Circuit/System Testing
WARNING: This page is about a different car, the 2018 GMC Savana 3500, 2018 GMC Savana 2500, 2018 Chevrolet Express 3500, and 2018 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.
- 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.