Circuit/System Testing
- Ignition OFF, disconnect the harness connector X1 (RPO W49) or X2 (RPO DNP) at the outside rearview mirror.
- Wait 1 minute, test for less than 1.0 ohm between the ground circuit terminal 3 and ground.
- If greater than the specified range, test the ground circuit for an open/high resistance. If the circuit tests normal, replace the appropriate door switch.
- Connect a test lamp between the control circuit terminal 7 and ground.
- Ignition ON, command the mirror heater 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 door switch.
- 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 door switch.
- If all circuits test normal, test or replace the outside rearview mirror glass.