Hey guys, I am really in a pickle here and could use some fresh-minded opinions.

Put the car up on jack stands to do all 3 engine/tranny mounts today with Powerflex inserts.

Upper motor mount was far far easier than some made it out to be, marked the headlamp position etc for reinstall, all good.

Knocked out the rear lower mount in a matter of minutes - 3 bolts off and on. Sweet.

Then went to address the gearbox mount on the drivers side...

After removing the airbox, I understood the battery tray was in the way. Proceeded to remove the battery, ECU, all plastic and barriers to get the battery tray out, only to realize there was about 1-2mm between the mount staying in the chassis rail and coming out. I did realize the tranny mount is needing replacement (don’t have the part on hand), so decided to admit defeat and chose to address once I go to install the front sway bar since I need to drop the subframe for both. Realizing I was in a race against the sun going down, re-assembled the car.

Upon first startup attempt, car was turning over but no fire up and start! At first, it showed me a “Drivetrain malfunction: Drive moderately. Maximum drivetrain output not available. Consult service center.” I took a peek in BimmerLink and found 14 error codes in engine electronics! (Mind you all I recall touching were a few sensors that needed to be temporarily unplugged + the ECU). They are as follows:

109001 Coolant temperature sensor, electrical: short circuit to positive
1BC115 Gear sensor, electrical: short circuit to positive
1C3002 Engine oil pressure sensor, electrical: short circuit to ground
108A06 Charge air temperature sensor, electrical: short circuit to positive
20A504 Turbocharger coolant pump, control: open circuit
107A50 Throttle valve: emergency operation active
100A04 Throttle valve, throttle valve potentiometers 1 and 2: double fault
101001 Throttle valve, throttle valve potentiometer 1, electrical: short circuit to positive
101202 Throttle valve, throttle valve potentiometer 2, electrical: short circuit to ground
191004 Tank ventilation valve: control: line interruption
160001 Crankshaft sensor, signal: missing
121001 Boost pressure sensor, electrical: short circuit to positive
104401 Absolute pressure sensor, intake manifold, electrical: short circuit to positive
1D2404 Map thermostat, control: line break

The car was stationary and never turned on the moment it went up on the jack stands, just battery disconnected and pulled along with ECU.

Did I swap some ECU wires? Leave something unplugged? ANY thoughts are welcome, I am stranded and this is my daily, gf is at a wedding out of town so stuck ATM. I recognize it might be something simple but before I start tearing things back down, wanted some fresh input as I am a bit tired from doing this all day. Help me fellow MINI friends please 🙏🏼

 

UPDATE:

Knowing it was dark and getting late, I decided to leave the car overnight fully assembled and attack fresh in the morning.

Pulled the airbox and battery connections to inspect the ECU plugs and their seating. Seems the middle of the 3 rectangular ECU plugs was not seated fully/correctly (clip was closed but not fully on). Reseated every plug, reassembled.

Now all 14 engine electronics codes disappeared BUT now after reassembling, I get a hard brake pedal, can hear the fuel pump running but not even trying to turn over like before. Instead, I get the following errors in the Infotainment GUI:

- Chassis stabilization: drive moderately (would love to but car doesn’t even start or try now)
- Auto PDC Malfunction. Activate PDC manually.

BimmerLink shows:

Permanent errors:

FFD356 (no description) Dynamic stability control MK60 E5

+ 20 new error in Error memory for Dynamic stability control MK60 E5

QUESTION: what is the little black box sitting next to the ECU with wires attached to it?

I feel like I am starting to chase ghosts and this car was flawless prior to battery tray disassembly. Can anyone provide any insight, things to check I haven’t covered, connect me to someone who possibly could have input, ANYTHING. Given that the engine codes all went away after reseating the middle long ECU plug tells me this is a simple wiring issue. Thing that gets me is now the car does not even want to try to start? What am I missing or overlooking here?

 

UPDATE 2:

For the third time, I meticulously disassembled the battery box area, again pulling the battery, and disconnecting every wire. I very carefully made sure all connections were secure and routing of wires was exactly as the factory had set them. Fully reassembled everything to the last bolt and noticed this time when I connected the negative terminal of the battery, there was no immediate warning ding from inside the car. Buttoned it all up, go in and hit the start button… it STARTED! A bit vibrational due to the new Powerflex mount inserts in the upper and lower motor mounts, but running. HOWEVER, car is in limp mode.

No power, but all things seem to be working. I have the following in the Infotainment GUI:

- Chassis stabilization; drive moderately
- Drivetrain: Cont. driving possible

I literally in all 3 disassemble/reassembles simply did the same exact things: unscrewed panels/parts and unplugged/plugged in connectors. NOTHING ELSE.

BimmerLink shows a whole host of codes again in Error Memory.

Open to everyone’s input and ideas at this point.

 

Man, I hope you get that sorted out! Might not be any help, but have you tried clearing the codes?

 

Document all info, error, and permanent codes (if any -- sounds like you just have info and error); then clear all codes; then see what codes come back, and post them all (by category, meaning info vs error vs permanent) here.

 

This is going to sound really dumb….

Cleared all codes (already all documented) and car is running like a champ once more. Thinking the one ECU plug not fully seated set them all off, then the codes persisted even though I had resolved it on second reassemble. Just took the car out for a gentle ride, then in Sport, then a few WOT pulls on the highway. All good 👍