This is my first post on zroadster and hopefully it will save others from the pain I went through with this problem. This forum proved really useful when I was diagnosing my issue but I have some info not mentioned in the threads I found.
I had the dreaded ABS and ASC lights appear but it wasn’t due to the common issues mentioned on here a lot i.e. solder joints in pump-mounted ABS module or any of the wheel sensors. Long story short I have a 1998 2.8 Z3 with the ABS/ASCT module mounted under the glovebox, which seems to be more common on the E36 than the Z.
I’ve included a lot of information because I think it might be useful, but to save you from all the boring details I also added a summary of the symptoms and fix:
Symptoms:
Fix:
The full story:
I had the dreaded ABS and ASC lights appear but it wasn’t due to the common issues mentioned on here a lot i.e. solder joints in pump-mounted ABS module or any of the wheel sensors. Long story short I have a 1998 2.8 Z3 with the ABS/ASCT module mounted under the glovebox, which seems to be more common on the E36 than the Z.
I’ve included a lot of information because I think it might be useful, but to save you from all the boring details I also added a summary of the symptoms and fix:
Symptoms:
- ABS and ASC lights on after starting car. Lights off again after a few days then back on permanently after a few weeks.
- MOT centre identified the following fault codes using a “basic” diagnostic tool:
- Code 18: Operation of front left outlet valve faulty
- Code 17: Fault in power supply of all solenoid valves or operation of front left inlet valve faulty
- Took it to an indie but they could not communicate with the ABS/ASCT control module.
- Also tried a friends diagnostic tool and this couldn’t communicate with it either
- All wheel speed sensors working
- Relevant fuses and relays (K10 and K75) working
- ABS/ASCT module receiving 12v where it should be
Fix:
- Replace ABS/ASCT module 34521164094 with 2nd hand unit (off an E36 in this case)
- This turned off the ABS light but not the traction control light which is to be expected as it needs to be coded to the car
- Tried coding the module to my car with NCS Expert using the method that works for the other type of module found on the Z3, but encountered "Error in EDIABAS or in ECU description file (SGBD)" and other errors and could not write to the module.
- This was my first time using the software so it may have been possible and if anyone knows how to then please add to this
- More details below for those that are interested
- Visited an Indie (Autowerx in Milton Keynes) who used Autologic to re-program the module to my car, problem solved.
- The module cost £45 and they charged me £84 to re-code it. Better than spending ~£800 on a new one!
The full story:
- ABS and ASC lights on after starting car. Lights off again after a few days then back on permanently after a few weeks.
- MOT centre identified the following fault codes mentioned above using a “basic” diagnostic tool.
- They recommended an Indie (not the one that ended up fixing it) who could “probably get more detailed codes”. They couldn’t communicate with the ABS module so couldn’t retrieve any codes. They were however kind enough to still charge me £45 (I realised there were no codes after I paid… lesson learnt)
- That Indie estimated ~£200 to diagnose the issue but thought it was likely the K-Line. I was dubious so decided to diagnose it myself/take a punt on the pump.
- Based on some (quite poor) research I saw that the control module/ABS pump solder joints were a common issue. That, combined with the MOT station fault codes, led me to buy a 2nd hand pump. Replacing this didn’t fix the issue and the fault codes were still there. I also gained one relating to the front right wheel sensor somehow. This was a stupid mistake, at this stage I didn’t realise there are two versions of the ABS pump and control module for the Z3. I later found out that there is no control module on my pump (although there is a moduley looking black box on it) and that it actually sits under the glove box in my car.
- The seller of the pump assured me the part was working , I trusted him and started to check other common issues:
- All fuses were OK
- Relays K75 And K10: Applied 12v to pins 85 and 86, listen for the click, then check resistance between 30 and 87. These were both OK.
- Wheel speed sensors and supply to the module which required removal of the glovebox to check the pins on the module connector.
- I followed this guide to remove the glovebox: https://www.pelicanparts.com/BMW/te..._Replacement/73-BODY-Glovebox_Replacement.htm
- I used the wiring diagram found here: https://zroadster.org/threads/wiring-diagram.14747/
- Tested resistance across all wheel speed sensors, all similar, all OK.
- Tested the voltage of each wheel speed sensor by spinning each wheel. Each one was similar at ~1v AC when spun by hand. I wasn’t too concerned with the actual voltage, just wanted to see if one was significantly different to the others.
- Tested every source of 12v I could see in the diagram, everything looked to be in order.
- Faced with no apparent faults I started to suspect the module itself. I didn’t initially think a module sitting under the glovebox would be prone to failure but it turns out I was wrong.
- A quick google of the PN highlighted that this module is prone to failure and is relatively common on the E36.
- The module is “not repairable” according to the popular ECU specialist websites.
- I bought a 2nd hand module with the same PN (34521164094) that came off an E36
- Replacing the module turned the ABS light off but the traction control light was still on. This is to be expected as the traction control requires coding to the car, but I had at least confirmed that the module was the source of the error.
- I appreciate this next bit might not be that useful but I’ll include it so that someone can tell me where I went wrong if they know. I then bought NCS expert, INPA etc. off BC Cables to try to programme it.
- If anyone wants help installing this software there’s a great guide here: https://www.bimmerfest.com/forums/showthread.php?t=872584
- I tried following the re-programming procedure that works for the other style of control module (pump-mounted, under the bonnet version) but this did not work: https://zroadster.org/threads/abs-asc.12579/page-4
- I can’t confirm that this step doesn’t exist when re-coding the other type of module but just after selecting ASC as the module to process (ASCMK20 mentioned in the instructions wasn’t available) I was confronted with a window asking for SGET data (files and ECU name).View attachment 102783
- After hitting OK (and execute if I remember correctly) I received multiple errors along the lines of "Error in EDIABAS or in ECU description file (SGBD)":View attachment 102784
- I found the .prg file that it was referring to in the following location: C: > EDIABAS > ECU
- Tried changing the C_ASCT.PRG (SGBD) file to ASC_T.PRG in the same location (noticed the modified date on the latter was 1997 rather than 2003 so seemed reasonable to try that file considering my car is a 1998) but this didn’t work and I received very similar errors.
- Decided life is too short to spend all my evenings learning how to use the many pieces of software I had bought, and potentially risky to try things without understanding it all, so gave up and took it to another Indie (Autowerx in Milton Keynes). They re-programmed it to my car with Autologic, job done, time for a beer… and an MOT.
