SAAB WIS ONLINE

OnStar control button unit, one or more buttons are not functioning

Read the instructions below then start the fault diagnostic procedure.

Symptom:

OnStar control button unit, one or more buttons are not functioning



Important

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


Conditions

No trouble codes stored in the car for the current fault symptom.

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 Check switches, connectors and crimp connections for oxidation, withdrawn pins and pin clamping force.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 control button unit incorporates three resistors connected in series which are supplied with 10 V from the VCIM. When a button is depressed the related resistor (button) is grounded and so generates the specific voltage/signal.


- Emergency 2.8 V

- OnStar Services 1.6V

- White Dot 0.45 V