Circuit/System Testing
WARNING: This page is about a different car, the 2007 Chevrolet HHR. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the relay.
- Ignition ON, connect two test lamps in series between the positive terminal at the battery and the relay control circuit terminal at the relay connector.
- Command the relay ON and OFF with a scan tool. A test lamp should turn ON and OFF when changing between the commanded states.
- If a test lamp is always ON, test the relay control circuit for a short to ground. If the circuit tests normal, replace the ECM.
- If the test lamps are always OFF, test the relay control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
- Connect a 30A fused jumper wire between the positive voltage terminal at the battery and the fan voltage supply circuit terminal and verify fan activation.
- If the fan does not activate, test the fan voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the fan.
- Ignition ON, connect a 30A fused jumper wire between the relay switch voltage supply circuit terminal and the fan voltage supply circuit terminal and verify fan activation.
- If the fan does not activate, test the relay switch voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and it's fuse is open, test all connected components and replace as necessary.
- Ignition ON, verify that a test lamp illuminates between the relay coil voltage supply circuit terminal and ground.
- If the test lamp does not illuminate, test the relay coil voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and its fuse is open, test all connected components and replace as necessary.
- If all circuits and the ECM test normal, replace the relay.
IMPORTANT:
This driver may not illuminate some test lamps due to current protection. Connect two lamps in series to reduce current.