ABS Module Repair Info for E39 (from Volvo forum)

This is important info, so I thought I would share with all of you re DIY for ABS Module Repair!!! I already replied to another thread but will start this as a new thread.

I am going through this problem with my ABS Module in my 98 Volvo V70 now (ABS and TRACS lights are "On").

There are many places advertising a rebuild for $69-100 or so (ebay, module master.com etc and etc.). All they do is get your existing ABS Module, open it up and re-solder the broken joints and charge you $69-100 for a simple soldering job).

In the UK forum, the Volvo people have found the fix to be broken solder joints. You can fix yours if you know how to solder. The information below is for the 98 Volvo V70 but it must be similar for the 98 E39 (built by Bosch & ATE anyway).

The thread is here, if you have time read through the 7 pages of that thread, but basically very simple repair (Remove the ABS Module and re-solder the broken joints then re-install the ABS Module):

http://www.volvoforums.org.uk/showthread.php?t=7414

The relevant picture is attached below:

If anyone is doing the DIY re-soldering for the BMW E39, please post pictures!
(I got my Torx E5 sockets for my Volvo ABS Module from Harbor Freights dot com)

Save yourself $700!!!

cn90
98 bmw 528i
98 Volvo V70

Thanks for the info... If anyone is willing to try this out, let us know!

I sent mine to Module Master. Been working 100% ever since, and I'm backed by a 5 year guarantee. Open up your BMW module and you'll be surprised. Some of the connections need to be resoldered under a microscope. Good luck is all I can say!

From the Volvo fourms, the soldering was done using the naked eye....
No microscope needed.

Does anyone have a picture of E39 ABS Module Inside Anatomy?

Well,

The Volvo people were correct, I took my 98 Volvo V70 ABS Module out, it was tough to open the case but I did.

No obvious dry joints or broken circuits but I re-soldered all the joints in the picture using a magnifying glass (this is a must-have) and voila...No MORE ABS/TRACS light! ...

Saved $600 at dealer!!!

While I do not know the E39 ABS Module but from looking at it, it is the same principle, made by BOSCH ATE (like Volvo)...so if the E39 ABS Module goes wrong, you guys can "borrow" the tips from Volvo for the fix.

Hm i went for it and i think i lost.

BMW e39 520 early 2000, replacement module.

Pictures illustrate process.





High resolution pictures.
http://conventory.dk/bmw/bmw.zip

I tried to solder point large enough forme to hit.
However ChopperDoctor was right there are approx 10 connecting wires max 1 hair thick and approx 20 that are 0,5-1 mm thick., that i knew i could solder right. They are soo small they are hardly visible on the picture.

My result: im giving in and getting a time at a dealer to get i fixed, well knowing it will cost me half of the cars value.

History:

Possible trigger brake fluid changed to racing type.

Failure type both dcs and abs light on either from start or while running. not consistent.

failed occasionally
changed front sensors

still failed
shop changed rear sensors. + discs and fluid.

worked approx 3 weeks, then went into safe mode = 20-30 km pr hour.

DSC computer refurbed
still failed

left tire assembly changed(bearing, bearing house etc).
worked for approx 1 month.

final step ... i hacked replacement ecu into pieces.

The test computer typically stated error on at least two sensors, and the dcs computer.

Failure types along the way(while dcs indicated error):

cruisecontrol failed some times.
Speedometer failed in a period, started working without any changes.
engine went into safe mode.
Radio volume racing up and down.

the weird thing about this car is that the error continues to move around and it isnt stable. sometimes it works (hot or cold), sometimes not.

WARNING:
If lights are intermitant as mine you may end up in a situation, where abs will not accept full brake force. It will start to override(pedal vibration) you at approx 25% brake load. luckily it will disengange completly in approx 1-2 seconds. Problem is you never know when this happens and you may need 100% brake when pedal is pressed.

I will report back what had to be changed to get it to work. Im fearing that this car has severe electrical issues, as my rear bulb indicator is on, but the bulbs are fine. the cigar plug doesnt work either, but fuse is good.

Sounds like a classic wheel speed sensor issue; if your hubs are rusty this will explain the persistent issue despite replacing the sensors. OTOH, my grandfather's car had the sensors go which were rapidly followed by the module.

Rear light bulbs need to be the right material for the base; copper or brass will trigger the light; the system relies on the resistance of the bulb to determine whether it needs resisting.

Very interesting autopsy of the ABS module! Thanks!

One question: I want to take mine apart but I'm scared once I take it apart, that the rebuilders won't take it to rebuild (if I can't fix it myself with resoldering).

How did you open the ABS module?
Do you think the rebuilders will take an open ABS module?

Originally Posted by bluebee

Very interesting autopsy of the ABS module! Thanks!

One question: I want to take mine apart but I'm scared once I take it apart, that the rebuilders won't take it to rebuild (if I can't fix it myself with resoldering).

How did you open the ABS module?
Do you think the rebuilders will take an open ABS module?

do you have more pics of the speed sensor repair if u do i would be so happy cause i need to replace mine please, i made a thead asking how but no one responded.

Originally Posted by bluebmw83

do you have more pics of the speed sensor repair

I'm not an expert but I did read (almost) everything I could find on the topic of E39 ABS repair - and I don't recall (offhand) anyone actually "repairing" the speed sensor.

Sure they "tested" the 4 sensors; and they cleaned the sensors of greasy cruft; and they cleaned and secured the wiring connectors; but, I don't think I saw anyone actually "repair" the speed sensor.

The "repair" is to replace them (two 4 mm allen bolts for each front-wheel sensor and one 4 mm allen bolt for the rear sensors).

It's essentially impossible to repair the sensor due to several reasons.

bluebee, chances are that the reman guys won't take the module, or if they do, may charge extra for your fiddling around with it

Reminds me of a price list I saw a while ago: (paraphrased)

Hourly rate per hour

If your wife brings it in untouched: $10
If you bring it in and watch as I fix it: $20
If your wife brings it in after you've "fixed" it: $30
If you bring it in after you've "fixed" it: $40
If you "help" me fix it: $100

Post removed...

Originally Posted by bmw_n00b13

chances are that the reman guys won't take the module, or if they do, may charge extra for your fiddling around with it

I understand. That's my main worry about taking it apart.

I so very much want to satisfy my curiosity as to what's inside the ABS module ... but I give myself a 10% chance of actually fixing it by resoldering (those solder dots look awfully tiny in the pictures in this thread) ... so there's a 90% chance I'll be sending it out to the remanufacturer afterward.

If I were the reman, I wouldn't take an open unit (as your joke showed).

bluebee,

Here is the internal anatomy if you want to see:
http://bmwdriver.org/2008/12/16/e39-abs-module-repair/

I was not able to open i "nicely".

I ended up dremeling my way through.

I used a dremmel bit that looks a bit like the one the dentist uses. it like a little round head on a drill., will try to get a picture of it.

I used it along the ridge, close as you can see on the picture.

If you notice on the picture CN90 links to, its not opened up close to the connector.

This is because its hard to cut this side of the box.

I have found black silicone that will accept temperatures upto 300degress. i have used it to seal to box again.

I dont think that the rebuilder will be all that happy that you have opened the box. i expect that they will ship you another fixed abs box rather than the one you have sent in. But im not sure.

The price of a new abs module has decreased somewhat its down to approx 700eur.

-------

At present i have purchased yet another sensor, and a new abs module, a bimmer scan to encode the new module(warning mine wouldnt code the damn module). working on getting new scanner and software, that will do this.

Before changing the sensor i had a sensor fault on my front right wheel. (hub, sensor, bearing etc has been changed on this wheel).
After changing it, it read wrong gear at one wheel. suspect that either i have the wrong sensor, or they have changed the hub to a wrong version.

At present i wish i had just dumped the car at the dealer and let them fix it. i have put in more than they would charge.

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Does any one know how to measure/check the wheel sensor without a scanner ?
and does anyone know a scanner that will read live data from the abs module and let me code it to a new abs module ?

You need a GT1 to code those items, I believe. You can get pirated ones on eBay for like $2k.

ABS Modules are about USD550ish….

For the record, an ABS control module autopsy is here ...

Thank you very much for this thread. I finally got my x5 back on the road after a nightmare with one of the vendors claiming to repair ABS modules. I got 3 different units from them, none worked, and they stiffed me on my refund. I finally ended up getting a new module from the dealership for $900. I'm sure there are companies out there that can fix these modules but autoecu is just not one of them. Please use extreme caution if you choose them.

If you would like more detail on this please feel free to email me.

Chuck

Thanks for the tip I will avoid them.