Auto-wiper operation?

[deilenberger]

I guess I'm used to BMW's auto-rain-sensing wipers.. the Cayenne one seems to work quite differently. On the BMW - if it's set for rain-sensing (1) it actually seems to sense when there are rain drops falling. The Cayenne one just sits there wiping away even when there is just a very light mist - without any intermittent operation. (2) the BMW one goes into a very slow intermittent mode when the vehicle is stopped - like at a traffic light. I don't see this happening on the Cayenne (the BMW one also goes into a slow-timed intermittent mode when stopped even if in the manual slow wiper mode.) (3) When the Cayenne wiper is busily wiping away - even with nothing to wipe - I found if I click it down to OFF - and then back to intermittent - it seems to go into a semi-timed mode, related somewhat to the time I had it in the off position. BMW used to have a wiper control that worked this way - non-rain sensing. (4) BMW when it senses torrential rain automatically switches to high-speed wiper operation. I experienced that sort of Biblical rain today - but the Cayenne wiper stayed in slow-speed operation.

Is there something I'm missing or did Porsche just not quite get it right on rain-sensing wiper operation? I've read the manual, and it sounds as if it should work the way I'd expect, but it just doesn't. Something must be amiss (not a-mist.. bad pun intended..) Is there a calibration setting for the rain sensor? (There is on my BMWs - done with the dealer level tools.)

Not dumping on Porsche - just really puzzled how two German cars can have such similar systems that appear to work completely differently.

[bigbuzuki]

Something is not quite right there. It should operate as you expect.

Mine senses the rain, start stops as required with modulated sweeps depending on the stalk settings I have chosen and density of rain.

Sounds like you may have a defect in the rain sensor circuitry.

[wvicary]

You can adjust the sensitivity of the system using the thumb switch on the main wiper switch but it sounds as if your system has a fault.

[therock88]

+1 Mine works as you described with the BMW. Make sure stalk is in the right position. If so, sounds like you may have an issue.

DC

[deilenberger]

The thumb knob adjustment is identical to BMWs I think.. I'm very familiar with using it on my bimmers (many years of driving them..) and I have it set on what I assume is the lowest setting (down, or anti-clockwise looking at the end of the stalk..)

Question: Does the Cayenne system automatically go into a very long interval intermittent when the vehicle is stopped? That's a very nice feature BMWs have had, even before they had rain sensing (on their regular intermittent wipers)..

[odix]

Yes -- the auto-wipe function on Cayenne's (9PA through current) ties wiper interval to vehicle speed. The wipe interval lengthens when vehicle is slow or stopped. The only issue I've had is in heavy snow going 5mph, the wipe-speed may not be as fast as I prefer which is subjective and I can adjust -- but overall it's fine especially in rain at freeway speeds I've been quite impressed. Cayenne's are beasts in heavy rain with the proper tires and sensible driving.

And be sure the auto-wipe function is on, it's easy to inadvertently shut the function off. Your manual covers the details. '04 detail posted below.

The thumb knob adjustment is identical to BMWs I think.. I'm very familiar with using it on my bimmers (many years of driving them..) and I have it set on what I assume is the lowest setting (down, or anti-clockwise looking at the end of the stalk..)

Question: Does the Cayenne system automatically go into a very long interval intermittent when the vehicle is stopped? That's a very nice feature BMWs have had, even before they had rain sensing (on their regular intermittent wipers)..

[deilenberger]

Interesting. The speed sensitive part doesn't appear to be working. The operation sounds as if it should be identical to that on my BMWs.. but it's not. Perhaps the DuraMetric will allow me to reboot that control unit.. :)

[bigbuzuki]

Maybe try resetting the fuses for the rain sensing system.