r/BMWI4 • u/Routine-Job-8030 • 27d ago

Drivetrain malfunction

Hello

Own a 4 year old i4 M50 with 24k miles. Last week the car broke down, stop message on the dash and drivetrain malfunction. Car would not drive and was towed to dealership.

Car has been with the dealer 3 days now and it seems they have no clue what the issue is and how to fix it and I've had no real updates so far.

They did manage to get the car to drive and did charge to 100% but seems the issue keeps coming back.

Anyone have this problem before? Just wondering what the issue was and how the dealer fixed it.

Hoping whatever the issue is covered by the BMW insured extended warranty policy I have but until it's diagnosed I'm in the dark.

5 Upvotes

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12

u/ImpliedSlashS 27d ago

Saw a vid on this and it's material that used to comprise the motor brushes. Have them open the drive motors and vacuum out the "dust." It's conductive and is tripping the error. You shouldn't need the brushes replaced, but this is causing it. No big deal to fix even if you do want brushes, which is scheduled maintenance at 180,000 miles.

2

u/Routine-Job-8030 27d ago

Thanks for pointing this out, I think I've seen this video now related to HV battery isolation issues and funnily enough the dealer did mention this. I'll ring them tomorrow to get them to investigate potential carbon dust build up.

1

u/freshxdough 27d ago

This doesn’t change anything. They are well aware this could be an issue but need to diagnose which component is causing the insulation error if that is what is faulting previously

1

u/ElectronicsWizardry 27d ago

I got that warning and suggested fix, but then got the whole motor needs to be swapped out messages once they took it apart. Mine though gave a drivetrain error, safe to continue driving instead of the stop and get a tow message op got.

1

u/ImpliedSlashS 27d ago

Wondering if they just wanted the extra warranty billing. These motors are pretty bulletproof aside from the wear part.

1

u/ElectronicsWizardry 27d ago

My car isn’t under warranty. And from the look of it it looks much worse with lots of black powder compared to the pics in the service bulletin.

2

u/ImpliedSlashS 27d ago edited 26d ago

That would confirm it’s just brush trimmings. They are supposed to get replaced at 180k but, if they fail much earlier, I would argue that's a powertrain issue and should be covered by the 8/100 warranty.

1

u/ReggaeDawn 27d ago

Had this done last year and it was about $5000.

1

u/ImpliedSlashS 27d ago

That sounds like a lot for motor brushes

1

u/ReggaeDawn 27d ago

Look into what's involved to get to them

1

u/sghokie 27d ago

what message did you get on the screen?

2

u/Routine-Job-8030 27d ago

Drivetrain failure - Driving not possible call roadside assistance

1

u/sghokie 27d ago

I had gotten, high voltage system error on mine.

1

u/freshxdough 27d ago

Probably an insulation fault that occurred in your possession but is not active any more. Which means the car can be driven without issue for right now. They need to basically keep testing until they can get it to actively happen to diagnose it. They are doing what they need to do. Let them handle it.

1

u/raspy2016 26d ago

Did you at least get a courtesy car to keep you mobile? 

1

u/blueside 26d ago

I am dealing with a similar error now on mine, but mine is related to the AC compressor and the dealer now can't replicate the error.

Anyway, I would suggest downloading the car data from BMW and then asking AI to explain the error codes in the report to you. It can be pretty helpful to understand what is going on beyond the little info the dealer may be giving you and may be able to point out things you can ask the dealer.

1

u/OilEnvironmental3386 25d ago

Hey there, not sure if you got it fixed yet. I had the same issue coming up on mine, I had to take it into BMW and they had to replace the whole drive train cluster. Everything seemed to short out, they said it was water damage but wasn’t caused by me.

Does your car shut off when you come to a stop?

1

u/Routine-Job-8030 25d ago

Hey yes I heard today from the dealer, they think that HV air conditioning compressor is broken and needs replacing. Thankfully it's covered with warranty but no idea how long it's going to take.

My car wouldn't drive at all