First post. My '12 997.2 C4 rain-sensing intermittent wipers seem to be speed dependent. When driving at road speed, they are too fast even at lowest sensitivity setting. When at standstill, they are too slow even at max sensitivity. So I am constantly manually readjusting or pulsing the wipers. I'd rather have good old fashioned timed intermittent. Is it possible to reprogram the controller to adjust the sensitivity and the speed dependence? Is it possible to change to basic timed intermittent?
EDIT: btw I don't have the extra PCM functions package.
Thanks

 

In your PCM, you'll have the ability to change this setting under the "Individual Settings" once in that menu you'll see a setting for wipers, you'll be able to adjust accordingly.

 

Thanks for your feedback. Unfortunately I don't have the sport chrono plus pack, so I think I don't have those extra PCM functions. My dealer says it's not possible to program/adjust the rain sensing wipers. Is that really so? Any other advice? Does anyone else have this problem? Maybe there's just something wrong with my wiper sensor or control.

 

Has your windshield ever been changed/replaced?

 

Not to my knowledge. Brand new car from dealer Aug 2011.

 

Huh, mine seems to work pretty well. Maybe something is haywire?

 

Ditto: mine works very well. No speed related issues - truly rain dependent.

There might be a defect in the sensor (round lump behind the rear view mirror). Have you had a rock-chip film put on the window? That will mess with the sensor.

You are in warranty, I'd keep pressuring the dealer.

 

Thanks, I appreciate the feedback. Anyone else with good or bad experience with the rain sensor?

I will definitely followup with the dealer. No chip guard film on the windshield. I do have a hardwired V1 pretty close next to the mirror mount and rain sensor, but I wouldn't think that could cause any sort of interference, could it?

 

Have you experimented with the 3 position switch for the intermittent function?

I hated the rain sensor feature until I zeroed in on the intermittent capabilities, now that I have mastered that I love the feature.

 

I live in the PacNW where it never really rains hard enough for the low setting on most cars and not really light enough to get with the fastest intermittent setting and have found the rain sensing wipers on this car to be one of my (ok, embarrassed to say this) favorite features. They just work. Only complaint would be a random swipe of the windshield in the garage upon start up.

I keep the switch in the lowest of the three settings FWIW.

 

Ditto on the setting

 

I think if you have the power wire from the radar detector running parallel to or wrapped around or near the signal wire from the rain sensor, then the electromagnetic bleed over from the power chord to the rain sensor signal, which is likely a very small signal, could cause havok with that rain sensor signal. The power chord will have all sorts of ignition signal noise and other power consumer noise on it, or could be just creating inductance losses due to the proximity to the rain sensor signal wire.

Try removing the radar detector power cord from the area and try it out again.

If thats the problem, you just need to add some good EMF shielding around the rain sensor wiring (or your radar detector power chord.

 

Sorry I haven't updated this forum in a while. Here is my Rennlist post from last night or the night before:
"Referring to my OP: problem solved. It seems the erratic operation of my 997.2 rain sensor wipers was caused by the cord of my V1 being coiled/wrapped around the little tube (wiring channel) that goes from the rain sensor up to the headliner. I had done that to keep the hardwired cord tidy as it runs to the V1 directly to the right of the mirror mount. As a check, I changed how I run the cord to the V1, without coiling it around the rain sensor's wiring channel, and lo and behold, now the rain sensor wipers work excellently. The V1 cord loops must have caused interference or added enough inductance to the circuit of the rain sensor to screw up the rain sensor signals. Weird, eh?" Just by chance, this might be helpful to someone else out there.

 

Just Slow The Heck Down!

 

I have seen some strange stuff with electronics in the telecoms world in which I work, but this is a first. Good find!