Author Topic: E36 Compact M43 To M42 Swap - ECU ERRORS  (Read 5697 times)

PelsonBMW

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E36 Compact M43 To M42 Swap - ECU ERRORS
« on: July 14, 2017, 04:10:49 AM »
Hello ! I recently bought for my fiance a Compact from the end of 1999 with the m42b18 (140HP) motor, formerly was m43b19. After the purchase i had a little trouble with it and with the snakes and vacuum, etc. (with underpressure I'm not sure that everything is connected properly), I replaced the temperature sensor in the block, I installed a new lambda sensor, crankcase vent, replaced spark plugs, idle engine speed control motor and The vent of the tank (no carbon filter) sucked on the filler cap and now it squeaks through the small valve (it releases the pressure and I do not know if it is related to the uneven engine running at 850rpm). The engine sometimes waves but it's probably the nature of the m42b18 although I saw the units working normally. I have a problem and it is quite strange because the lambda probe is new, I noticed that the computer jumps with error 201 - lambda sensor adjustment - when the error is cleared, the electric fan shuts off for a moment and once the fan turns on it crashes error 201 from the probe. When the fan does not work then the probe error is not there ... just turn on the fan and again the probe error. The fan can immediately switch on the first gear after turning the ignition switch (only when i was driving a car before) on ​​the cold also sometimes turns on the fan, such as the car is standing all night. What is it about this probe? I exchanged 3 probes and on every probe i get same error. I also add that when I push off the temperature sensor the first one in the block, the RPM will rise for a moment and then again are normal but it crashes the sensor temp and rotation  I will throw screenshots of inpa and values.
Okay, let's add that I recently wanted to unscrew the temperature sensor and I cut off the tip of it, I put some black with the same thread, maybe it's a temperature sensor scratched? Because first on the block from the front is blue, I've put black from R6 m52 instead blue from R4, the second one is black and he gives the temp on the clocks. Clocks in the car changed to those from m42, because after putting the old ones (original from 1999 from the m44 ), The temperature indicator on speedo goes to red square immediately .

Sorry for my english but i'm from Poland and im not using English all day to wrote perfectly :P but i assume that many of you could understand me :)
« Last Edit: July 16, 2017, 06:46:39 AM by PelsonBMW »

1998ccc

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Re: E36 Compact M44 To M42 Swap - ECU ERRORS
« Reply #1 on: July 14, 2017, 10:48:13 AM »
I assume you are still running the m44 OBD2 harness.  THe M44 used a single temp sender for the DME and gauge.  Did they move that sender over when they did the swap?  M42 will have a blue sender in the  front for the DME and another a few inches behind for the gauge both in the bottom of the head oil filter side.

Electrical diagrams here if you don't know.

http://wedophones.com/Manuals/BMW/
« Last Edit: July 14, 2017, 10:50:59 AM by 1998ccc »

PelsonBMW

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Re: E36 Compact M44 To M42 Swap - ECU ERRORS
« Reply #2 on: July 14, 2017, 02:08:51 PM »
i have engine harness from m42... i have two temperature sensors , one in front is blue and the second one is black , when i unplug the black one i dont have a temperature on speedometer , when i unplug the blue one , rpm rises up to 1.5k and goes down . Oh and the wires are directly connected to speedo and dme
« Last Edit: July 14, 2017, 02:10:59 PM by PelsonBMW »

1998ccc

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Re: E36 Compact M44 To M42 Swap - ECU ERRORS
« Reply #3 on: July 14, 2017, 10:31:22 PM »
Is it possible to get the original harness for the car.  You can run a M42 on a M44 harness without all the headaches of backdating to OBD1 and avoiding EWS issues.

PelsonBMW

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Re: E36 Compact M44 To M42 Swap - ECU ERRORS
« Reply #4 on: July 15, 2017, 01:32:00 AM »
I don't have any ews issues,  I'm thinking why it keeps throwing a 201 lambda probe error - regulation...  Maybe it's a oxygen sensor fault?

1998ccc

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Re: E36 Compact M44 To M42 Swap - ECU ERRORS
« Reply #5 on: July 15, 2017, 11:25:58 AM »
http://www.exx.se/techinfo/docs/si_12_09_95_022.pdf

Says 201 is sensor 2 which is the downstream O2.  If you switched to OBD1 with the early DME it only has the one O2.  Sounds like you are still running the OBD2 computer which needs a signal from both O2's.

PelsonBMW

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Re: E36 Compact M44 To M42 Swap - ECU ERRORS
« Reply #6 on: July 16, 2017, 06:45:29 AM »
My fault,  old engine was m43b19 105HP  not m44 :D but i have a m42 computer(dme) connected to the harness , even on DIS , INPA and Delphi diag doesnt show the second lambda
« Last Edit: July 17, 2017, 04:07:11 PM by PelsonBMW »