I'm hoping the forum might have some ideas as I'm out of them at the moment. Let me take a moment to explain what has happened, what has been done and where I'm at right now. I'm new to posting so please bear with me

My son bought a 2012 Countryman S All4 1.4L Turbo and after a few months noticed a noise coming from the engine. Just a rattling that would come and go. took off the valve cover to look at the what might be causing it and noticed the timing chain guide had broken at the mount point and was just in there loose rattling on the chain. Ok, no problem. Ordered a new chain guide and he and his friend replaced it and the gasket and put the value cover back on. Here's where the issue starts.

They forgot to connect the ground wire that attaches to the block between the air filter and engine. When my son was cranking the car it wouldn't start and just kept turning over. While he was trying to start it, his friend noticed the ground wire wasn't attached and went to attach it. He got a good shock as my son was cranking the engine at that time. They went to attach the wire and the ring connector snapped off.

I attached a new ring connector and the connector showed continuity and grounded. After reattching the ground cable, the car turned over then fired up after a few seconds. That's when everything went south. Every sensor came on. Anti-lock braking, oil pressure, tire pressure, stability control, crankshaft, camshaft. I mean every sensor reported an error and the car went into limp mode and could tell it was running rough.

Thinking they might have friend the DME, I pulled it and sent it along with the CAS unit to the ECU pros out of Pennsylvania. That's all they do is ECUs. They found no issue with the DME and it was working fine and talking to the CAS. They flashed the firmware/code and then sent it back. I plugged then back in and am back to square one with the car reporting all the sensors.

I'm stuck and not sure what to look for next honestly. I live 2 hours away from the nearest MINI dealer and would have to tow it on the flatbed to get it there. Before I go that route I am hoping someone might have ideas as I have read a few threads about the ground wire to the engine being a source of many issues, even when just changing the air filer.

 

Perhaps since the ground was found disconnected that maybe there is another connection somewhere being overlooked. Do you have a code reader for the Mini?

 

I do have just a ODBII code reader and that what throws all the faults. When removing the valve cover, you have to remove the grounding wire that is on the back side that sits between the cover and air filter. It is part of the wiring assembly for the DME and that wasn't put back into place during reassembly of the valve cover. There weren't any other wires that needed to be removed.

 

You said you had to repair the ground. Perhaps the other wires are damaged and/or connector issues. Wiring and connection issues can cause the pages of codes since the computer was tested and good...

 

Thanks for the feedback. One thing I also tested was ALL of the fuses and relays and all are working as they should. No blown fuses or relays. The fact that the DME tested out as working but in the car it is throwing all the codes made me think about tracing exactly where that ground wire goes. Here's what I found so far.

The initial single ground wire to the engine block behind the valve cover routes back to the fork that splits from the DME to the two harnesses that go the coil pack. The one wire is housed in a 4 way splice that has two going to each side. From there going backward to the DME, the spliced wires are merged into one green wire that connects back to the DME in the middle connector. In between the 5 wire splice down to the single wire is what looks like a connector which is heat wrapped and I am thinking of exposing that to inspect the connection. I don't see any burning or visible signs of damage anywhere. I was thinking I could also test continuity at this point to make sure the ground wire on the valve cover is actually creating a ground back to the DME.

Because the original issue was with the ground wire itself, I'm still going down that rabbit hole. Thanks all for responding!

 

Welcome. These electrical issues can be a real pain. I felt like lighting mine on fire when I first got it (used) because of an intermittent electric issue. Mini couldn't figure it out even and I had a page of codes. I ultimately found it is was an intermittent (bad) relay to the DME that was the problem. I swapped the relays (DME and Cooling which were the same) and the car has been fine since and problem solved. I have a spare fuse box and wiring I sourced from Ebay in an attempt to find a connection issue, but turned out to be relay hardware.

You're on the right path to troubleshoot and verify ground and power there.

 

The ECU Pro in Wellsboro PA is where I'd sent my footwell module (FRM). I'd read they were reputable and was happy with what I received.

I've always thought that tiny wire mounted where it is was suspect from an electrical engineering standpoint. Something you look at and wonder "why...?" That he managed to get a shock from it indicates a significant sudden surge in current along that wire. Wherever it's carrying current from is suspect as fried. Note, I'm no expert and my words are worth what you've paid for them. Muddling your way through the circuits is probably what you're stuck with. BMW TIS system might give you electrical diagrams, for a price of course.

It wouldn't hurt to post the codes you are receiving from the OBD scanner. A proper scanner that can show the bmw-specific codes may help. Such scanners usually offer live data as well, might give you insights.

 

Adding an update. First off I was really impressed with the ECU Pro folks. As I thought the DME might be blown, they tested in along with the CAS module (that think is VERY tough to remove... ask me if you need to remove the CAS sometime. It's under the driver side dash). As they found no fault they only charged me for testing and refunded my replacement price. Very stand up of them!

I thought I would start working my way down the line on the ground wire. I have been still hung up on that as it made no sense that you would have a little wire that controls the DME and coil packs with NO protection in place. So i went ahead and disconnected the battery and then pulled out the wiring harness that has the fork for the coil packs and ground wire and pulled back through so it was loose straight from the DME and not routed underneath. I wanted to trace the ground wire as I couldn't find a wiring diagram. What I found is the ground wire (working backward from the ground bolt on the block/valve cover to the DME) routes to a 4-way connection that is epoxy'd and weather wrapped. From there two wires go to each coil pack and one wire back toward the DME. The single black wire back to the DME has an inline capacitor (100nF 100V) that you can only see if you pull back the wiring harness. Ok, so perhaps they did put a safety mechanism before blowing your DME I thought. I then hooked everything back up, the coil packs/wiring, ground to the engine/valve cover, connections for the DME and then tested continuity back from the DME connector (mapped it to pin 5 on the middle connector). Here's what I found:

- No continuity at the pin connector that connects the ground of the coils back to the DME (and ultimately grounds the DME)
- No continuity upstream (DME side) of the inline capacitor
- Continuity to everything downstream of the inline capacitor

To just make myself feel better I also connected the battery and had power but not running in the car. Same results. Grounds all good to coils but after the capacitor it's no good.

So I'm thinking this capacitor blew when my son's friend decide to make himself the ground. I'm including a picture of the piece I'm talking about. As this is all part of a wiring harness, I'm betting there's no way to find the capacitor.

I did take pictures and video and including the picture of the capacitor here.

capacitor from the coil packs back to the DME. DME would be to the left (green wire)

 

Looks like you found the interference suppression capacitor for ignition coils? In my opinion, you really need a copy of ISTA+ if you are trying to trace wiring. Or just pay the $32 for 24 hours of access to https://minitechinfo.bmwgroup.com

 

I would assume the capacitor is within that black heatshrink cover. I haven't had enough time to look into this, but a guess would be soldering in a new capacitor where that one is in the image? It's giving you voltage and capacitance rating, don't know the power rating in Watts sadly.

EDIT: Disregard me, BlazingE60 clearly put more effort in. *thumbsup*

 

Thanks for the data. I'm kind of a data driven person so it's appreciated.

I tried to find the manual and electrical schematics but it's all hidden behind buy this. I don't do cause I don't know if they are selling what is needed.

Thanks for that layout and that there's a subscription model. I didn't know that.

Here's the current situation. I found a salvage person in Jersey that had an OEM engine harness. Thinking I'll just splice in the capacitor which I'm just assuming should be good. I know not guaranteed. I'll keep everyone posted next week as they just shipped the harness