I didn't have A/C either anytime the DSC was messing with the CAN network (anytime the car was at operating temp).

I had CheapABS do the rebuild. I overnighted it and pad for overnight return and was still under $200.

I really feel like the DSC module is the nexus of many STRANGE failures seen in these cars...

'That's what happen when you let system engineers design architectural system and not real Brick and Mortar Architects.

:bustingup

I always thought that even if the battery died in the key, you could still unlock the X by putting the key in the lock. Or am I missing something???

The door lock cylinders are known to fail in these cars so it's possible it's a mechanical issue if the lock just spins when you turn it.

My E53 just came up with these symptoms and I fear the ABS module (already fixed once) is now a terminal case. INPA indicates the CANbus is down. ISTA can't ID the car.

QUESTION: Assuming that the ABS module is indeed to blame, if I unplug the ABS module, at least the CANbus should come back up? Or will the disconnection of the ABS module also interrupt the bus lines? I.e. is this a daisy chain system or can it live with one of the CAN interfaces unplugged?

There has been a pretty good picture of the can bus posted somewhere on here. AFAIK the physical bus is not daisy chained but the data flow can be. One module might be depended on passing information to another so you possibly could loose the information from more than 1 module by disconnecting only one. Disconnecting should still give you your answer though on which module is pulling down the bus.

Hi Folks- This posting somehow found me after a few years. People have driven their cars with the ABS module removed with no other problems than a loss of ABS/DSC/etc so it (at least) has to be connected in a star configuration and not daisy chained. I would definitely try to disconnect it, power down and hope whatever is wrong clears when the car powers up... good luck!

Thanks all for responding. If I find some time this weekend I’ll remove the abs plug and see if the bus comes back up. Never a dull when owning a BMW....

Solved, replaced ABS module and coded to the car.
 

Sent the module for a warranty fix but in the end they could not get it to work. Got it returned and then sent it to Ebay seller "modulerepair" and he said the CPU had some fault codes frozen in it. He sent me a replacement and I installed it today, however still had to code the VIN number to get the module to work with the car.......

With NCSExpert no problem to do a Write-FGNR and SG-Kodieren but the trifecta refused to go away. After reading on various boards about the problem for an hour I decided to unleash NCSE on it once more. Then went to INPA and deleted the codes in the ABS module and the ones under Steering Angle Sensor. After that opened ISTA/D and found the calibration sequence for the SAS. Once I completed the procedure in ISTA the lights promptly extinguished.

Put the headlight and bumper back, went for a test drive and all is WELL!!

In some cases people report the DSC light goes away after coding the VIN nr and the other lights after the SAS is re-calibrated. In my case I had to reset the SAS before it would release the warning lights.

What a nightmare, amazing you figured all that out! Great job :2thumbs: