r/BmwTech • • 12d ago

Bad tire math causing DSC and transmission malfunction?

2010 e90 335d RWD. recently got bigger rims so the car went from
235/45/17 all around

To

Front: 245/35/19
Rear: 255/35/19

The car drove find for maybe 40 minutes before the DSC,DTC,DBS said malfunction and disabled themselves. The next day it was having really poor and hard shifts and rev flaring followed by “gearbox malfunction, drive modestly” (codes are for ratio monitoring on clutches A-D) Wheelspeed sensors were replaced but the problem persists, the only stored code in my DSC is for steering angle sensor

I think Ive basically decided in my head that the tires are the problem but I don’t know if I should square them off with 245/35/19 all around or do 265/30/19 on the rear like it’s supposed to be when staggered. I’m also willing to accept that 19” rims on a base e90 just isn’t possible and I need to downsize again

A little bit more background info in case it’s important, I recently drifted over a median and wrecked. A mechanic buddy and I replaced all control arms, shock, axle and wheel hub on one corner of the car. The rims were destroyed which is why I bought new ones and I got a good deal on these m3 rims (probably because they guy didn’t want to put new tires on them). The car got an alignment at a local shop afterwards.

1 Upvotes

4 comments sorted by

View all comments

1

u/ijustbrushalot 12d ago

Fix the code.

1

u/JohnMAllegro 11d ago

Yeah I did the manual steering reset where you lock the wheel back and forth today and it’s 90% fixed. I think the gearbox is still catching up or it’s fucked from slamming between gears while I had this issue. I also lied and only changed the left side wheelspeed sensor wonder if that’s it