I have a 2015 Cooper S F55 that has been running great until yesterday. I was driving the car and stopped at a light and the auto start/stop switched off the engine. When the light turned the car would not restart. The dashboard will only flash briefly and then shut off. I still have power to the interior lights/chimes and windows. I replaced the battery with no change. I pulled and tested all the relays/fuses and they all seem fine. Any ideas what might be causing this?

 

When you replaced the car battery did you code it? It needs to be coded to tell the car the battery is replaced.

Also with an OBD2 reader you can pull codes.

 

The ignition will not say on to be able to connect to an OBD reader or to ISTA to code the battery. When I hit the start switch the dash flashes and the fuel level lights go up and down and then everything turns off again. This is with or without the clutch engaged. I tested the old and new batteries and they were both functioning normally. All the door locks and interior lights work. I can here the fuel pump prime when I get close with the key fob. The fuse panel is getting the correct voltage. I’m starting to think the start/stop switch console is shorting or something.

 

I would start with the start/stop switch console too. If that's not it, then move onto the starter. Good luck!

 

Sorry for responding on an old thread but i'm having the exact same issue on my '17 F55. Did you ever figure this out?

 

Check your grounding strap. It gets corroded and doesn’t carry the ground current. Replaced it with some heavy gauge wire and it started right up. Had this happen on both my ‘15 minis.

 

Thanks! Its currently at the dealer (not MINI, just the dealer i bought it from) since i have a 3000 mile drivetrain warranty with them. I called and asked them to check this and they claim they already did. I'll go out there and drive the point home or, just collect the car and fix it. Much appreciated!

 

Bingo. Car is fixed and it was a chassis ground strap. They aren't even charging a diagnostic fee since I told them the diagnosis. Thanks again!