ASC/ABS module not communicating

[agent851]

After winter hibernation (on battery tender) I wanted to have a spin in my z4. But upon starting, I was greeted by bunch of lights on the dash, all related with braking system.
Connected the laptop, did a scan of the car, and lots of modules were complaining that they are not able to communicate with ABS module.
Check the fuses behind glove box, in engine bay - all fine. Have not seen any rodent marks upon quick visual inspection. Tried disconnecting the battery, and reseating abs module plug.

Disconnected the battery, for now, to check next day, if it will magically fix it self.

Is abs control unit toast? Maybe someone else had such experience?

 

[srhutch]

I had to replace mine due to communication lost around 4 years ago. Depending on you exact model will depend if a new (used) one will cost £100 or £600.

 

[agent851]

Got replacement ABS module, swaped "brain" part over to my old unit, so to avoid bleeding.

Now i get communication, updated VIN on replacement module using P.A. soft bmw scanner. Cleared all dtc's.
But 3 errors can't be cleared. 5DD2 (inlet valve calibaration data fail), 5DD0 (Valve calibration data fail), and 5E1F (PT-can chassis number wrong / ecu not initialized).

I tried using ista to calibrate dsc, and it fails at last step suggesting, that theres leak in system, or that it needs bleeding, but pedal feels firm as it should. Will be doing full bleed on system.

 

[agent851]

So I changed the hydraulic part, to match electric part that it was paired to originally, bled the system. Activating bleeding procedures over inpa seem to operate correctly. Brake pedal feels ok, when holding it under pressure for a while, nothing leaks and it does not sink to the floor.
Indirect tyre pressure monitor also works.

But it still would not initialize, and warning lights stay on.:headbang:
Any tips would be greatly appreciated

 

[srhutch]

If you’ve changed the electrical part, the VIN will need to be coded into the unit before you can do anything. Would need to dig out what I used but from memory it was system32 to change the VIN.

 

[agent851]

Any chance there's a guide for that somewhere? I only find ident_vin_schreiben and after providing the vin with cheksum, job status is "ERROR_ECU_SUBFUNCTION_NOT_SUPPORTED__INVALID_FORMAT"

 

[agent851]

Found what i was doing wrong.

I selected dsc_mk60.prg in tool32. While I needed dsc_85.prg. After selecting correct prg file I was able to code in the vin. That removed 5E1F error.
After running initialization procedure that was suggested by ISTA both 5DD0 and 5DD2 were removed - no longer there was a leak, or air pocket (there wasn't in first place).

Lesson learned - don't use pa soft for more advanced tasks.

Thanks @srhutch for leading down the right path.
Also I found German forum useful https://www.motor-talk.de/forum/dsc-steuergeraet-nach-austausch-codieren-vin-t7173578.html