Have any knowledge of e39 abs modules?.. I've got some questions.

[noE30]

In my never ending search of trying to find a daily I have found a e39 that I am interested in. Its a 2001 525I, dark green, tan leather, just over 100k miles, auto, no rust super clean car. Its currently got the abs, service engine soon, and traction control lights on, also the odometer and speedo do not work. The owner asked me if I had any idea what it could be and my first thought was a speed sensor of some sort, but after some research it seems the abs module is a common issue and will cause all of those cluster issues. I'm just wondering if anyone you have e39s and have had to deal with this issue or if you have any ideas about how to go about fixing it? I've read that you can send the module out to be rebuilt and that usually fixes it, I just don't know if I should try buy the car knowing it has an issue. I may be able to use the issue as leverage to lower the price, that is if I can get it fixed.
So what say you r3v? Anybody have any input?
Thanks

[kway]

Yes, it's most likely the module, but it could be just a wheel speed sensor. The odo/speedo reads off the right rear I believe. Then you get a check engine light because the ECU gets pissed when it doesn't get a reading on road speed.

The only way to rule out the module is to have someone plug in to the car and see if you have communication with it. It's easy to change, only 6 screws, but it has to be coded afterwards, which you'll need to do with BMW specific diagnostic equipment, GT-1, autologic, etc.

The last one I did needed a module, then once I was able to communicate and read out fault codes, found out it needed rear wheel speed sensors also.

It wouldn't keep me from buying the car, but it can get expensive.

[noE30]

Well the owner has told me that he and someone else both looked into and had the codes read (neither of these guys know anything about bmws) I talked to them both last night and they were convinced that it was the module. What's odd is that I read that if the module fails then it can fuck up your speed sensors so both would need to be replaced, the owner says the sensors are fine so I'm guessing maybe the the module hasn't ruined the sensor yet... ?

[mikeedler]

if the speedo isnt working it usually is the left rear sensor that is bad. If that sensor is bad, alot of times the faults can't be read out an the module wont respond when trying to read out the faults. It is also the sensor that the speed is read out from for the speedo.

The ABS modules do go bad kinda often, and are about 800 euros over here. there are a few places that repair them over here for a few hundred- easy to replace, sensors, not so easy when they are corroded in there.

[noE30]

Good to know. I might try text drive the car again and take it to get the codes scan again so I caan see it for myself. I'm not too worried about it. The car is real nice so I might try to see what kind of deal I can make with him this coming week.
Thanks

[bimmer630]

A bad module wont damage the sensors. Its usually either a bad sensor or a bad module, never both. shops just end up doing both because they read a fault for a wheel speed sensor and just replace it without testing it, and they theyre like shit now it needs a module too.

I used to run jumper wires over from one sensor to connector for the other side and run the car on the lift and see if the fault then changes to the other side, if it does, its a sensor, if it doesnt, its the module.

also at the dealer we kept a batch of faulty units in a drawer with their malfuntions written on them, to use for diagnosis of sensors etc

[mikeedler]

yeah, it's common practice for us to just plug in the new sensor and see if the fault can be erased before it is installed.