2002 E39 ASC BRAKE ABS lights on => Diagnostic Procedure & Parts Location

Thanks for all the advice.

My ABS/DSC/brake lights go on quite a bit less often than they used to after replacing the rear sensors. So I suspect that there's a problem with one of the front sensors, too.

I pulled them today and cleaned them, one had quite a bit of junk on it. Hopefully that will solve the problem, but only time will tell. Both front sensors tested fine with the DVM.

If it still recurs, I may try to find someone local (Pasadena, CA, in case anyone has a recommendation) to run a diagnostic on it.

Julie

Originally Posted by RobV15

Bluebee, has you problem been resolved?

Yes. My sensors all tested good so, for $150 (includes shipping), I had my ABS module rebuilt. Everyone told me to do that but it took my thick brain a year to come to the reluctant conclusion that you just can't easily TEST the ABS to prove it's the culprit.

Basically, if you have the 3-light (brake abs dsc) trifecta, and if your 4 sensors test good from the engine compartment ABS connector, then send your ABS module out to BBA or MM or ATE (highest to lowest recommendation) to be rebuilt (or buy a rebuilt or new module and recode).

The problem is simple. Apparently one steel-alloy power wire falls off its gold bondpad inside the sealed unit. If you're intrepid enough, you have a 25% chance of fixing the ABS yourself, for free.

Otherwise, BBA/MM/ATE will give you a 50% chance they'll fix it.
The last 25% get their ABS trifecta resolved with a new or rebuilt recoded unit.

So for a total cost of free (25%), $150-$200 (50%), or $500 (25%), everyone (100%) finally resolves their ABS broken-wire problem!

If you wish to repair the ABS yourself, for free, this thread is a must read.
We need MORE people like 540iMan, with the courage to repair their own ABS modules and report back to us how they did it so we can hone the open-heart-surgery procedure.

This recent thread has some excellent pictures of the front & rear sensors and discusses an ABS problem due to wrong-sized tires ...

Based on the 540iman encapsulation thread, it's looking more and more like there's a single final-assembly resistance-welded steel wire that breaks off its bond pad which causes a majority of the ABS failures we're sending off to the rebuilders to reattach (at about $150 to $200 each).

Notwithstanding the general recommendation of BBA/MM/ATE (in that order) to rebuild your Bosch 5.7 ABS control module, does anyone have insight on using these $99 cheap-abs guys to repair their BMW E39 ABS module?

While I was searching for terms I didn't know (for the all-inclusive BMW definitions list), I ran into this nice ABS thread covering the removal of the ABS control module from the car.

So I add this as an additional link to this one-stop-shopping cross reference.

I have the DSC warning/yellow triangle light ONLY...
My indy is telling me that the Precharge pump is defective...$1552.00 plus labor to replace !!!
Does anyone have any knowledge as to ability to prove that it is the pump ??
I dont see many posts where anyone has had to replace this 'very' expensive part... mostly a sensor or send
Computer off for overhaul.
So, does anyone know anything more about the Precharge pump on the 2003 E39 DSC system.
It is different than the 1997 thru 2002 ASC system.

Well, I finally got around to experimenting with what might remove the circuit board "goo" from the ABS module and my very unfortunate answer is "nothing most people might have in their garage". I soaked the entire, opened module in the following: Acetone, paint spray gun cleaner, gasoline, and 70% Isopropyl alcohol and none removed it. The good news is that any of them will loosen the goo from the board, but none actually did what I hoped it would do which was virtually melt it away such that no mechanical action would be needed to fully remove it and fully expose clean surfaces to solder to. These solvents made the goo runny and of much easier consistency to remove with possibly a small paint brush and careful brushing, but I hoped it would melt the goo like ice cream-ain't going to happen.. If one is determined to attempt a repair on the board, soak it in alcohol over-night and then take a small hobby paint brush and remove just what you want to repair being very, very careful around any of the micro-fine gold wires. I suggest BBA rebuild service or new. I believe you may be very lucky and find the correct wire and repair it with a liquid conductive material, but you also have a good chance of ruining your module permanently and to the point where I don't believe BBA may even attempt to repair. I could be wrong, but I am purely speculating that BBA has perfected the test jig to possibly isolate the offending wire and a way to carefully melt away the goo allowing access to just the heavy wire that is the offender. I will guess that if BBA were to find an otherwise repairable module where a DIY'er has attempted their own repair and torn or damaged one or more of the fine gold wires that they will pronounce it unrepairable and return. On a Bosch 5.7, I believe this module is so difficult to DIY repair I would not even attempt. If you send to BBAfirst, you will never need to wonder..

Bill

well I got my ABS module repaired from CHEAP-ABS.com But the lights still remained. They said after the repair it bench tested fine. I hate this. He told me that in some cases the codes have to be cleared but from all the threads I read about ABS failures the lights turn off by itself. Huge headache!

Originally Posted by repandpresent

well I got my ABS module repaired from CHEAP-ABS.com But the lights still remained. They said after the repair it bench tested fine. I hate this. He told me that in some cases the codes have to be cleared but from all the threads I read about ABS failures the lights turn off by itself. Huge headache!

You are not the first person to have this specific issue using ATE. ATE may tell you that they perform this test, but I don't see how they can. BBA does three (3) specific tests which I'm sure others will chime in after and say "we do too", but the results from BBA speak for themselves just as the results from ATE speak for themselves. ATE has successfully fixed many modules for people here. Take your chances. They are NOT that much cheaper as BBA does Ebay auctions as well. BBA customer service is FAR superior.

BBA tests:
1)Communication with module
2)bench test module controlling a motor with varying inputs testing all input signals to see response from the module.
3) BBA verifies the LIGHTS ARE EXTINGUISHED on your dash. Seems like a simple test, but they verify that your module is not outputting whatever latched signal that turns your three lights on. When you get a module back from BBA, no reset will be necessary. None should be anyway. This is a famous ATE stall tactic.

Now, your car could still have a problem, but it shouldn't be your module! The module is the problem the over-whelming percentage of the time, but not 100%. This is why you need to at least do a quick sensor test with a VOM. This has been addressed ad nauseum. You still need a scan and then depending on what it tells you, a VOM test. I received a "repaired" module from ATE that the owner claims he tested himself as 100% working. BBA tested it as definitely BAD and did NOT try to sell me anything. They refunded 100% of my money including shipping both ways!. A new module from Jared cured the problem. Now, you tell me whether ATE results are reliable???

Are Cheap-Abs.com and ATE from ebay the same company? It seems like you are mad at me haha. I didn't say cheap-abs.com was reliable. So far they have good customer service but if he tries to fix it again and it does not work I'm asking for a refund.

Originally Posted by 540iman

I soaked the entire, opened module in the following: Acetone, paint spray gun cleaner, gasoline, and 70% Isopropyl alcohol and none removed it.

Hi Bill,

I don't know how I missed this but the recent post brought me back to this thread where we're trying to compile all the relevant information about the ABS. Thanks for testing those solvents.

any of them will loosen the goo from the board

That's good to know ... it's progress...

none actually did what I hoped it would do which was virtually melt it away such that no mechanical action would be needed

The quest goes on to find what will dissolve the goop.

soak it in alcohol over-night

I'd be afraid the alcohol would "hurt" electrical components; are you?

BBA has perfected the test jig to possibly isolate the offending wire and a way to carefully melt away the goo allowing access to just the heavy wire

I don't doubt this one bit. They get $150 for fixing this one wire. They deserve it; but we should still continue our quest starting with the very next bad ABS module!

Originally Posted by repandpresent

Are Cheap-Abs.com and ATE from ebay the same company? It seems like you are mad at me haha. I didn't say cheap-abs.com was reliable. So far they have good customer service but if he tries to fix it again and it does not work I'm asking for a refund.

I'm sorry....I quoted YOU, but was actually responding to a PM sent to my private message box that was the exact same issue from a different individual. Sorry to hear others are having so-so results from another source as well... Seems like the number of sucessful repair shops 100% is dwindling. My bad. I was PM'd from a new member who sent their module to ATE and had it come back with a note that it was repaired and it was still throwing lights. I myself, had the same issue as you can tell. As far as ATE and Cheap-ABS being one in the same? No comment. Oh, not addressing my comments in any case to YOU personally so please don't take it that way in any case! My question was rhetorical.

Bluebee..I don't worry too much about alcohol ruining any components. Most electrical components can take contact cleaner and I would think rubbing alcohol would not hurt. In my case, the module was trashed so the point was moot. I guess I should put a disclaimer on my post that I was attemping to find a solvent that would dissolve the goo and any reaction by any of the components on the board should be considered at your own risk. The alcohol did not melt the goo anyway so I would say we are still looking for that elusive chemical that may melt the stuff away.

I have no idea how many wires BBA resolders or doesn't when they repair a module, but I would think that even if they isolate the bad connection, they likely do them all just in case. I think what we are all paying for is the R&D, the building, the techs, and the bench testing equipment. Who knows how many they get that they can't fix and they still have all the same handling and testing, but they do not collect a repair fee.

Originally Posted by 540iman

I would say we are still looking for that elusive chemical that may melt the stuff away

- alcohol (ethyl or isopropyl or other denatured alcohol methylated spirits)
- gasoline (or benzene, which is a similar naphthalene)
- turpentine (i.e., paint thinner made from pine tree resin)
- mineral spirits (paint thinner made from petroleum distillates, aka mineral spirits)
- acetone (or nail polish remover)
- xylene (aka Goof Off)
- trichloroethane
- butyl cellulose (e.g., EXPO whiteboard cleaner for dry erase surfaces)
- WD40, gunk, engine degreaser, brake cleaner, etc.
- ?

What else might dissolve the goo surrounding the Bosch 5.7 ABS control module circuit board's loosely tacked on problematic steel power wires?

bluebee,

I also have those three lights on about two days ago. The car drives same as previous. Can I just leave this on and keep driving until I have time to deal with it based on you summary? Just wondering how serious it is. Thanks.

Originally Posted by truelies

bluebee,

I also have those three lights on about two days ago. The car drives same as previous. Can I just leave this on and keep driving until I have time to deal with it based on you summary? Just wondering how serious it is. Thanks.

I was waiting for someone else to answer this ... but since nobody did, look at this quote below from the canonical thread on the ABS trifecta to find the answer.

Originally Posted by truelies

bluebee,

I also have those three lights on about two days ago. The car drives same as previous. Can I just leave this on and keep driving until I have time to deal with it based on you summary? Just wondering how serious it is. Thanks.

Understand a few things...You can drive the car as is for as long as you want so long as your odometer still works. That is because none of us knows for sure what happens if say you let it go for a year and rack up 15,000 miles on car and odometer stays where is is today. I know you can drive a month with no odometer, but letting it go "forever" could set the little light by your odometer indicating odometer discrepancy. If your odometer is still working, then you could drive it "forever" like this, but do not be fooled into thinking it "drives normal" it does not! You do not have ABS brakes anymore or stability control. As long as you don't get into a panic situation where you would need these functions to work to prevent injury, you are essentially correct in that it will feel normal. your tires will spin more taking off in wet weather.

Originally Posted by 540iman

none of us knows for sure what happens if say you let it go for a year and rack up 15,000 miles on car and odometer stays where is is today.

I always wondered about the odometer. Especially since mine quit working (predictably) when I removed the ABS control module from the vehicle for a rebuild.

As you said, nobody knows what happens if the "computers" get so screwed up that they begin to fail due to the conflicting information.

I do know that without the ABS control unit installed, the following score of items will occur:
- Brake/DSC/ABS trifecta solid yellow lights on (any combination possible when in the early stages)
- Service Engine Soon (SES) solid yellow light lit (on the cluster)
- No ABS
- No traction control
- No speedometer
- No odometer
- No tripmeter
- No cruise control
- Diagnostic trouble code DTC P0500
- No possibility of passing (California at least) smog inspections
- No automatic door locks (if set)
- No GPS (if you have navigation)
- No mileage calculations
- No fuel consumption calculations
- No range indications
- No speed-sensitive radio
- No speed-sensitive wipers
- Erratic fuel gauge (especially when near empty)
- Erratic transmission shifting (reputedly but I'm not sure why)

So you drove an other car when sent ABS to rebuild? How long did the rebuild take?

Originally Posted by bluebee

I always wondered about the odometer. Especially since mine quit working (predictably) when I removed the ABS control module from the vehicle for a rebuild.

As you said, nobody knows what happens if the "computers" get so screwed up that they begin to fail due to the conflicting information.

I do know that without the ABS control unit installed, the following score of items will occur:
- No ABS
- No traction control
- No speedometer
- No odometer
- No tripmeter
- No cruise control
- Brake/DSC/ABS trifecta lights plus SES light lit (on the cluster)
- Diagnostic trouble code DTC P0500
- No possibility of passing (California at least) smog inspections
- No automatic door locks (if set)
- No GPS (if you have navigation)
- No mileage calculations
- No fuel consumption calculations
- No range indications
- No speed-sensitive radio
- Erratic fuel gauge (especially when near empty)
- Erratic transmission shifting (reputedly ... I didn't experience this)

Originally Posted by truelies

So you drove an other car when sent ABS to rebuild? How long did the rebuild take?

Huh? I only have 1 car. I drove the bimmer sans an ABS (and all those other things I listed) while the ABS was sent to be rebuilt.

In fact, I drove for almost a year (about 12K miles) with the ABS/BRAKE/DSC triad lit on my cluster because it just went against my grain to send something out to be fixed that I hadn't yet "proven" to be bad.

With the Bosch 5.7 ABS control module, it's just one of those situations where you have to assume it's bad if the trifecta lights up and the four wheel-speed sensors test good.

The actual timing is detailed in the canonical ABS thread, but IIRC, it took a little more than a week (there was a shipping problem getting it to me as I had moved, plus it was near Christmas time).

When the ABS is on the car, the car can pass the emission test, is that correct? I need to do emission test next month.

I found BBA is an England company, so did you mail the ABS internationally to England?

Originally Posted by bluebee

Huh? I only have 1 car. I drove the bimmer sans an ABS (and all those other things I listed) while the ABS was sent to be rebuilt.

In fact, I drove for almost a year (about 12K miles) with the ABS/BRAKE/DSC triad lit on my cluster because it just went against my grain to send something out to be fixed that I hadn't yet "proven" to be bad.

With the Bosch 5.7 ABS control module, it's just one of those situations where you have to assume it's bad if the trifecta lights up and the four wheel-speed sensors test good.

The actual timing is detailed in the canonical ABS thread, but IIRC, it took a little more than a week (there was a shipping problem getting it to me as I had moved, plus it was near Christmas time).

Originally Posted by truelies

When the ABS is on the car, the car can pass the emission test, is that correct? I need to do emission test next month.

You're in Texas. I'm in California.
In California:
- The "smog" test also checks for "other things"
- You will fail the smog check with ANY warning lights on the cluster
- You will fail the smog check with ANY stored codes in the OBC
- You will fail the smog check if you clear the codes (recently)

So, in California, if your ABS isn't working or if it is out of the car, or (as I ruefully found out the hard way), even if everything is working fine just after an ABS rebuild but you haven't cleared the codes and driven enough miles for the OBC to be happy, you will fail the test (ask me how I know).

BBA is an England company, so did you mail the ABS internationally to England?

Nobody is gonna mail from the USA outside the USA. I used ATE and they're in some place smack in the middle of the USA. I don't remember where BBA, and MM are, but how to call them is in this canonical thread.

Just clear your error-or error history.

Thanks. I have three lights on, went to autozone no error code read. Is that possible ABS is defeated and no error code occurs?

Looks like Texas inspection doesn't care ABS light. I am not sure about BLK and DSC light since a lot of cars don't even have those.

Originally Posted by bluebee

You're in Texas. I'm in California.
In California:
- The "smog" test also checks for "other things"
- You will fail the smog check with ANY warning lights on the cluster
- You will fail the smog check with ANY stored codes in the OBC
- You will fail the smog check if you clear the codes (recently)

So, in California, if your ABS isn't working or if it is out of the car, or (as I ruefully found out the hard way), even if everything is working fine just after an ABS rebuild but you haven't cleared the codes and driven enough miles for the OBC to be happy, you will fail the test (ask me how I know).



Nobody is gonna mail from the USA outside the USA. I used ATE and they're in some place smack in the middle of the USA. I don't remember where BBA, and MM are, but how to call them is in this canonical thread.

Originally Posted by 540iman

Just clear your error-or error history.

Yes. I will do this after I arrive to inspection.

I've got the splended ABS, BRAKE and DSC lights illuminated accompanied by a P0500 speed sensor code.
My cruise control refuses to turn on. My odometer, speedometer, and trip meter all work.
2000 528i, 130k

On all 4 sensors I'm reading infinite resistance with + on pin(+) and I'm reading between 20M and 22M in the opposite direction.

The "diode" function DMM doesn't differentiate between either direction. It's not a meter problem, I tested it on a zener I had laying around.
I've removed the RR sensor from the car and get very similar resistance reading. Diode polarity is still 0 each way.

What are the odds that ALL FOUR of my wheel sensors have gone out?
If they did, then my odo systems wouldn't work, right?
Am I missing something?


Thanks