[Raleigh3rd]

I'm just finishing up my 04 coupe project and I'm having a transmission/TCM issue hopefully someone can help me out with.

The car is an 04 sulev M56 car. I bought it with a bad engine (no compression on #5). It ran rough but was able to drive on the trailer and around the driveway. No transmission issues.

I pulled the M56, and replaced it with a M54b30 from the junkyard. I replaced the fuel tank, fuel lines, filter/regulator and evap system with parts from a standard (non-sulev) car. I'm still using the original trans.

When separating the engine and trans, the torque converter fell off. Between that and the trans cooler and lines, I lost a fair bit of transmission fluid.

Everything went together pretty easy, and I flashed the DME with the latest software for M54b30 automatic using WinKFP.

I filled the trans, ran it thru the gears, and rechecked the fluid.

First drives were great! First one was on the original m56 tune, the second was with the new b30 tune. It ran strong, went into sport and manual modes no problem. I'm pretty sure I was able to check for errors in INPA, but not 100% I got that far.

Then I disconnected the battery to do a couple odd electrical jobs. One was to wire in a fuel pump relay to replace the control module from the M56. I added a wire to a DME plug (#4 pin 10 if I remember right) to trigger a relay in the trunk. I'm using the original power and ground wires that went to the EKM. I also played around under the glove box, fixing some bad wiring for some faulty old angel eyes.

After hooking the battery back up, the dash shows the orange cog with exclamation mark. The trans is in full limp mode. I tried to read fault codes for the transmission in INPA, but I get a job status error that says "(error_ecu_nack) instead of (okay)". If I try to use WinKFP to update, I get several 2020 codes saying "ECU does not answer".

I've checked the two plugs at the trans, and the connections in the DME box. I've also rechecked the fluid level and ground points (2 fender, 1 firewall, 1 engine).

I'm at a lost and looking for any input. I'm starting to think the TCM is bad, but seems like too big of a coincidence considering it was fine before.

Thanks in advance.

 

[Bali]

I would go back over each of your wiring changes while comparing them to the diagrams on newtis.info. See if there is some wiring change that affected the EGS.

Read trouble codes from other CAN bus modules (DME, ABS, IKE) to see if they have codes related to communication with the EGS.

What’s the battery voltage?

 

[Raleigh3rd]

Sorry for the use of wrong acronyms, I'm still adjusting to all of the German. If the trans module is EGM, what is the TCM that I see in NCS Expert?

Thanks for the link to the wiring diagrams. I've been looking for a good source. I will study them tonight and see if there is any wiring conflicts.

DME returns no errors. I read the codes for DSC in INPA, came back with "5E15 CAN Timeout EGS". Would I check ABS in a different menu? I didn't see an option for it in INPA. I will read IKE tomorrow.

Voltage sits at 12v+ when off, 13.7v when running.

 

[Raleigh3rd]

SOLVED!

I ended up swapping the EGM (TCM) for another unit today. Both had GS 8.60.4 and the same part # printed on them. It completely fixed my issues.

The car shifts great, no cog symbol and goes into sport and manual modes.

I can't recall a moment where I could have harmed the module, but I'm sure there was something I did to bugger it. I wish I knew what happened.

Well, that seems to be the end of this stage of the project. The car drives and feels like a factory 330ci, and nothing but the good parts are left from the M56, all for under $2k. I did two decent test drives today, and no CEL or issues of any kind.

Next up is 330 brakes, a six speed swap... Thank you BaliDawg for your input.