Circuit/System Testing

WARNING: This page is about a different car, the 2018 Chevrolet Bolt EV. However, it is still accessible from the selected car via links, so may be relevant.

Ignition/Vehicle & All vehicle systems - Off
Disconnect the electrical connector: X1 @ A11 Radio & X2 @ K73 Telematics Communication Interface Control Module
Ignition - On/Vehicle - In Service Mode
Test for less than 1 V between the test points:
- K73 Telematics Communication Interface Control Module - Terminal 1 & Ground
- K73 Telematics Communication Interface Control Module - Terminal 2 & Ground
- If 1 V or greater
  Repair the short to voltage on the circuit.
- Go to next step: If less than 1 V
Test for infinite resistance between the test points:
- K73 Telematics Communication Interface Control Module - Terminal 1 & Ground
- K73 Telematics Communication Interface Control Module - Terminal 2 & Ground
- 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 ohms between the test points:
- K73 Telematics Communication Interface Control Module - Terminal 1 & A11 Radio - Terminal 10
- K73 Telematics Communication Interface Control Module - Terminal 2 & A11 Radio - Terminal 9
- If 2 ohms or greater
  Repair the open/high resistance in the circuit.
- Go to next step: If less than 2 ohms - Replace the component:
  Go to next step: K73 Telematics Communication Interface Control Module
Perform a test call with OnStar and verify the OnStar advisor is heard clearly.
- If the component does not work as specified
  Replace the component: A11 Radio
- Go to next step: If the component works as specified
All OK.