W203 autolight / sensor message

[taumaan]

Im getting an error message "autolights inoperative"..but they're working fine....ollie seems thinks its the light sensor malfunctioning (he's usually right)...two questions:

1. is it the light sensor or how do i check that it is?
2. how does one remove the sensor? mine seems to be very firmly stuck to the windscreen ....if i need one, best place for a replacement part (A203 820 15 11)?

cheers

 

[whitenemesis]

If the sensor is faulty the lights will be on permanently (if the switch is in the auto position). Also the heating and audio illumination will dim (as the car thinks it's night!)

That part number is wrong doesn't come up with anything, probably superceded. What year is your car?

Try A2038202426 (without rain sensor)

Sensor is held by plastic clips to the frame that is bonded to the screen. If you are trying in this weather the plastic will be very stiff!!

 

[taumaan]

hi

the auto lights come on appropriately and the audio illumination dims in the daytime only...finally manged to get the sensor out...the part number is a2038202426 as you suggested...what next? do i buy a new sensor and try it out? mb wants £20...or any other ideas? thanks

 

[whitenemesis]

Personally I would have the fault codes read first but at £20 for the sensor it's just as cheap!

If the headlights are coming on as expected (i.e. the auto function is working) it would suggest the sensor is ok.

What message do you get now the sensor has been removed?

 

[taumaan]

still says auto lights inoperative...