Rain Sensor: Service and Repair

WM 921219 Removing and installing rain sensor

Removing rain sensor

1. Switch off ignition and remove ignition key.
2. Carefully lever apart the cover on the mirror base with a screwdriver and remove it.





Removing cover from mirror base

3. Push mirror downwards from the mirror holder.





Removing mirror

4. Using a plastic spatula, carefully lever out the rain sensor from the holder.





Levering out rain sensor from holder

5. Disconnect the electrical plug connection.

Installing rain sensor

Information

Limited functionality of the rain sensor if the following points are not observed:

- When assembling the rain sensor, air must not be trapped between the windscreen and the silicone layer on the rain sensor.

- When installing the rain sensor, a temperature of approx. 20°C for the windscreen and the rain sensor must be ensured. If necessary, carefully heat the windscreen with a hot-air gun or similar.

- Contact surface must be free of grease and dirt.

- The silicone surface of the sensor must not be touched by fingers.

- If the sensor is new, remove the protection cap before the sensor is pressed onto the windshield.

- When inserting a new sensor, make sure that no air pockets are caught between the silicone and the windscreen. Air pockets could impair the function of the sensor.

1. Connect the electrical plug, pressing on until it clicks into place.





Installing rain sensor into holder

2. Insert rain sensor into holder and press into place.
3. Hold the rain sensor and push the mirror base onto the holder as far as it will go.





Installing mirror

Information

- Ensure that the mirror base has been pushed completely onto the holder.

4. Position the cover on the mirror base and press together until the cover clicks into place.





Installing cover on mirror base

Information

- When replacing the rain sensor, fault entries may occur in the wiper and in the vehicle electrical system control units. Perform a function test on the rain sensor.

5. Check operation of rain sensor.
6. Using the Porsche System tester, read out and then erase the fault memory of the wiper and vehicle electrical system control units.

Rain sensor function test

WARNING

Danger of crushing or trapping with wipers running.

-> Make sure the wipers are switched on when performing this test.

1. Lock the vehicle and unlock it again.
2. Switch on the ignition and set the pot. on the wiper switch for the windscreen wiper to the lowest position.
3. Set the wiper switch to position 1 and then move the pot. one position higher on each occasion. Actuation of the rain sensor is confirmed by one wiping stroke.
4. Switch the ignition on and put the wiper switch in position 1, moisten your finger with water, and move it over the area of the rain sensor on the outside of the windscreen. The wiper switches on.
5. Connect Porsche System Tester. Select the Wiper menu and read out fault memory.