M52TU MDK. Yikes, P1542. Anyone have notes on connector pin resistance values?

[bjornk]

If you find out please share. My new mdk had a note it it that said to be sure I’ve upgraded dme to latest version so I’m doing that first and dealing with it until then after that I m going with the loom,

I called a stealership and asked them if they could ballpark a fee for loom diagnostic and they said no, bring it in , they have never see one where the loom was the issue...so I’m looking for an Indy.

I know I can do the loom, but if I’m wrong and wasted 700 I’ll be pissed.

At this point I’m thinking I already wasted 5 on an mdk



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[osc911]

I had a spare engine (don't ask!) so swapped the MDK from the spare engine (I have the loom for it as well).

The connectors are available from BMW using part number 61131393724. I ordered 12, they are only 27p each.

Here is a guy that went on the same path before us.

https://forum.e46fanatics.com/showpo...0&postcount=12

I swapped the MDK but the error came back. I haven't touched the round MDK connector, but when the error comes, I wiggle the rectangle 56-way ECU connector and it is fine again for a few starts. I have taken out each MDK pin and tried to squeeze for better contact but it's very tricky and I don't want to overdo it and damage the ECU side.

*update* I am in the process of swapping the loom over and the old one is out. I'm doing this to eliminate both wiring and connector issues, plus I already had the loom, and I have the occasional transfail error which may also be due to a weak connection.

[osc911]

So I went for it and changed the wiring loom. It was a bit more involved than I thought, partly because my car also has an LPG system.

The new loom is in, yesterday car was working on petrol, and today I reconnected the LPG system. So far it has been totally free of any engine fail safe and trans fail safe faults. I've had 8 journeys, and 2 driving it very hard.

[bjornk]

Mine is on the way. There were only 3 in the us. Was told I may even have to wait on one from Germany . Did your new loom have gold plated connectors or did you go used? I was told by a tech that was on old bmw cert mechanic that while there was no recall, it was a common service practice to switch the Harness to an updated gold connectors if under warranty... if this is true , I bet cars that got serviced by Indy’s did not get this done as freely..


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[osc911]

I had a second hand loom, a week on all is still good with no errors at all.

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[nareck]

Hey people, I am also having these MDK problems, they are now a big part of my nightmares... I'm on my third failed used MDK.
Getting the following error codes in INPA (randomly):
119 (77) - MDK throttle mechanical sticking
173 (AD) - Signal, throttle position sensor, potentiometers 1 and 2 short circuit
169 (A9) - Motor-drive throttle valve output stage cutoff after diagnosis fault


My car is E30 with M52B28TU swap. Being an "all-manual" car (without any traction/cruise controls etc) I am wondering if it's possible to hack the ECU so that it ignores all the "electronic" stuff of the MDK?

Thank you to everyone who have contributed to this thread (though it didn't help me so far).

[effduration]

Hey people, I am also having these MDK problems, they are now a big part of my nightmares... I'm on my third failed used MDK.
Getting the following error codes in INPA (randomly):
119 (77) - MDK throttle mechanical sticking
173 (AD) - Signal, throttle position sensor, potentiometers 1 and 2 short circuit
169 (A9) - Motor-drive throttle valve output stage cutoff after diagnosis fault


My car is E30 with M52B28TU swap. Being an "all-manual" car (without any traction/cruise controls etc) I am wondering if it's possible to hack the ECU so that it ignores all the "electronic" stuff of the MDK?

Thank you to everyone who have contributed to this thread (though it didn't help me so far).

I doubt it is possible to hack the ECU this way. I have been thru this with several failed MDKs
my suggestion is to get a used M52TU engine harness from a known running parts car and swap it in. A new harness is better, but they are quite expensive..like $600

[osc911]

+1 this worked for me, I think it's the best way is the car is a keeper

I doubt it is possible to hack the ECU this way. I have been thru this with several failed MDKs
my suggestion is to get a used M52TU engine harness from a known running parts car and swap it in. A new harness is better, but they are quite expensive..like $600

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[nareck]

I doubt it is possible to hack the ECU this way. I have been thru this with several failed MDKs
my suggestion is to get a used M52TU engine harness from a known running parts car and swap it in. A new harness is better, but they are quite expensive..like $600

Here's my car's, which was my daily driver, MDK fail history:
1. happened with previous owner (who did the swap), not sure about timeframe, probably min 6 months after the swap. He had another failed one, he did some DIY-merge those two together.
2. happened to me after 6 months in city traffic, reset the codes, drove couple of days, bought a used one, changed it
3. A year later failed on me when I arrived at the cemetery, of all the places... After that I took it to mechanics, they checked the wiring from ECU to MDK meticulously, they have even pulled out the ECU module and checked the board - no problems. When they put everything together, reset the codes, started the engine, almost instantly failed again. So they gave up.
4. So the poor thing stayed in the garage for a year and a half now, recently I finally had the energy to give it another try, bought another used MDK (blue label first time). Didn't notice that the flap was stuck in closed position, was able to open it only by hand. I knew it's a bad sign, but still installed it. After idling and depressing accelerator couple of times it was OK for about 20 mins, then I slightly touched the accelerator pedal it stalled and when I started up it was in limp mode again.


It seems that I'm just having some bad luck with MDKs. But I know that the only true solution to this problem is to buy new MDK then new harness. But if my harness passes the wiring test what's the logic behind buying another one?


BTW, yesterday I came across this video which helped me to avoid buying another used MDK: https://www.youtube.com/watch?v=WkdnhUxx8OY
Like with the previous one, the one I've avoided to buy almost didn't have the lower limit play shown at the first part of this video.


Sorry for the rant, had to get it out.

[bjornk]

Just closing this out: seems wiring harness was issue. Been driving couple months now ... no issues with mdk.


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