Figured I’d post this here as well.

Looking for some advice on my ‘09 R55. I finally got the engine installed and it started fine. After about 4-5 minutes of running, CEL came on, fail safe occurred, then the engine shut down. Scanned faults and only fault in DME was ambient temp. sensor (the bumper was off). There were other faults in the DSC, KOMBI, EPS, and IHKA for communication faults with DME. These faults would set after 2-3 restart attempts. Then I finally got fault 2BC4: Internal fault, driver CJ945.

Cleared faults, and 2BC4 would clear, but then return, sometimes immediately, sometimes after a start attempt. Along with that start attempt, I’d hear a rapid clicking clicking from the DME relay, which would stop when I turned the car off. I believe this relay is why the fault is being set and the car won’t start. The fault in the CAS module is a hard fault. Also got the steering lock symbol sporadically.

I swapped relays with another MINI I have, but with the same result. Could this be a faulty CAS module? I don’t have a factory wiring diagram in front of me ATM. I don’t believe it to be a bad DME.

Side note: my R55 does have comfort access, but i don’t have a key I can insert into the slot. Pictures are below. First 3 are the faults I currently have, fourth is the relay I swapped (actually swapped both DME relays), and fifth is the only key I have. The other faults in the DME I believe to be erroneous as they didn’t show up for awhile and the car ran well until this issue started.

 

To add some more context:
I bought the car back in October with a dead cylinder, but it was cheap and in great shape cosmetically. I rebuilt the engine with new injectors, new turbo cassette, and got it installed about a week ago. I started it once for a couple of minutes at that point and everything was good. I checked the wiring harness and grounds 3 times to make sure everything was connected and it was.

Fast forward to yesterday:

I started the car ran it for a minute, then shut it down to check a few other things on the car. I went back, started it up, and after about 4-5 minutes or running, mainly idling as it's still on the lift, it went into fail safe mode, then about 20 seconds later, it shut down. I attempted to restart it, and it started for a couple of seconds, then shut down again. tried to restart, and it just spun with meager attempts to start. The DME relay (pointing to it in the picture) clicks A LOT when the engine stops cranking. I swapped that relay and the one above it with ones from another Mini with the same issue.

I figured maybe the fuel pump died, so I checked fuel pressure at the HPFP while cranking and pressures got up to around 1400 psi, so the fuel pressure and pump appear to be good.

The fault listed are after many attempts to start the vehicle and cleared multiple times. The one that is a hard fault is the one in the CAS. The only fault that is consistent in the DME is the internal fault, but even then, it set a lot of the time. The communication fault occur, but only after cranking for a wile and multiple start attempts, so not right away.

I'm trying to figure out if this is a CAS or DME related issue. The DME I can always send off to have tested, but it'll cost me around $150-200 to have this done and I don't want to do it unnecessarily. I don't want to pull the dash half apart to remove the CAS module unless I can determine this is the most likely source of the issue, and if it i, I'll just buy a new one from MINI as it's less than testing and repairing.

I have also disconnected the battery multiple times when working on the car to make sure everything was okay, including the pins at the DME and everything appears to be in good condition. Communication with the DME and my scan tool has never been an issue and with the DME relay acting the way it is, I can see why communication faults would occur.

Any help would be great and if more information is needed, please let me know.

 

What is the health of the battery? Almost sounds like the battery might be on its way out.

Unfortunately, the only service plan for a recurring 2BC4 fault is to replace the DME.

https://bmwfault.codes/

 

That’s what I’m thinking, just didn’t know if the clicking relay could have set the fault (low hopes). Just never had a DME fail on me while running. Could it possibly be a faulty JBE? Is that what controls the DME relay in the engine bay?

 

Just wanted to update that it was in fact my DME, due to the ground wire on the valve cover breaking while it was running. Had to get a replacement DME from ECU Pros. Car now runs.

CEL is on, but haven’t had a chance to check/clear faults and CEL does not set new faults, so hopefully stored faults. We’ll see!