more than 0.3 s.

Fault criteria:

-	Break in the power supply/grounding of the control button unit.

Checking the wiring harness

Jiggle the wiring harness at several points and in different directions to detect intermittent breaks and short circuits. Check switches, connectors and crimp connections for oxidation, withdrawn pins and pin clamping force.

Diagnostic help

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

Diagnostics applies to

Electrical fault in the connecting leads or in the control button unit.