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

bluebee · Mar 2, 2008

PharoE39 said:
i am just afraid to put too much pressure and break something.

I think you need to just pull harder. But I realize that's easy for me to say.

Looking closer at the 1998 BMW 528i realoem diagram, it seems like you have 4 torx bolts plus one bottom bolt (as you already described).

What's DIFFERENT from my 2002 ABS (besides the 6 torx bolts) is that your hydraulic unit "appears" (to me) to be combined with the ABS module.

In my 2002 situation, the two units are connected but separate. It may be that your ABS module is integral with the hydro unit (someone with a 1998 can give you better advice than I can seem to find for you though).

If all else fails, call the phone numbers for ATE that I listed prior or BBA Reman or ModuleMasters and ask them how to remove it (they'll certainly know).

bluebee · Mar 2, 2008

Well, I'm gonna go back tomorrow and get my BMW smog'd again.

I didn't change anything. I'm sure the smog failure was a bogus California technicality (any good DIY needs to tell users don't smog your car directly after an ABS rebuild ... you need to clear the bogus P0500 code that happens when you remove the ABS module and then you must drive for at least a tank full of gas before taking the smog test it seems, in order to rebuild the 8 databanks back up).

1 Misfire
2 Fuel
3 Comp
4 Catlyst
5 Evap
6 Sec Air
7 02 Snsr
8 02 Htr

Here are California emission test results on 87 AKI Costco fuel:
15mph(2400rpm) --> Measured_C02=15.0%; Measured_02=0%
25mph(2400rpm) --> Measured_C02=15.0%; Measured_02=0%

15mph(2400rpm) --> Measured_Hydrocarbons=0PPM (MaxLimit=52, Avg=4)
25mph(2400rpm) --> Measured_Hydrocarbons=0PPM (MaxLimit=36, Avg=4)

15mph(2400rpm) --> Measured_CarbonMonoxide=0.0% (Max=.49, Avg=.01)
25mph(2400rpm) --> Measured_CarbonMonoxide=0.0% (Max=.46, Avg=.01)

15mph(2400rpm) --> Measured_NitrousOxides=21PPM (Max=424, Avg=16)
25mph(2400rpm) --> Measured_NitrousOxides=25PPM (Max=711, Avg=18)

I'm almost empty so I'll fill up on 91 AKI Costco just for the fun of an experiment to see if that changes the numbers any on the emissions side of the equation.

bluebee · Mar 2, 2008

Well, my 535i with the rebuilt ABS passed inspection!

That's proof both the invisible MIL and the P0500 failures were bogus and solely due to the temporal proximity of me removing and replacing the ABS control module.

However, every time I learn something, I end up with new enigmas!

The first time, I had driven the BMW only about 50 miles between replacing the ABS control module and getting the car smogged ... obviously that's not enough to clear the two bogus errors (invisible MIL & bogus P0500) ... so in the DIY, we should be able to tell others what to do properly if we can figure out what happened.

After failing the first smog check for the bogus P0500 code, I had all the codes cleared - but the mechanic told me it still will fail California smog because you can't pass if your codes are recently cleared or if your SES/MIL was recently reset. At the very least, you must drive a certain number of miles for the 8 codes to build themselves back up again.

So, I drove for a tank or two of gas (about two weeks transpired) and, retested today with the same mechanic w/o changing anything other than the grade of gas (for test purposes I did the smog on both 87 AKI and 91 AKI to see the results which were surprising but OT for this thread).

At my request, the same mechanic checked the codes first and said "oh oh ... it's gonna fail again" because there is STILL a "MIL" reported on his computer (it says MIL on his computer but w/o any codes visible). He asked if I wanted him to fix it or if he should proceed, cautioning me once he starts with the test, he has to finish it (and charge me full price). I told him "nothing was wrong with the car in the first place ... please proceed".

Well, after ten anxious minutes, it passed, even with the "invisible MIL" still indicated on his computer!

What happened? How do we prevent this for others in the future?

This is my hypothesis of what happened (please help answer questions).

SES/MIL:
- A visible SES lights when you remove your ABS module;
- When you replace the module, the visible SES stays lit;
- After (3?) ignition starts (and/or? 50?) miles; the visible SES goes out;
- But the "invisible" MIL remains (at least mine remained);
- This "invisible MIL" does NOT show up on the OBDII tester!
- This "invisible MIL" shows up on the California smog test as an undefined MIL with no codes associated with it;
- QUESTION: What is the proper way to clear the visible SES and the invisible MIL?

P0500/VEHICLE SPEED SENSOR MALFUNCTION:
- A bogus P0500 code occurs when you remove your ABS module;
- When you replace the module, the bogus P0500 remains;
- This bogus P0500 shows up on the OBDII tester;
- You can clear this bogus P0500 with the OBDII tester;
- QUESTION: Can you clear the bogus P0500 just by driving a certain number of miles?

bluebee · Mar 2, 2008

For comparison purposes, I opened up a separate thread on emissions comparison amongst us.

Est1974 · Jul 9, 2008

replace the ignition module. Then start trouble shooting.

Z4NL · Mar 1, 2010

bluebee said:
Q: Ok. Ok. Last question ... Do you think the ABS failure is a BMW design problem?
A: No. They say they get a LOT of Bosch 5.3 ABS modules from Audi, Saab, and VW in addition to Bosch 5.7 ABS modules from BMW.
They all fail. The problem, they say, is that Bosch uses cheap components.
They replace the cheap components with better quality components; they say that's why they give a lifetime guarantee.
They say they even replace components that test out as good but which have a history of failing.

Ik think this is BS. The components on the board are not the issue.

The ABS modules fail because of cracks in de soldered joints. This is due to years of heating up / vibrations / cooling down of the unit. I have basic electronics skills and resoldered all the joints / bridge wires of the unit under a microscope. Problem solved. Total repair time about an hour. Cost: about 1 cent worth of solder.

bluebee · Mar 2, 2008

Z4NL said:
ABS modules fail because of cracks in soldered joints. ... I ... resoldered ... under a microscope. Problem solved.

I didn't have the guts to open my ABS control module but now that I know that the $150 rebuilders will still take an opened ABS control module, I might recommend others attempt the repair themselves first.

BTW, I don't know if we ever saved the original Chris Parente ABS article from 2008 ... just in case it disappears if it's not yet in this thread, here it is.

Edgy36-39 · Jan 29, 2008

Thanks, Bluebee! Appreciate the plug, and unless Wordpress collapses the post won't go anywhere, so here's the link so my traffic stays up! :thumbup:

http://cparente.wordpress.com/2008/11/12/diy-the-answer-to-abs-problem/

e39vinay · Mar 10, 2010

Hi Guys...I really need some help here...well...my problem is that I don't have speedmeter and as strange as this might appear i don't have any ABS light on (unless i unplug the ABS module or wheel Sensor). OK...i have a BOSCH ABS 5.0 module...unlike most of you who have a 5.7 version. Made test on my clusters and everything work (all wipers work; Test 02)....anyway...now the strange thing is that....though my ABS module does not send any signal to tell me that any of my speed sensors are bad (no lights on cluster, unless i disconnect the ABS Wheel sensor; meaning they are properly connected)...but when i tried to test the sensor....(diaode test...all i can read is 1)...nothing else....I AM SURELY connecting the wires correctly...no results...i really want to have my speedometer and MPG wiper working again...so please guys help me. For those who want to understand the BOSCH ABS 5.0 Module here's some info:

The Bosch 5.0 uses a solenoid module which mounts to the hydraulic unit. The pump is hardwired to the module without a connector. The actual controller is located under the dash or beneath the rear seat.

THE MODULE:

Pin assignments at connector X1171

Pin Type Description / Signal type Connection /
Measuring notes
1 E Voltage supply, terminal 15 Terminal 30 voltage supply Fuse F17 DDE Fuse F31 DME
2 A Valve control Hydraulic unit, Left front inlet valve
Relay control
3 A Relay control Valve and motor relay
4 Not used
5 Not used
6 A Valve control Hydraulic unit, Right rear inlet valve
Relay control
7 A Relay control Motor relay
8 Not used
9 A Engine speed signal Left front wheel speed splice
10 A Engine speed sensor voltage supply Left front speed sensor
11 E Engine speed sensor signal Right rear speed sensor
12 A Engine speed sensor voltage supply Left rear speed sensor
13 E Engine speed sensor signal Left rear speed sensor
14 A Engine speed sensor voltage supply Right front speed sensor
15 E Engine speed sensor signal Right front speed sensor
16 Not used
17 Not used
18 A Increase idle speed signal Engine control module (DME)
19 E B+ power/feedback Engine control module relay, terminal 87
20 Not used
21 Not used
22 Not used
23 A Voltage control Auxiliary throttle position motor (ADS) DME
24 E Generator signal Generator control splice DME
25 A Valve control Hydraulic unit, Left rear outlet valve
26 A Valve control Hydraulic unit, Intake valve
27 A Valve control Hydraulic unit, Right front outlet valve
28 M Ground Ground point
29 M Ground Ground point
30 A ABS malfunction indicator lamp Instrument cluster
31 A ASC malfunction indicator lamp Instrument cluster
32 Not used
33 A Valve control Hydraulic unit, Left front outlet valve
34 A Valve control Hydraulic unit, Right rear outlet valve
35 E Engine speed sensor signal Left front speed sensor
36 A RH rear engine speed signal Transmission control module (AGS)
37 A Relay control Valve relay
38 A Engine speed sensor voltage supply Right rear speed sensor
39 M Component ground ASC throttle position sensor DME
40 A LH rear engine speed signal Left rear wheel speed splice
41 Not used
42 A RH front engine speed sensor Right front wheel speed splice
43 A Throttle position sensor voltage supply ASC throttle position sensor DME
44 E ASC passive sensor signal ASC/DSC switch
45 Not used
46 E/A Data link TXD Data link connector
47 Not used
48 E Brake signal Brake light switch
49 A Valve control Hydraulic unit, Changeover valve
50 Not used
51 E Throttle actuator terminal 30 voltage supply Fuse F8 DME
52 A Valve control Hydraulic unit, Left rear inlet valve
53 A Ground control Auxiliary throttle position motor (ADS) DME
54 A Valve control Hydraulic unit, Right front inlet valve
55 M Ground Ground point
56 Not used
57 Not used
58 Not used
59 Not used
60 Not used
61 E/A CAN-bus high Engine control module (DME)
62 Not used
63 E/A CAN-bus low Engine control module (DME)
64 Not used
65 Not used
66 Not used
67 E Throttle position sensor slider voltage ASC throttle position sensor DME
68 Not used
69 Not used
70 Not used
71 Not used
72 Not used
73 Not used
74 Not used
75 Not used
76 E Park brake signal Park brake switch
77 A Ignition timing signal Engine control module (DME)
78 Not used
79 Not used
80 Not used
81 A Ignition fade-out signal Engine control module (DME) DME
82 Not used
83 A Transmission influencing signal Transmission control module (AGS) DME
84 A Power Hydraulic unit DDE Hydraulic unit
85 Not used
86 Not used
87 Not used
88 E DKI signal Engine control module (DME) DME

Please help guys...btw....at Cluster the Speed Sensor wire is the brown/red wire (White connector 26 pins) found at pin 17.

Can anyone here provide some help??

jpheather · Apr 13, 2009

I have a 2001 525i wagon. I get the ABS/Brake/DSC lights on after the car warms up. Sent the module to Modulemasters, and they said it tested fine but showed a problem with the left rear sensor. Replaced both rear sensors (wire casing badly cracked) and still have the same problem.

Did the diode test and the left rear sensor reads OL with pin 13 positive/pin 29 negative, and also OL reversed. Other three sensors read about 1.9/OL for the pairs. (I checked multiple times and got the same readings for all 4 sensors, suggesting that multimeter operator error is not likely).

No problems with speedometer or cruise control when the lights are on.

Are there any likely causes of failure between the module and the rear left sensor that I should check out? Or any procedure for checking that?

Thanks,

Julie

bluebee · Mar 2, 2008

jpheather said:
Modulemasters said it tested fine but showed a problem with the left rear sensor.

For cross reference, experienced users are posting their results with ATE, MM, and BBA in this thread...

bluebee · Mar 2, 2008

bluebee said:
experienced users are posting their results with ATE, MM, and BBA

Unless there is some argument, if you're reading this thread to resolve your ABS/BRAKE/DSC trifecta, we (the royal we) recommend, in this order:

1. BBA
2. MM
3. ATE

Make your decision based on that, plus whatever other factors (e.g., price, warranty, etc.).

In addition, this thread has a nice short ABS front sensor replacement DIY.

bluebee · Mar 2, 2008

For the record ...

We're getting somewhere on the ABS autopsy and thin gold wire repair over in this related cross-linked thread titled "removing "snot-like" goo from ABS circuit board- Bluebee pls. read!"

Here's a quick summary of what I found doing some *****wire research:

http://forums.qrz.com/showthread.php?t=171525
- Used a stereo microscope to repair a Bosch 5.3 ABS control module
- Said the wires supplying power were broken
- Repaired two broken aluminum wirebonds with a 30 gauge copper jumper.
- One danger is the wirebond pad came off the board.
- "Just to make working on the board miserable, Bosch added a heavy gooey gel
- He says the factory uses ultrasonic bonding.
- The point of failure for these Al wires is on the gold contact side.
- Best to solder copper to the aluminum w/o removing the aluminum wires
- See picture at http://passat-b5.ru/remont/abs/11.jpg
- Recommends epoxy from Mouser Electronics P/N 590-8331-14G $23.95
- Russians recommend a special aluminum flux for soldering to copper.
- Recommend as a failsafe http://www.cheap-abs.com/ ($100 for Bosch 5.3)

http://www.bimmernut.com/forum/showthread.php?t=38384
- These guys also break the thin gold wires and they rue the gel
- They have a link to the Russian site, but, it's in Russian.

http://www.saabcentral.com/forums/showthread.php?t=179828
- These guys hacksawed off the cover of the ABS (they did not dremel it off)
- This is the second guy who said the power wires were the ones that broke
- Also used a microscope to see what he was doing
- They suggest http://www.lbak.dk/Audi/Repair_ABS_unit_passat.pdf
- They glued and nail varnished the results
- They say there's not much else on the board that can be fixed but wires
- They test it on the car, and then seal it up when it's working

http://www.automotiveforums.com/t577273-abs_control_module___repair___replacement_cost.html
- These guys used a knife and hammer to open the cover ...
- Recommend Silver Epoxy (silverglue, silverpaint, conductive paint)
- Also use chemically neutral glue or resin to stabilise the repaired spot.
- Warn not to use a soldering iron due to heat on the controller chip
- Also warn about bond pads coming up due to solder heat so don't use solder
- Remove as little gel as possible due to the propensity to break gold wires
- They test it on the car, and then seal it up when it's working
- Cover off: http://www.antiekeradio.nl/deeplinkimages/audi/abs/ABS1.jpg
- Broken wire: http://www.antiekeradio.nl/deeplinkimages/audi/abs/ABS2.jpg
- Silver epoxy: http://www.antiekeradio.nl/deeplinkimages/audi/abs/ABS3.jpg
- Sealing ABS http://www.antiekeradio.nl/deeplinkimages/audi/abs/ABS4.jpg
- User N3IDT http://forums.qrz.com/member.php?u=252575
- http://forums.qrz.com/showthread.php?t=171525
- Some russian guy running passat-b5.ru; http://passat-b5.ru/remont/abs/
- The two processor units are fed the same input, and process it in the
same way. The results are compared and only used if they match.
(i.e. if you break one or two wirebonds, the module throws an
'internal error' code and stops working)
- All valves are controlled by separate processors that can determine if
the valves are working or not (i.e., break a wire to the solenoid and
it throws an error and stops working)

http://forums.audiworld.com/showthread.php?p=15052859
- This guy also talks about the terrible goo
- He references http://forums.audiworld.com/a6/msgs/424238.phtml
- He used 0,1 mm wire and sealed with black silicone
- He also found the faulty wire to be the power wire

bluebee · Mar 2, 2008

Here are some ABS autopsy *****wire repair pics from our Russian Bosch ABS repair friends posted to http://passat-b5.ru/remont/abs/ and reposted here in case that site goes down ...

RobV15 · Apr 24, 2009

DEEP BREATH! WOW, great thread.
Bluebee, has you problem been resolved? Im currently trouble shooting the same problem as we speak. Hopefully I manage to get it fixed.

Great DIY by the way!

jpheather · Apr 13, 2009

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

bluebee · Mar 2, 2008

RobV15 said:
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.

bluebee · Mar 2, 2008

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

bluebee · Mar 2, 2008

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?

bluebee · Mar 2, 2008

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.

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

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