Help needed with ABS Problems
 

I was washing my oil covered 4.4 engine yesterday, (so much oil everywhere, it was impossible to see where it was coming from, and the valve cover gaskets are new and don't appear to be leaking.) Even though most of my spray was directed towards the lower front of the engine, I apparently caused a problem with the ABS, perhaps some water got somewhere it shouldn't be.

I do have the ABS/DSC/Brake trio of lights on. When hooked to my friend's Autologic, if I clear the faults, they come right back as soon as the car moves. The fault that is showing up as "15 ABS Return Pump"

Also, when checking the ABS system with the Autologic, both the ABS Return Pump AND the Pre Charging pump show as "OFF" and it does not appear that they can be activated, (although the Autologic can activate every device on the car, I'm not sure this is one you would hear or see a reaction, of if the normal state is supposed to change to "ON" when activated. If you have the Autologic turn on the windshield wipers...you KNOW the wipers are on.)

I tend to not believe in coincidences when it comes to auto repair. It IS possible this failure was just a coincidence, and had nothing to do with my cleaning of the engine. But I would bet I got water somewhere bad.

My next step will be to remove the big connector to the ABS module and air dry everything and spay some contact cleaner. Then put the connector back on, and hook it to the Autologic again. Anything else I should look for or try????

If you have the Bosch 5.7 which you do, I would probably send it to BBA-Reman for a rebuild, as they tend to throw intermittent "trifecta" lights.

$95

BMW Bosch 5 7 ABS Module Repair Service | eBay

Thanks for the reply.

So you think the module is bad? I had a bad module on my 2000 528i...same trio of lights, but unlike this one, I could not communicate with it at all with the Autologic. I did have it rebuilt with excellent result, (it DID have to be re-coded with the Autologic.)

At 95 bucks I would preventatively have it rebuilt since it's the same module from your E39.

However, I can't be certain that it is related to the problems you are having now.

I don't think much of coincidences either. If you can get it somewhere that is above freezing it might dry out and be fine once the codes are cleared. If the oil got somewhere it shouldn't have you will need to clean it off. I have used MAF cleaner to dry out and/or remove grease or oil from an electrical connection--it leaves no residue.

I would check and clean any associated electrical connections to see if that takes care of the issue first.

Dried everything out, removed and cleaned the main ABS module connector with contact cleaner. Cleared the codes, and after driving about 10ft the ABS Return Pump fault returns. Any ideas???

Would be nice if it was just a wheel sensor but I think it is time to test the ABS pump to see if it will run. You can do that by connecting 12v directly to the pump.

Have you cycled the ABS module with each bi-yearly brake fluid change?

Unfortunately, no. I bought it used about a year ago, so have no idea of its service history. And have not had a chance to do this myself either...too many other repairs keeping me busy.

Can you suggest exactly where to apply 12v? And what will it do if working properly?

I know if can be activated with the Autologic, and I tried that...nothing happened.

If PO didn't do proper flushes it would not hurt getting the module rebuilt. I would drain/flush/refill EVERY fluid soon.

No, I would check the connector with meter to find the positive pin.

I'm a little confused here. There is the big multi-pin connector which connects to the ABS module, then there is a smaller electrical connector on the top rear of ABS pump.

The connector on the back of the pump is the one you want to test. Test the female side for voltage and then connect the 12volts to the corresponding pin.

Should that female connector have voltage all the time when the car is on, or only when the ABS is activated by the Autologic?

Check it with key on. The pump should run if you are supplying current directly to it.

I get that, but should there be power on the female side of that plug at all times?

That ABS pump should not be running at all times should it? Or only when called for by the computer?

There should be no power to the female side of connector unless module is bad.

The ABS pump does not run all the time. If it does there is a module issue.

Well, I started by removing the ABS module, and what I found was definitely not good. The was about 1/2" of moist white crap at the bottom of the module. There was a good deal of this substance, and it was a bit gritty. So I cleaned it out, and sent it out to get rebuilt. When it returns, and it gets re-coded, I'll see if I still have a problem with the pump. Here's a photo to give you an idea how bad this thing looked inside:

http://i443.photobucket.com/albums/q...psf3bf679b.jpg

I mean, WTF was BMW thinking when the came up with the location for this module? Couldn't they find a spot that was not prone to get road spray?

Looks like you found the problem,