Failing ABS Pump

[Hellrot Sachin]

Hey all. So my 99 M3 has been having the ASC and ABS lights come on intermittently. The lights turn on once the car starts rolling (not after the engine starts) and stay on for the duration of the drive with the ABS system not working. My shop initially thought it would be a wheel sensor but after reading the codes, they say it's a failing ABS pump (a $1200 part). The lights only come on intermittently and I picked up a used pump at quite a discount, but I was wondering if anyone else's pump has failed and if the symptoms match the problem. Thanks!

Sachin

[SmellyGreek]

A common fix is to rewire the leads in the pump. Do a search and you'll find more info.

[EricP]

Rarely is it actually the ABS pump from what I have seen users report here. I had all kinds of frigging codes in my system until they were cleared and I ran it for a few days again. Actual culprit for symptoms identical to yours: pedal travel sensor (located on the brake booster.) I would check and re-check codes after clearing them.. it's certainly worth a second look for $1200.

[ASCH MAN]

Rarely is it actually the ABS pump from what I have seen users report here. I had all kinds of frigging codes in my system until they were cleared and I ran it for a few days again. Actual culprit for symptoms identical to yours: pedal travel sensor (located on the brake booster.) I would check and re-check codes after clearing them.. it's certainly worth a second look for $1200.

+1

[TomG]

I had exactly the same symptoms, grabbed a used ABS pump assembly on ebay for $49... problem solved. When I scanned the codes prior to replacement with a Snap-On 2500, the codes were for a bad relay or bad pump motor.

[clumpymold]

If anyone wants to give the Brake Pedal/Booster Sensor a try, I have one brand new for sale. Shoot me an email:

clumpymold@sbcglobal.net

I paid about $130 for it but will sell it for cheap.

[darkpoeticken]

The brake booster sensor was the fix for my problem. I had the exact same symptoms. This problem seems kind of common, too. The issue is that no one ever seems to be able to figure it out without an expensive diagnosis.

[Hellrot Sachin]

clumpy.. any idea on how much labor time to install it? Is there a way to figure out if the brake pedal sensor is the problem without actually replacing it? The OBD2 diagnostics pointed to the ABS pump?!?

[clumpymold]

clumpy.. any idea on how much labor time to install it? Is there a way to figure out if the brake pedal sensor is the problem without actually replacing it? The OBD2 diagnostics pointed to the ABS pump?!?

Labor time? Took me all of 5 minutes to test it out. And undo it. It's VERY easy. Remove clip around original sensor, pull out old sensor, put new one in. I can give you a link to the write-up if you're interested in purchasing my sensor.