Electrochromic Mirrors BMW M3 E36

DESCRIPTION & OPERATION

The BMW Electrochromic ECTM Mirror automatically detects and eliminates glare coming from headlamps of following vehicles. The ECTM Mirror darkens gradually as glare increases. When glare subsides mirror becomes clear again. The ECTM Mirror has a 3-position switch (OFF/MIN/MAX) to turn on and select sensitivity of mirror. The mirror also has a Reverse gear override function.

MIRROR FUNCTION

1. The vehicle ignition switch must be in ON/RUN position. The OFF/MIN/MAX sensitivity switch on mirror must be in MAX position.
2. Test operation of ECTM Mirror by simulating glare as follows: In full daylight conditions, cover forward facing sensor (located on right side of mirror back) with a dark cloth or piece of opaque material. Hold dark cloth over sensor until you notice mirror start to darken. Remove cloth and mirror should return to clear state. NOTE: In low ambient light of a large workshop mirror may not return to full clear Repeat operation test several times to make sure mirror operates correctly. With mirror in dark, non-reflective stage, place gear selector into Reverse gear. The mirror should return to clear stage. Repeat previous step to make sure Reverse gear override operates correctly.

MIRROR INOPERABLE

1. In a dark area, (i.e. garage) visually check that mirror switch panel legend is illuminated; if it is not, problem could be in electrical wiring to mirror.
2. Use the following procedure to check vehicle electrical wiring: Remove wire cover on mirror foot and disconnect Yellow electrical connector. Using a VOM, check for voltage in vehicle connector at Pin 3 (+1 2V,IGN. SW ITCHED). Check for continuity to Pin 1 (GROUND). Use a VOM to check Pin 2 for + 12V with gear selector in Reverse gear.

Scheme 1

Connector Terminal Identification

1. Pin 1 is Vehicle chassis ground (Brown wire).
2. Pin 2 is Reverse override (+12V, gear selector in reverse) (Blue/Yellow wire). Mirror changes to high reflectance when input is energized.
3. Pin 3 +12V, IGN. SWITCHED (Green/Red wire).

Removal & Installation

1. If mirror wiring checks okay and mirror does not operate, replace mirror. Disconnect electrical connector. Remove mirror from windshield button by pulling mirror foot directly toward you at a 90-degree angle from windshield.
2. Install replacement mirror by placing mirror foot over windshield mounting button and rotating down 30-degrees to lock into proper position. Reconnect wiring harness connection mirror bracket base and test mirror operation. Replace wire cover.

WIRING DIAGRAMS

Note. For wiring diagram, see appropriate diagram in SYSTEM WIRING DIAGRAMS in WIRING DIAGRAMS.