Circuit/System Testing
WARNING: This page is about a different car, the 2007 Cadillac STS. However, it is still accessible from the selected car via links, so may be relevant.
IMPORTANT:
With a scan tool perform the microphone test under amplifier special functions menu. If the microphone passes the microphone test the system is OK.
- Turn the ignition ON, Disconnect the noise compensation microphone.
- Measure for 7 V to 9 V between the noise compensation microphone supply circuit and the drain circuit.
- If the voltage is in between 9 to 7 V, replace the noise compensation microphone
- If the voltage is greater than 9 V or less than 7 V and a open, short to ground, or short to voltage can not be found, replace the radio.