318Ti - ABS Issue (Rough Running) - Fixed was ABS/ASC Cutting Engine Power

[The H. Behemoth 55]

So I think the issue I was having months ago with my little Ti finally came to light. I bought the car as a daily and after a few months the issues began after a speed bump and I have read how the ABS not working can cause the engine to misfire.

Anyway so today it was driving fine, no usual hesitation or misfires but I finally saw the ABS light came on (no issue with braking)

Here is what I get in INPA

ASCMK20

129 main relay inside control unit  - How do I get to the bottom of this? Is it a relay inside the ABS Unit or the relay in the fues box or is there one inside the ECU compartment?

121 height adaption (Error Load registration) - Unsure what this is for but I assume its related to the two.

175 Output suction pipe-switching   - This I understand is DISA Related? 

I cant seem to nail down if its the front two sensors or the ABS unit the culprit or some relay.
 

This was my first 318Ti and I really like the little guy, this is a issue I was not able to resolve however. Any input appreciated.

 

Edited October 8, 2019 by The H. Behemoth

[NZ00Z3 186]

The pump side of the ABS unit is usually very reliable, the electronics side is less reliable.

Have you used the activation part of INPA to exercise the ABS unit to see if there are any stuck pumps/valves.

 Attached is a file on the Z3 ABS electronic problems.  As you have the same unit it may be of interest.

BMW Z3 ABS Module Repair.pdf

[The H. Behemoth 55]

Yes I did AB activation part in INPA, but didn't do much. I wonder if its the speed sensor on the car? I see the grey one on the passenger side front, I wonder if thats the one the ASC is using.

I saw a few folks working on them on youtube, seems very straight forward. Now I wonder if the ABS could been related to the whole engine cutting power thing, maybe a good idea to inspect it and open it up tomorrow and see if the traction control and abs goes away and the error codes. May also delete the asct with a 10ohm resistor as found here - https://www.bimmerforums.com/forum/s...BS-light-fault!


I also wonder what the deal is with the 175 Output suction pipe-switching and how it can all relate to code 121 (height adaptation)...could never find anything on it, maybe its all ABS related.

I will try the repair this week and report back! Thank you for the input!

[The H. Behemoth 55]

Hi everyone, I have some fantastic news. All my issues have been fixed and the root was ASC & ABS. I did the ABS repair, and just went for a drive, no more misfires, no more hesitations! no more issues, didn't even need to disable the ASC. All is working great!

So I went after the ABS module today, took the electronic controller part off, cut the plastic housing open using a angle grinder (can use a dremel rotary tool) I found the dry solder joints. I re soldered it all then put the lid back on and plastic welded it (you can use the soldering iron plus some left over abs plastic to do such repairs) then cleaned it off with the grinder a bit and sealed it with some plastic epoxy just for good measure.

I also found a fuse (IIRC fuse 21 5A/32V I believe?) that was blown. Thanks to that fuse blowing I was able to narrow it more down to the ABS/ASC as I believe the solder joints after the speed bump were so lose that it was intermittent when the engine was pulling hard the ABS must had enough of a kickback/jerk to loosen the solder joints inside, then same applied going uphill and shorting that eventually lead blowing the fuse months later, which thankfully disabled the ASC and the car was able to just drive fine.

But now all is running fine, the ABS & ASC works fine and the lights have gone. The down side was when putting it all back together one of the ABS lines are now cross threaded which I will have to repair! Haha! I could had done the repair without taking the abs lines off (a little bending will be required). Something I will attempt to solve tomorrow or this week when time allows but for now I am so happy that my little Red Ti is working fine. Now I can leave this here in NZ as my holiday car!

Anybody having misfire issues, kindly check the code and for any codes, then  this code I had 121 Height Adaptation Load Management (which is not well documented online at all) this error code was all due to the ASC MK20 ABS module having bad solder joints inside that made things intermittent!

 

 

These are the pictures

 

 

 

 

 

 

 

Edited October 8, 2019 by The H. Behemoth