ABS problems drives me crazy

[Piri]

523i 1997 december
ABS ASC light sometimes on when riding over a bump
It was for months Now constantly on. Plugged in said left front sensor
Replaced left front sensor Light still on said right front sensor
Replaced right front sensor light still on Said ABS ASC motor
Replaced main hydro unit with motor
Light off but car is not driveable When you take off no power when you switch off ASC everything OK but ABS/ASC light back
Plugged in and Launch tester see that front wheels are not turning
back speed OK front speed 0
Replaced front sensors again to OEM Hella sensors
Problem not solved Swapped ECU under glovebox making no difference
ABS 5.0 system pre facelift

[kaineb]

Usually when you get multiple wheel speed sensor failures and electrical oddities it is the microprocessor controller attached to the front of the pump housing. Very common failure on these cars. Many threads about it. This will need to be coded to your car if replaced with new or used. There is a chance that it can be repaired. There is a company out there that can repair some versions of these controllers. Try searching google for bmw abs repair.

Good luck!

[Piri]

there is no controller on the front This is the older ABS 5.0 version
controller is under glovebox Both units replaced and problem still exists

[Piri]

http://www.realoem.com/bmw/showparts.do?model=DH42&mospid=47554&btnr=34_0524&hg=34&fg=20

[Piri]

1 and 7 was replaced

[wjennings]

If this happens more while braking, make sure your suspension bushings and shocks are in good shape. The difference in wheel speed when going over bumps may trigger a fault code when there is nothing wrong. If the car has sensor wheels, are they clean and free of corrosion? Check these things out before you spend more money. Hope this helps. :)

[Piri]

No this is electrical problem no suspension related

[papado]

Use no abs.... its more fun.... :P

[Piri]

It seems to be no front sensors are working
I have tried 2 different brand new but not working
Wiring is OK
It is strange that rear sensors mesured 3,09 kOhm but front (grey) ones no resistance!4
Can anybody confirm that front wheel speed sensors has no resistance ? Pre facelift 1997 december grey ones

[Piri]

I have connected INPA and get error : 76 CAN DDE message error error counts 225

[Piri]

Can you help me on this message please

[Aussie528iT]

I would think that all ABS sensors should read the same. If there is zero resistance then you have a short circuit somewhere. If there is infinite resistance then an open circuit somewhere. Since they are both showing the same readings then the problem would most likely be in some common component. ABS module, wiring, connector, poor earth etc.
Only use genuine ABS sensors. Those who have tried after market ones don't allways have success.
The INPA error seems a little odd. As far as I know DDE is a diesel engine DME and you have a petrol engine.??? The error counts are the number of times the error has occured. The error seems to indicate that the DDE/DME isn't able to send or receive messages over the CAN bus (Controller Area Network Bus)
Check all the other units on the CAN bus for errors. Kombi, ABS, EGS (autotansmission if you have one) If they show similar errors on other units bar one then the one without the errors is the problem. The other units can't communicate with it, hence the errors.
When you replaced the ABS control module was it coded to the car? The only time you don't have to code a module is if it is off an identical car. To code it you need NCS (NewCoding System) software. This may or may not come as part of the Ediabas/INPA software, depending on your source.
Edit: A bit more info.
You can test each ABS sensor on the car by jacking up each wheel in turn and spin the wheel whilst at the same time looking at wheel speed live data received by the ABS module using INPA.

Don't know if this may help but?????

Regards
RonR

[Piri]

I still have the problem no one could help me since.
I desperately need to repair this car
thanks

bump

[Piri]

problem solved
The front wheel bearings caused the problem -:))

[BlackCloud]

Glad you are up and running!!