Pinpoint Test 4

PINPOINT TEST 4: THE AUTO-DIMMING REAR VIEW MIRROR DOES NOT OPERATE CORRECTLY

Step 1 - 5:

Step 6 - 9:

Normal Operation
The auto-dimming rear view mirror receives power from circuit (B/P) and ground from circuit (B). If the vehicle is placed in REVERSE, voltage is sent to circuit (B/P) and the auto-dimming rear view mirror will turn the dimming feature off. There are two photoelectric sensors: one in the front of the mirror and one mounted on the glass side of the mirror. If the sensors are blocked, the auto-dimming feature might not work correctly. Always verify both sensors are not physically blocked before attempting to diagnose auto-dimming rear view mirror concerns.

Possible Causes

NOTE: If the backup lamps are on all the time or are inoperative, the auto-dimming rear view mirror will not operate correctly.

- circuit (B/P) open
- circuit (B) open
- auto-dimming rear view mirror