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Discussion Starter #1
My 1999 328i has an intermittent fault that occurs only when wet. I have narrowed it down to rain, washing the car, and heat/humidity over 90%. I've read the other ASC threads and they don't cover this exact symptom. Several referred to a wheel sensor or alternator for a permanent failure.

When dry, there is no fault. If I drive into rain (or wash the car) and the ABS, ASC, and Parking Brake lights come on - right about the time one would need to have the ASC working!?!?!? : puke:

Once dry again, it functions normally.

I'm over 2 hours from the nearest bimmer dealer, so a quick trip for diagnosis isn't feasible.

Any leads for a home garage mechanic to troubleshoot this would be appreciated.

Thanks.
 

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I only have that problem when I do long burnouts in the rain all the way through fourth gear. It fixes itself after normal driving for a few km.
 

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Ubergeek
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The ABS sensors on each wheel are easy to remove once the wheel is off. Perhaps you can see if any of them are loose, allowing water to mess up the sensor?
 

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Same thing happens with my 99 323i, but I never made the connection of it only happening when wet. Mechanic said one of my sensors in the rear needs to be replaced.
 

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Happened to my E36, it was a wheel sensor. Initially it failed when it was damp out or raining.
 

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I've put on about 100,000 miles on my 2000 328i over the past 3 years and have had that problem many times. ABS light comes on exactly as you say, wet conditions and even higher himidity. Initially, I had a bad sensor diagnosed by dealer so had them change the sensor. I've basically ignored the latest ABS failure indicators and waited for weather to change. The ABS sensors have a magnet imbedded in them and they will collect iron filings over a period of time. These filings may have an effect on the sensor as well.

If you do decide to change out sensor yourself, you will have to reset the computer because the fault code will still be there and show up as an ABS failure.

Good luck!
 

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Discussion Starter #7
Thanks to all the recommendations on the wheel sensors. I will do some more research on them.

Has anyone replaced all 4 by themselves and reset the computer? If so, where is the best online source to purchase the sensors and the OBD handheld to clear the code?

Thanks again for all the feedback.:thumbup:
 

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You know I have the same problem. So I washed wheel well at a time to see what happens... I think the connectors let water in to short them out briefly until they dry out and then they are fine. So I was debating on whether to just cut the plugs off and solder them. I don't even think the sensors care about the polarity.
 

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Resident Curmudgeon
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FOURTEEN year old thread...

But the sensor is a winding encased in plastic. When the plastic cracks, water can get in and change the electromagnetic characteristics. Dealt with this on an E39 ... proll 14 years ago!
 

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I agree, but now my daughter drives the car and I don't want her to get hurt driving it. ABS activates in turns which is annoying. BMW doesn't sell the plugs to fix this issue for older cars on the road. So I'm thinking the only fix is to solder the connections.
 

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BMW doesn’t sell ABS plugs?!??!
So your fix is to disable ABS?

Got it
 

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Nope looked everywhere. Soldering the abs sensor to the wires would just eliminate the plug and replace option. Abs still there and functioning as intended.
 

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Nope looked everywhere. Soldering the abs sensor to the wires would just eliminate the plug and replace option. Abs still there and functioning as intended.
Oh, sorry. I was thinking you are bypassing the sensor. By "plug" you were meaning 'connector part'. My bad.
 

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Depending on what is wrong with yours, there are a lot of used connectors on line, no?
 

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