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Discussion Starter · #1 ·
I've searched through the forum and found a few similar issues however I wasn't able to locate anything that didn't have additional symptoms.

Problem: The ABS and ASC lights stay on.

Details: No other lights are on (no brake light), and the brake fluid is about 0.25" from the max line. I disconnected the battery (both terminals) for 10 minutes reconnected it and the lights were still on. I've read where some people say the ABS sensors need replaced however my red brake light isn't illuminated.

How it occurred: Everything was good until about 1 - 1.5 months ago we were going up a rather steep incline which was snow covered. We were about 85% of the way up and then we started to spin the rear tire(s) (not sure if it was one or both). We proceeded to back down the hill and park somewhere safe while someone with all wheel drive came and picked us up. On the way home both the ABS and ASC lights came on. The next day they were on but then went off after restarting the car. When I pressed down the brake pedal it didn't seem normal, almost as if the hydraulics were gone. Then the lights came on and the pedal felt normal. The lights would go on and off over the next few days and then they just stayed on.

I thought I may have burned some tread off that night which caused the sensor to light up and cause the issue. Yesterday I swapped out my winter rims with my spring rims (only ~4000 mi on them). The light is still on, I turned the key over about 5 or 6 times and then I began my search.

Can anyone give some ideas of where to begin troubleshooting?
 

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I found many posts using "abs asc lights on".
I agree with Ed.

Tons and tons of posts with just ABS and ASC (or DSC) bifecta.

The main link is the one Ed already gave you, which covers the trifecta (same problem it seems as the bifecta, in most cases).

For specific bifecta links, see these but note that they're not as good as the one Ed already gave you:

- People with the amber ABS DSC (or ASC) bifecta (1) (2) (3) (4) (5) (6) (7) (8)

BTW, I repeat, if you had searched, you would have found all these ... and more.
 

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Thanks for the update, The Multi Meter test is under one of those links bluebee posted. I was inquiring because I'm having a difficult time getting readings that make sense. Did your indie to the module rebuild?
 

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Ok ! I have been reading the forums and try to learn as much as I can from you guys experiences. Regardless of the field you are dealing in I believe there is always something that triggers certain condition. My 2002 525i has recently been affected by the DSC/ABS/BRAKE warning bug. It is important for me to understand if anything triggered it or it was just a case of old age. Well PittTrack mentioned something very important to me. My saga started after i parked my car on my steep driveway because I was doing some work on my front yard. I recall going to get the car to drive it down and the lights came on. Now few days before I had done my smog test and experienced a temporary ABS warning light as it is normal ( My mech told me that) but after driving 2 miles went away. So I thought maybe this light was a result of that. Never the less after one day the light went out. I drove it for I believe 4 days without warning lights and in all these days I had parked my car on a steep driveway, turning the wheel all the way for safety precaution. Then it happened, the intermittent warning light, gone when shut off the car and on few minutes after i drove it. Sometimes the trifecta sometime only brake and DSC. My cruise and speedo work fine and it seems my ABS also work cause when I hit brake hard there is a raucous noise of the pump pulsating. I will concentrate on 1) sterring column angle sensor or speed sensor as soon as this damn rain in california stops ( my garage is full of junks lol). But I do beleive of a connection.
I will report back as soon as I find something to share in this board
 

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Discussion Starter · #11 ·
Update from the OP?
I took my time reading up on the posts which were linked by you and Ed. I crawled under the car earlier today only to find that the sensors don't look too good. On the front I took a look at the right side and saw that part of the housing was gone. By gone I mean the part which the screws make contact with. I then found that the sensor appears to be stuck after removing the screws. I left it as it was and put the screws back in. I removed the front left wheel and found the sensor in better condition and when I went to take the one screw out it broke off. I pulled the rear right wheel and saw that again some of the plastic housing was missing and then put the wheel back on.

I didn't bother to diagnose anything else as I'm believing that the sensors are the culprit. I'm going to order two front and two rear sensors this weekend (still not sure what brand or where to buy from yet) and then I think I'm going to get a few spare screws and replace them all.

To replace the broken screw I'm thinking that I'll have to take the caliper off and remove the rotor so I can drill the hole out and then tap it. Anyone have some input on this?

Also I stumbled upon one of those links in my search however I didn't realize that if the brake light wasn't lit that the issues were still related. Thanks again for the assistance and any tips on the broken screw would be welcomed.

One final thing... I searched for Staburags NBU 12/K and wasn't able to locate anyplace that sells it. The writeup says to use an equivalent grease, would dielectric grease work on this or should I get something else like while lithium grease?
 

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Okay, I just replaced all 4 sensors and disconnected the battery for about 10 minutes, drove around the block but still the problems remain. ABS, DSC, SES (all amber), no speedo, no odometer, no cruise, steering wheel auto-tilt has a mind of it's own. What should I do next?
 
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