I had a very large rock hit the windshield recently and needed a new one (there were glass pieces on the dash!). A pretty reputable company replaced it, but now the rain sensing wipers don't work (in fact, if it is in the Auto setting, they always wipe once on start up, but don't wipe again). The Auto headlights also have issues. They'll sometimes work OK, but most times will either fail to turn on in the dark or will stay on in the bright sunshine.

I tried pulling the fuse and resetting it, but no improvement. Is there any other computer reset/calibration that needs to be done for it to work again?

 

I've heard of other people having this problem when not using genuine pilkington windshield.

Call the dealer and see what they say. Maybe you can get the glass company to warranty the work.

 

Take a look at the rain sensor from the outside of the glass, behind the mirror.

If you see any bubbles inside the small rectangular cutout there, that is your issue. You may be able to pull the sensor back off and place back on without the bubbles, or may end up needing a new rain sensor.

 

No bubbles that I can see. Sprayed some water on it and of course it works when I do that, but didn't work yesterday in light rain.

Took the cover off and looked at the sensor, everything is plugged in and secured. Auto headlights worked fine this morning, but would not turn on when I went into the same long tunnel last night.

Sometimes working is more frustrating (and dangerous) than not working at all.

Would it be worth pulling off the old purple lens, cleaning it, and reapplying? Maybe it wasn't put on correctly?

 

So looking through the manual I found this:

1 . To install, reverse the removal procedure. Configure a new sensor using T4

Does anyone know if the IIDtool has the capability to configure the rain/light sensor or am I stuck trying a dealer?


Found this in a T4 list of updates from 2005, looks like what I'll need to get done.

Rain Sensor Reset
If the Rain Sensor ECU is not functioning correctly then there is now an option to reset the values
learnt. This means that the Rain Sensor ECU does not need to be replaced in the case of poor
screen adaption.

 

Currently struggling with the same issue... had oem glass installed. However auto lights didnt work before now they do... now the wipers dont work fml!!

Im at the stage of getting a new sensor

 

I'm considering the following course of action, I'll let you know it goes:

1. Call the dealer and ask if they can reset the rain sensor ECU or do some sort of calibration.

2. Buy a new adhesive pad, peel off the purple lens on the windshield, clean it up, and re-apply (this has worked for some people).

3. Buy a new sensor.