Circuit/System Testing
- With a scan tool, verify DTC U0100-U0299 or U2105-U2199 is not set as current.
- Ignition OFF, test for less than 5 Ω between the applicable module ground circuit and ground.
- If greater than the specified range, test the circuit for an open/high resistance.
- Ignition OFF, disconnect the applicable module harness connector.
- Ignition ON, verify a test lamp illuminates between the following circuits of the applicable module and ground:
- The battery positive voltage input circuits
- The battery positive voltage output circuits
- The ignition voltage input circuits
- The ignition voltage output circuits
- The switched battery positive voltage supply circuits
- If the test lamp does not illuminate, test the circuit for an open/high resistance. If the circuit fuse is open, test the circuit for a short to ground. If the circuit tests normal, replace the applicable control module.
- Ignition OFF, test for less than 5 Ω between the non-communicating modules GMLAN serial data circuits and the module reporting DTC U0002.
- If greater than the specified range, test the circuit for an open/high resistance.
- If all circuits test normal, replace the applicable control module.