Circuit/System Testing
WARNING: This page is about a different car, the 2018 GMC Terrain and 2018 Chevrolet Equinox. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF/Vehicle OFF, disconnect the X1 harness connector at the A11 Radio and the X2 harness connector at the K73 Telematics Communication Interface Control Module, ignition ON/vehicle in Service Mode.
- Test for less than 1 V between the signal circuit terminals listed below and ground:
- K73 Telematics Communication Interface Control Module signal circuit terminal 1 X2
- K73 Telematics Communication Interface Control Module signal circuit terminal 2 X2
- If 1 V or greater
Repair the short to voltage on the circuit.
- Go to next step: If less than 1 V
- Ignition OFF/Vehicle OFF.
- Test for infinite resistance between the signal circuits listed below and ground:
- K73 Telematics Communication Interface Control Module signal circuit terminal 1 X2
- K73 Telematics Communication Interface Control Module signal circuit terminal 2 X2
- If less than infinite resistance
Repair the short to ground on the circuit.
- Go to next step: If infinite resistance
- Test for less than 2 Ω between the signal circuit terminals listed below:
- K73 Telematics Communication Interface Control Module signal circuit terminal 1 X2 and the A11 Radio signal circuit terminal 20 X1
- K73 Telematics Communication Interface Control Module signal circuit terminal 2 X2 and the A11 Radio signal circuit terminal 19 X1
- If 2 Ω or greater
Repair the open/high resistance in the circuit.
- Go to next step: If less than 2 Ω
- Replace the K73 Telematics Communication Interface Control Module.
- Verify that the Connecting to OnStar® message is heard clearly through the audio system when the OnStar® blue button is pressed.
- If audio is not heard clearly
Replace the A11 Radio.
- Go to next step: If audio is heard clearly
- If audio is not heard clearly
- All OK.