Radio Whine When Using OnStar

When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.

While on the OnStar system, either personal calling or the blue button, there is a whine. The whine is there with the engine off or on, but if the engine is on, the whine changes with the engine speed.

Check the three audio circuits from the VCIM to the radio for opens, shorts to each other and shorts to ground.

Shift the wiring harness around to induce whine

Remove radio and inspect wiring harness.

Peel back and inspect the shielded audio harness a total of 14 inches from the radio.

The harness runs near a bracket behind the radio.

Separate the wires from the tape and trace back on circuit #372 ( black with a white stripe wire that is a ground circuit).

Inspect for a chaffed or shorted wire, (shorting to the shielded audio circuit).

Repair the insulation on the two wires. and verify whine is eliminated.

Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms.