Usually I encounter some more difficult problems, and I will record the process of solving these problems. This time the problem is the same, the failure occurred on my commute.
Have BMW E32 (hit 250k) with a issue: Been having an cold start drivability issue where it feels like my transmission is cycling of and on during acceleration. I will have the issue in any gear under load. The issue disappears about half way through my 20 minute commute to work and by the time I get off the freeway the issue has disappeared. Hooked up my foxwell NT530 tool and was able to pull code 54 from the DME for “Converter Lockup Clutch”.
What I tried:
Fluid level was good.
Tested MV3 TC lockup solenoid and the resistance is very high! 485ohms to be exact.
Before I continue I want to make sure im testing the correct pins because when went to check the resistance of MV2/3 there was no pin in the connector.
Is the view numbered looking at the connector or from behind the connector?
I forgot to mention that I do not think I have the correct wiring diagram information to test at the TCM.
Using the electrical troubleshooting manual numbering I had that extremely high resistance reading for MV3, but when I went to test the MV1/2 there were no pins available at X2000 to perform the test. The same is true even when viewing the connector mirrored.
However, it will set the code if a problem is found in the circuit and since none of the other solenoids are triggering a code ground side testing will be the next step if this fluid swap doesn’t remedy the issue.
I just took the vehicle to autozone for the dex and had no issues
Finally! The problem is sorted out:
Changed the fluid last night and had no issues during test drive but the problem occurs mostly when the vehicle is cold so this morning I took the vehicle out for a drive and the issue was right back.
Last night while looking through zf service info I found that the TC solenoid is not a factor during the parameters in which the issue is occuring. This was confirmed when the same “tick” began occuring with the vehicle stationary and in P.
With the solenoid eliminated from the equation I decided to pop the hood and take a look around. After staring blankly into the engine bay for a solid 10 minutes I noticed that my newly replaced crank shaft position sensor was slowly having its wiring eaten into by the water pump pulley….
In hindsight, I should’ve cleared that code 54 (which was probably from last year) to see if it would occur again. When it didn’t, I would’ve known to begin look for the issue elsewhere.
Tldr; My crankshaft position sensor wiring was damaged and causing the issue.
Credits to @ chazsandiego
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