Ambient Light Sensor: Service and Repair

Rain/Light Recognition Sensor (G397)

The rain/light recognition sensor can be installed again if it is not damaged when removing it from the retaining plate on the windshield (for example when replacing the windshield). Prior to reuse, ensure the rain/light recognition sensor is stored in a dust-free area, and that the silicone connecting pad is not dirty.

Removing:

- Switch ignition and all electrical consumers off and disengage the key or ignition switch in position 0 (ignition off).

- Remove interior mirror.

- Unclip the wire cover routed over the rain/light recognition sensor.

- Disconnect harness connector - 1 - from rain/light recognition sensor - 2 -.





- Using e.g. a phillips-head screwdriver, pry rain/light recognition sensor - 1 - out of retaining plate - 2 - on windshield.





• While removing, the complete rain/light recognition sensor and not only the upper shell of rain/light recognition sensor must be pried off.

Installing:

Install in reverse order of removal, noting the following:

- Thoroughly clean the area of the windshield inside the retaining plate with isopropyl alcohol.

- Remove the cap from the new rain/light recognition sensor.

• Surface (connecting pads) of rain/light recognition sensor must not be soiled when installing.

• If the surface (connecting pads) of rain/light recognition sensor is soiled, it can be potentially cleaned by applying and then pulling off one or more adhesive strips.

- Insert the rain/light recognition sensor - 1 - into the retaining plate - 2 - on the windshield and press it in securely.





• There must not be any bubbles between the windshield and rain/light recognition sensor connecting pads.

- Connect harness connector - 1 - and secure rain sensor - 2 - by mounting the wire cover.