E39 ABS Module?

[Lucan 196]

Recently my ABS/DSC and periodically trans light (goes into limp mode) turned on, I got a friend to check it out with his diagnostics software, I accidentally cleared the error history instead of reading it the first time round though -__-

I was hoping for a wheel speed sensor or something easily fixable/replaced to be the cause but all looked normal after running the car around a while...besides the dash lights.

The ABS Module is a common problem in E39's, so I decided to pull it out and have a look.

Does this look normal?

The goo appears to have either never been there or burnt away...

Wires are all still attached

[hotwire 352]

No it doesn't look normal. Whether or not that is the problem though is another thing.

You cannot always go by the fault codes that are logged, I have seen many times where they have written a book of codes & all are bullshit. It is the unit that has been the fault. Conversely I had mine where initially randomly, & then frequently, the lights would come on, the speedo would stop. Scanning it - showed no fault codes. With fault present, current data would show R/H rear sensor dead. Smelling a rat, I monitored the RHR sensor out of the module & confirmed when the fault was present the module output voltage to the sensor was dead - a faulty module!

I have found that a good percentage of units are repairable, but some, as mine did, prove not able to be.

[HELLBM 1531]

Can do a replacement.

[Allanw 1052]

I've never opened one, but does NOT look normal - Looks like a previous repair to me! That's hand soldered connections, not factory done.

I recently had the Christmas tree lights too (ABS/DSC/traction) a few times a week. Codes showed voltage issue with right rear, and left rear on different occasions. The indicators stopped working ONE time, and were fine ever since. This was about 3 weeks ago.

I installed a brand new ignition switch (cos they're actually really crappy and cause a LOT of weird issues) and have had no problems for the last 3 weeks

Hopefully it stays that way! I thought I was going to be up for a new module too. I have since fitted a heatsheild beside the module (before problems would be sensible ), but I don't know if it will help or not - the abs still gets REALLY hot, because when you're stopped, the whole engine bay stays hot.

Anyway - keep us up to date with how it goes.

[hotwire 352]

Yep, looks to me like it has been previously played with too. That is one place they often fail. That said the OP will know as you literally have to break into them the first time, then silicon or similar to close them again. There is always a tell tail sign.

Been there too with the ign switch on mine - weird happenings - no monitor, airbag light partially on. Turned out intermittent voltage drop on acc output. Because I could be bothered, & I didn't have a replacement on hand, I pulled mine apart & cleaned the contacts - all good There was no real wear on them

Edit, I wouldn't hold my breath for the ABS thing though

Edited November 30, 2013 by hotwire

[Lucan 196]

Had the car scanned again today:

[Lucan 196]

Yep, looks to me like it has been previously played with too. That is one place they often fail. That said the OP will know as you literally have to break into them the first time, then silicon or similar to close them again.

I actually had to dremel off what id say was the original sealant.

So unless you can strip out the guts from the opposite side I wouldn't know how someone else has got it there.

[hotwire 352]

^^^^ Ok but it certainly looks like that area has been repaired from the pic.

As I said in my first post - when the modules fail - they can write all sorts of incorrect faults, often external faults to the module (speed sensors, voltages etc) all red hearings.

That said - some of those faults listed are internal module faults. In any case that pic looks suspect

[Allanw 1052]

Edit, I wouldn't hold my breath for the ABS thing though

Shhhhhhhhh! I'm trying to think positively about it! It's one of those things I knew would happen one day anyway.

[hotwire 352]

Shhhhhhhhh! I'm trying to think positively about it! It's one of those things I knew would happen one day anyway.

Good on you. I was too until ours did the same, I had many people on my Nav data base contact me about this & asking advise & then.....

If you find you need a new unit - get hold of me

[Lucan 196]

So tonight I looked under a proper illuminated magnifying glass at the repair job

I cleaned up the flux mess and found the wire second from the left broken, not sure if the flux was holding it in place or if I snapped it but I've resoldered it and sealed her up.

Will report back tomorrow if this has sorted anything out.

Otherwise I'll be heading over to Ray for a replacement.

Edited December 2, 2013 by Lucan

[Allanw 1052]

Good luck!

At least I've seen inside one now!

[turbolizard 38]

I have similar symptoms with the three yellow lights coming on in the dash after the car is started. This was happening occasionally after the car was warm but now seems to happen almost immediately almost all the time. Nothing other than the lights coming on is noticeable as a problem.

If it is the module and it is replaced with a working one then I guess it needs to be coded to the car. Is this much work? Who can do it? Do I need to get the parameters out of the old one first?

[hotwire 352]

If it turns out to be the module - Prolly best to see if it can be fixed, a S/H unit that has not been touched will be on the verge of needing to be.

Powerstop Engineering in Tauranga will fix it if it is able to be.

Otherwise get hold of me - can sort new units

Yes a replacement module requires coding to the car - it talks to the instrument cluster. Easy enough with the right coding device. I just dropped mine into the friendly dealer to programme ...

Edit - no you don't need to get the parameters from the old unit - the replacement retrieves info from the cluster

Edited December 10, 2013 by hotwire