Automatic Dimming Inside Mirror Acura MDX II

Scheme 10

'07 Canada models and '08-09 models

The automatic dimming inside mirror has a front-facing lux level sensor (A), rear-facing lux level sensors (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 electro-chromic gel to reduce glare. This dimming function is canceled when the transmission is in reverse, or when the automatic dimming off switch (C) is turned OFF.

Scheme 11

Scheme 12

1. Remove the roof console (see «INTERIOR LIGHT SWITCH TEST/REPLACEMENT»(/acura/mdx/ii-2006-2010/remont/interiorillumination-lights/#interior-lights) ).
2. Turn the ignition switch ON (II).
3. Measure the voltage between No. 2 terminal and body ground. If there is less than 0.5 V, go to step 4. If there is more than 0.5 V, check for: An open in the wire. Poor ground (G601).
4. Measure the voltage between No. 1 terminal and body ground. If there is battery voltage, go to step 5. If there is no voltage, check for: Blown No. 21 (7.5 A) fuse in the under-dash fuse/relay box. An open in the wire.
5. Measure the voltage between No. 3 terminal and body ground with the transmission range switch in R position. If there is battery voltage, replace the mirror assembly. If there is no voltage, check for: An open in the wire. Faulty under-dash fuse/relay box. Faulty transmission range switch.

See also:
• INTERIOR LIGHT SWITCH TEST/REPLACEMENT