2009 E91 RWD, New Tires, DSC Issues

mcclaskz · 09-06-2023, 12:15 PM

I have searched the issue, but haven't seen many definitive solutions. I bought my son a 2009 E91 328I RWD with stock 205/55/16 granny wheels all around. I then swapped them with my stock E90M3 18" staggered setup with 245/40/18 fronts and 265/40/18 rears. The TPMS were not functional and after rolling the rear quarter panel, I had no fitment issues or DSC issues. I recently put 235/40/18 fronts and 255/35/18 rears on the same wheels and immediately have DSC lights and codes going off. Just in case, I replaced the rear speed sensor, but nothing has changed. The 235/40/18 are 25.4" diameter and the rear 255/35/18 are 25". They are within 1.6%, so I did not think there would be an issue. The M3 fitment tires are much taller and higher % difference than what I just swapped to. What am I missing? Do I really need to swap fronts to 225/40/18?

mcclaskz · 09-12-2023, 09:24 PM

Since the car has 101k on it and speed sensors are cheap, I followed the codes and replaced both the front and rear speed sensors and the DSC issue went away entirely. I thought it was pretty unlikely both failed at the exact time I had new tires mounted, but who knows. Maybe this saves someone else in the future.

09-06-2023, 12:15 PM	#1
mcclaskz New Member 0 Rep 6 Posts Drives: E90M3,F25X3,G05X5,E91328i Join Date: Jan 2023 Location: Port City iTrader: (0)	2009 E91 RWD, New Tires, DSC Issues I have searched the issue, but haven't seen many definitive solutions. I bought my son a 2009 E91 328I RWD with stock 205/55/16 granny wheels all around. I then swapped them with my stock E90M3 18" staggered setup with 245/40/18 fronts and 265/40/18 rears. The TPMS were not functional and after rolling the rear quarter panel, I had no fitment issues or DSC issues. I recently put 235/40/18 fronts and 255/35/18 rears on the same wheels and immediately have DSC lights and codes going off. Just in case, I replaced the rear speed sensor, but nothing has changed. The 235/40/18 are 25.4" diameter and the rear 255/35/18 are 25". They are within 1.6%, so I did not think there would be an issue. The M3 fitment tires are much taller and higher % difference than what I just swapped to. What am I missing? Do I really need to swap fronts to 225/40/18?
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09-12-2023, 09:24 PM	#2
mcclaskz New Member 0 Rep 6 Posts Drives: E90M3,F25X3,G05X5,E91328i Join Date: Jan 2023 Location: Port City iTrader: (0)	Since the car has 101k on it and speed sensors are cheap, I followed the codes and replaced both the front and rear speed sensors and the DSC issue went away entirely. I thought it was pretty unlikely both failed at the exact time I had new tires mounted, but who knows. Maybe this saves someone else in the future.
	Appreciate 0 Quote