Circuit/System Testing
WARNING: This page is about a different car, the 2007 Saturn Outlook. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the RR DEFOG relay.
- Ignition OFF, test for less than 1.0 ohm of resistance between terminal 45 and ground.
- If greater than the specified range, test the relay coil ground circuit for an open/high resistance
- Connect a test lamp between terminal 56 and terminal 45.
- Ignition ON, command the rear defog relay ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
- If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the HVAC Control Module.
- If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the HVAC control module.
- If all circuits test normal, test or replace the RR DEFOG relay.