Part 2
So, do we really need to bypass sensors every time and rely on manual switches? No. There could be some reasons to sensors not working properly and wipers or lights are not turned on automatically.
What can affect the functionality of sensors?
There are limitations to both sensors, as some conditions are too complex for a computer to understand.
The rain sensors can be thrown off by debris or dirt on the windscreen which alters the amount of light reflected back, the dirt can also affect the light sensors which are blocked off from any light. This can be remedied with a spurt of windscreen wiper fluid and a quick wipe across the windscreen. If the light persists then you may want to have a car wash.
The light sensor is also thrown off by fog or during intense rainfall since some light can still be detected. Light sensors only detects light so sometimes, it cannot distinguish if the darkness level is due to sunset or just temporary blackout in the middle of the day, so they comes out ON when something block the sunlight or when the driver is just parking.
But sometimes, it could happen that your automatic headlights are turning on and off automatically when there is no rain or when it is still bright outside or vice versa; so in that case, without jumping to the conclusion that the sensors are failed, it is recommended that give your car some time to adjust for the changes in outside environment. For example, If you are driving through or the car sits in a cold and dark outside, it may happen that sensors couldn’t adapt quickly to that change and altered their function. You can try parking your car in some warm and bright place for 1-2 days to check if the sensor came back to its proper functionality. If not, then you can be assured that definitely the sensor has failed.
Replacement is the only Fix!
You can fix your error code by replacing the old, faulty sensor with a new one. This is a simple, quick and easy procedure which may be followed step by step for proper installation.
But before replacing old rain light and humidity sensor try to leave car at warm place for example a garage etc. as sometimes sensor gots confused and brings that fault, sometimes it does work, sometimes it doesn’t, but before spending money and time to replace it try this free advice, because this kind of “fix” is mostly of times working on mercedes-benz cars.
If after trying cleaning and leaving car at warm place fault message doesn’t dissapear, you’ll have to replace it with new part.
Removal Instructions:
Remove vehicle-specific cover on inside of windshield
Carefully disconnect electrical connector from connector housing
Gently press down retaining spring and use a small screwdriver to release from the lock
Release the sensor and gel pad from the windshield by slowly and repeatedly pulling on the plug side without exerting force, and remove.
Installation Instructions:
Posted Jan 17, 2022 (2 years ago)