Car going CRAZY when turned off - PLEASE HELP

[FSU BMW]

Hi all,

I own a 2019 740XE (e-drive), VIN: wba7j2c53kb246415 with ~1,700 miles.

It was a previously flooded title - the BDC, GSW, fuel pump module (TFE), ACSM, were all replaced by the dealership when the car was purchased at auction (along with carpets, other things).

Car runs / drives like new (basically is, very low miles) - absolutely zero issues.

However, when I shut the car off, the car goes absolutely insane - the windshield wipers come on, the brake lights turn (and stay) on, and a bunch of phantom faults start appearing in the instrument cluster (drivetrain malfunction, headlight malfunction, etc).

Even after I lock the car, the car keeps going nuts - windshield wipers / brakes keep going, and the only way to stop it is to physically turn off the battery.

Once I start the car, there are zero faults, and the car is working perfectly. Also when I put it into diagnostic mode (to connect to ISTA), it is fine, and not going crazy.

It's a very weird, but annoying issue - when I run ISTA, I only get one existing fault: AC-LIN temporary failure of the electric auxiliary heater. However, I don't think this is relevent to the car going nuts - also the A/C and heat work perfectly fine.

I clear those nonexistant faults, but as soon as it deletes the faults, the car starts going crazy, and then shows the same nonexistant faults.

Both the battery, and auxiliary battery are brand new, already changed those out.

ANY ideas? I really appreciate the help, because I cannot afford to go back to the dealership. ISTA is clearly reading all the modules, so I don't want to go back and replace any modules just yet (several were already changed).

Should I check fuses? Reprogram whole car? (When BMW changed out the BDC + other modules, they programmed only those modules - could software difference cause this problem?) shawnsheridan this is an area I could really use your help

[Raimo5]

Well, BDC sending out invalid data is suspicious, but it can if it itself has bad data. You might need to delve in to that KL15 short to ground issue first as this might be the root cause.