Automatic Dimming Inside Mirror Acura TL III

Scheme 11

System Description

The automatic dimming inside mirror has a front-facing lux level sensor (A), a rear-facing lux level sensor (B), and a control unit. The control unit receives signals from each sensor. Based on the difference between the two lux levels (the light outside the vehicle and the light from the headlights of the other vehicle, etc.), the control unit controls the electrochromatic gel to reduce the glare. This dimming function is canceled when the transmission is in reverse, or when the automatic dimming off switch (C) is turned OFF.

Scheme 12

Scheme 13

1. Remove the roof console (see «INTERIOR LIGHT SWITCH TEST/REPLACEMENT»(/acura/tl/iii-2003-2006/remont/interiorillumination-lights/#interior-lights) ).
2. Disconnect the 3P connector (A) from the automatic dimming inside mirror (B).
3. Check for continuity between No. 3 terminal and body ground. If there is continuity, go to step 4. If there is no continuity, check for: An open in the wire. Poor ground (G503, G601).
4. Check for voltage between No. 1 terminal and body ground with the ignition switch ON (II). If there is battery voltage, go to step 5. If there is no voltage, check for: Blown No. 20 (7.5 A or 15 A) fuse in the under-dash fuse/relay box. An open in the wire.
5. Check for voltage between No. 2 terminal and body ground with the ignition switch turned ON (II) and transmission range switch (A/T) or back-up light switch (M/T) in reverse. If there is battery voltage, replace the mirror assembly. If there is no voltage, check for: An open in the wire. Blown No. 21 (7.5 A) fuse in the under-dash fuse/relay box. Faulty under-dash fuse/relay box. Faulty transmission range switch (A/T) or backup light switch (M/T).

See also:
• INTERIOR LIGHT SWITCH TEST/REPLACEMENT