Rain/Headlight sensor.

[oldjohnny]

Hi Folks.

Car is a 2004 C220 estate. Noticed lately the the auto lights were not coming on as early as they should at dusk. Then a dash warning of light sensor. Changed the sensor but still no change. A friend mentioned that he seemed to remember that warning could be related to and triggered by voltage, possibly a failing battery. Battery did get weak during the icy cold period we had but seems ok now. Anyone have any experience of this?

 

[Blobcat]

I’d charge the battery first and see how it goes - >12.4v with engine off is what the battery needs to be at

 

[oldjohnny]

Cheers. Already carried this out and holding 12.4v ok. Just wondering, after changing the sensor, would the original warning fault need deleted, as it's still being displayed?

 

[mioba]

Some DTC need clearing once offending item is replaced.