Circuit/System Testing

Inside Rearview Mirror Dimming Malfunction

1. Ignition OFF, disconnect the harness connector at the inside rearview mirror.
2. Test for less than 10 ohms between the ground circuit terminal 8 and ground.
   • If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, Verify that a test lamp illuminates between the ignition circuit terminal 13 and ground.
   • If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
4. Park brake applied, vehicle in REVERSE, verify that a test lamp illuminates between the backup lamp control circuit terminal 9 and ground.
   • If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, refer to Backup Lamps Malfunction (Automatic Transmission) or Backup Lamps Malfunction (Manual Transmission) .
5. If all circuits test normal, test or replace the inside rearview mirror.

Outside Rearview Mirror Dimming Malfunction

1. Ignition OFF, disconnect the harness connector at the inside rearview mirror.
2. Ignition ON, verify a test lamp does not illuminate between the following circuits and ground:
   • Signal circuit terminal 5
   • Low reference circuit terminal 16
   • If the test lamp illuminates, test the appropriate circuit for a short to voltage.
3. Ignition OFF, test for infinite resistance between the following circuits and ground:
   • Signal circuit terminal 5
   • Low reference circuit terminal 16
   • If less than the specified range, test the appropriate circuit for a short to ground.
4. Test for less than 100 ohms between the signal circuit terminal 5 and the low reference circuit terminal 16.
   • If greater than the specified range, test both circuits for an open/high resistance. If the circuit tests normal, test or replace the driver outside rearview mirror glass.
5. If all circuits test normal, replace the inside rearview mirror.