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Old 07-07-2008, 12:54 PM
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EricSilver EricSilver is offline
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Join Date: Mar 2000
Location: Fairfax, VA
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Interesting. This recently happened to me too, on cool, very wet mornings, especially if the car has not been driven for more than 24 hours. But it also happened on Hot, humid mornings, again, if the car had not been driven for more than 24 hours.

Driving a while, then restarting, resolves the problem and the car performs beautifully. I am guessing the fault is caused by some component, such as the brake switch, becoming sticky and needing to warm up/dry out before working properly.

I have not yet replaced the brake switch, but it is now on order. Tire pressure is OK, but I have not checked for dirty wheel speed sensors. The only other issue is a neutral safety switch that is misaligned.

Since you indicated you have replaced your brake switch and the problem persists, I will assume that for me, that will be just the start of tracking down the true problem. (I would think that a bad ETA would be consistently faulty, and not just once in a while.)

Originally Posted by deanyel View Post
1994 E320 with ASR, a little over 100k. Three cold wet mornings in a row - same thing. ASR light comes on, car goes into the limp home mode (strange throttle behavior) and LED readout gives a fault code #6 (idle speed control inoperative). The strange thing is, I shut the car off, check and reset the code, start the car again, and it runs fine for the rest of the day. I tried a new brake light switch but it had no impact. It certainly appears to be temperature / humidity related.

I realize this may point to a bad engine actuator but I'm not quite ready to spend that kind of money - it's not that bad yet and I'm not yet so sure that's the problem. According to my parts supplier he sells a lot of new engine actuators and quite often gets a follow up phone call saying "well that didn't fix it". Any "better news" ideas about what it could be?
2008 E350 4matic / Black/Anthracite

Gone but not Forgotten:
2001 E430 4matic, 206,xxx miles, Black/Charcoal
1995 E320, 252,xxx miles, Black/Grey
1989 260E, 223,00 miles, Black/Black
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