Circuit/System Testing

Verify the OnStar® voice recognition is operating normally.
- If the OnStar® voice recognition is inoperative, refer to OnStar Microphone Malfunction .
Ignition OFF, disconnect the radio harness connector X2 and CIM harness connector X2.
Test for less than 1 volt on the voice recognition audio signal high circuit radio harness connector terminal 4 and ground.
- If greater than specified value, test the circuit for a short to voltage.
Test for greater than 1 ohm between the voice recognition audio signal high circuit radio harness connector terminal 7 and ground.
- If less than specified value, test the circuit for a short to ground.
Test for less than 1 ohm between the voice recognition audio signal high circuit radio harness connector terminal 7 and the voice recognition audio high signal circuit CIM harness connector terminal 1.
- If greater than specified value, test the circuit for an open/high resistance.
Test for less than 1 volt on the voice recognition audio signal low circuit radio harness connector terminal 15 and ground.
- If greater than specified value, test the circuit for a short to voltage..
Test for greater than 1 ohm between the voice recognition audio signal low circuit radio harness connector terminal 15 and ground.
- If less than specified value, test the circuit for a short to ground.
Test for less than 1 ohm between the voice recognition audio signal low circuit radio harness connector terminal 15 and the voice recognition audio signal low circuit CIM harness connector terminal 2.
- If greater than specified value, test the circuit for an open/high resistance.
If all circuits test normal, replace the radio.