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Discussion Starter · #1 ·
Well, my ABS & Brake light came on for the second time in two weeks yesterday. When I brought the car in last time, I was told that they couldn't find anything wrong and that if it happened again, to bring the car back. Does the car only record an actual failure code after it happens twice?

Also, the ABS wasn't the only thing that failed yesterday. When I pulled out of my friends driveway, I noticed the my speedometer decided to stop working. I'm guessing the issue is a faulty wheel sensor that is also tripping the ABS. :dunno:

Anyone else have this problem or have any suggestions as to what it might be?

Thanks guys!
 

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I used to work for the company that does the braking system for the 3er, and from what I remember, all fault codes related to wheel speed sensors are stored. Tell your dealer to check them, they should still be there!
 

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Rest in peace, Coach
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When you slam on the brakes, does your ABS still activate?
 

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Discussion Starter · #4 ·
The HACK said:
When you slam on the brakes, does your ABS still activate?
It's funny you asked this b/c that was one of the first things I did. The wheels locked up.

I just dropped off the car at the dealership and guess what . . . when I started the car in the parking garage at work, everything was normal (no error lights and the speedo worked). Right before this, when I was speaking to my dealer I had made a comment of "how much do you wanna bet when I give the car to you guys, everything is fine?". I took a digital photo of the speedo at zero with my tach at 3000 rpm on my way to work this morning and showed it to the service manager, so they didn't have to say they couldn't duplicate the problem.

The funny thing about all of this is the last time this happened it was right after I had spent an hour cleaning my wheels and soaking them with water. The next day everything was fine. The ABS light didn't come on when it was raining though.:dunno:

I wonder if the water somehow shorted out the sensor, b/c on both occasions, after the car sat overnight, everything went back to normal.
 

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Hm...I soak my wheels all the time when I wash and never had that problem. All the wires are insulated on the ABS sensor I believe, and if I'm not mistaken it's just a small magnet that senses a small notch on the hub that passes by so WATER definately won't short it out. What is strange is that it's intermitten...When it fails it FAILS.

Is it right after you've done all the audio stuff? One possiblity I can think of, and trust me, your dealership may be thinking of the same thing, is that the audio installer may have tapped into a powersource shared by the ABS sensors or a grounded a wire that's shared by the ABS sensors, and that's triggering an intermitten failure. The ABS sensor is actually fairly easy to replace I believe, if I were you and the dealership refused to service the car (not unlikely) due to all the aftermarket goodies you added, I'd go out and buy a new ABS sensor and a Bentley's manual and DIY.
 

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Discussion Starter · #6 ·
The HACK said:
Hm...I soak my wheels all the time when I wash and never had that problem. All the wires are insulated on the ABS sensor I believe, and if I'm not mistaken it's just a small magnet that senses a small notch on the hub that passes by so WATER definately won't short it out. What is strange is that it's intermitten...When it fails it FAILS.

Is it right after you've done all the audio stuff? One possiblity I can think of, and trust me, your dealership may be thinking of the same thing, is that the audio installer may have tapped into a powersource shared by the ABS sensors or a grounded a wire that's shared by the ABS sensors, and that's triggering an intermitten failure. The ABS sensor is actually fairly easy to replace I believe, if I were you and the dealership refused to service the car (not unlikely) due to all the aftermarket goodies you added, I'd go out and buy a new ABS sensor and a Bentley's manual and DIY.
I had this same problem prior to the audio install. Since they couldn't duplicate it, they just told me to come back if it acted up again. I had no problems since picking up the car at the audio shop on Friday. I drove over 600 miles round-trip to Albany, NY and no problems until I washed the car.:dunno: It is rather odd.

Edit: Hack, do you know if the ABS sensor would kill the speedometer? The last time the ABS light went on, I didn't have any problems with the speedo.
 

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Discussion Starter · #7 ·
Hack,

My service guy just called and said that it was the ABS control module that is failing. They had to order the part, so everything should be back together on Friday. Also, no problems with the warranty work.

Adam (the service manager) said the whole shop was all over the car, checking out the audio setup. :D I just hope they didn't test to see how loud it gets.
 

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Ackster said:
Hack,

My service guy just called and said that it was the ABS control module that is failing. They had to order the part, so everything should be back together on Friday. Also, no problems with the warranty work.

Adam (the service manager) said the whole shop was all over the car, checking out the audio setup. :D I just hope they didn't test to see how loud it gets.
Haha, see now you've got some recognition around there. They'll treat you good man. Too bad about the ABS sensor, what's next on the list of things to go wrong? :dunno: :thumbdwn:
 

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The HACK said:
Hm...I soak my wheels all the time when I wash and never had that problem. All the wires are insulated on the ABS sensor I believe, and if I'm not mistaken it's just a small magnet that senses a small notch on the hub that passes by so WATER definately won't short it out. What is strange is that it's intermitten...When it fails it FAILS.
Newer wheel speed sensors use integrated microprocessors that output square wheel speed signals rather thant the sine-wave signals that magnet-based sensors output.

And yes, they are insulated. But, nothing is truly insulated. Every material has porosity. Even wire insulated is specified by how many pinholes are in it per meter. Gotta keep those costs down. . .
 

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Discussion Starter · #10 ·
webguy330i said:


Haha, see now you've got some recognition around there. They'll treat you good man. Too bad about the ABS sensor, what's next on the list of things to go wrong? :dunno: :thumbdwn:
Hopefully this is it with the problems. :dunno: I've only had two real issues, one was the throttle (which since being fixed has not recurred :thumb:) and then the ABS sensor. I'm hoping after Friday, my car will be in the condition it should have been in when I picked her up at the dealership last month. New cars and their odd quirks. . .
 

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Ackster said:


I had this same problem prior to the audio install. Since they couldn't duplicate it, they just told me to come back if it acted up again. I had no problems since picking up the car at the audio shop on Friday. I drove over 600 miles round-trip to Albany, NY and no problems until I washed the car.:dunno: It is rather odd.

Edit: Hack, do you know if the ABS sensor would kill the speedometer? The last time the ABS light went on, I didn't have any problems with the speedo.
The speedometer gets its numbers from the ABS sensors...It senses how many times the wheel rotate around and multiply it by an assumed radius of the wheel. I believe it's measured over the rear wheel?
 

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I'm pretty sure it's measured over the rear and front wheels, averaged across all 4 if you will. I only say that because I noticed once when I did a "slight" burnout that the speedometer sat at around 20mph, when I was barely moving forward and when the tires caught traction the speedometer jumped to around 45mph very quickly.

It hasn't done that since, and I haven't done a burnout since either. :dunno:
 

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Rest in peace, Coach
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webguy330i said:
I'm pretty sure it's measured over the rear and front wheels, averaged across all 4 if you will. I only say that because I noticed once when I did a "slight" burnout that the speedometer sat at around 20mph, when I was barely moving forward and when the tires caught traction the speedometer jumped to around 45mph very quickly.

It hasn't done that since, and I haven't done a burnout since either. :dunno:
Next time I have my car up on jackstands, I'll rev the engine and put it in gear and see what happens. :)
 

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The HACK said:


Next time I have my car up on jackstands, I'll rev the engine and put it in gear and see what happens. :)
"Ferris! It's not working... The miles aren't coming off. The miles aren't coming off running it in reverse"
 

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Discussion Starter · #17 ·
I am still waiting for the ABS Control Module to come in. The speedo stopped working again last night . . . sigh. Well, on my way to work this morning, the Service Engine Soon light came on.
Would this have anything to do with the fact that the speedo hasn't worked for about 80 miles or so, or is it a new problem cropping up (I can't win, this car just doesn't want to stay fixed it seems)? The car isn't driving any differently.
 

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Ackster said:
I am still waiting for the ABS Control Module to come in. The speedo stopped working again last night . . . sigh. Well, on my way to work this morning, the Service Engine Soon light came on.
Would this have anything to do with the fact that the speedo hasn't worked for about 80 miles or so, or is it a new problem cropping up (I can't win, this car just doesn't want to stay fixed it seems)? The car isn't driving any differently.
:yikes: :bawling:
 
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