Automatic Dimming Inside Mirror: Test/Replacement

Check for obstructions (parking stickers, labels, etc.) over the front-facing lux level sensor (A).

Fig 1: Identifying Front-Facing Lux Level Sensor, Cover And 7P Connector End View
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Remove the cover (B), then disconnect 7P connector (C).
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
Measure the voltage between terminal No. 2 and body ground.
- If there is less than 0.2 V, go to step 5.
- If there is more than 0.2 V, check for:
  - An open or high resistance in the wire.
  - Poor ground (G401).
Measure the voltage between terminal No. 1 and body ground.
- If there is battery voltage, go to step 6.
- If there is no voltage, check for:
  - Blown No. 12 (7.5 A) fuse in the driver's under-dash fuse/relay box.
  - An open or high resistance in the wire.
Measure the voltage between terminal No. 3 and body ground with the shift lever in Ft (or reverse) position.

If there is battery voltage, replace the mirror assembly.
If there is no voltage, check for:
- An open or high resistance in the wire.
- Faulty driver's under-dash fuse/relay box.
- Faulty transmission range switch (A/T).
- Faulty back-up light switch (M/T).