IDK if this is somehow related to swapping winter tires for summers the other day, but that's the most recent thing I've touched on this car.
Today I was about 20 miles into a 450-mile drive when I noticed that the cruise control throttle adjustments were getting kinda jerky, and a minute or so later the stability control (ESP) gave a little dab of one of the front brakes, traveling straight on a straight freeway, at 75-ish mph. This disabled cruise control. So I set cruise again, and the same thing happened. I saw the ESP light flash a couple times as it happened. OK, hold the button for 5 seconds to disable ESP, no more false hits but also no more cruise control. Boooooo.
did not illuminate any fault lamps, and I don't know if it set any fault codes.
after first rest stop, I forgot to re-disable ESP, and I set the cruise as soon as I was blended back into turnpike traffic. After about 5 minutes of normal operation, again the cruise control's throttle adjustments became far too coarse, followed by another dab of one front brake, not enough to initiate a big yaw change, but enough to make me say berkeley that and disable ESP.
Driving 430 miles without cruise sucked.
WTF?
We can guess all day long, but you really need to try and check the codes. I know you are away from home, but that would be easiest.
Best would be INPA or a reader that can read BMW codes.
INPA dload
If you have a wireless dongle you can download bimmerlink.
The wheels/tires you swapped onto the car, if used, did they go on the same position they were on previously? Or at least equal wear on the same axle?
Do the reluctor rings get rusty on these newer cars? Does your car even have reluctor rings? This thread here makes it seem like some E90/1/2's do and some don't. It also says you can view live individual wheel speed data through the INPA which should tell you which corner to look at.
The first thing I'd do is take a look at all the wheel speed sensors. I have them get fowled by ferrous grit on my bimmers. We know how picky about sensor inputs these cars are.
+1 for wheel speed sensors. The stub axles on my E82 have reluctor rings, and they do get rusty - mine were sufficiently bad that they destroyed two speed sensors before I figured it out. I doubt yours is that bad, as you'd likely have warning lights if it were, but a loose connection or a fouled sensor could easily cause the problem.
cyow5
Reader
5/9/24 8:19 a.m.
My first thought was one of the umpteen valve control solenoids sticking, but I think looking at wheel speed sensors first makes sense since you seem to only have a problem when using CC. If the problem happened with AND without CC, then it could be on the engine side. But with CC only being a symptom, it looks to be on chassis side.
As you recently swapped tires, double check that they are the correct size first. I have seen cars with the aspect ratio off by 5 cause similar issues the the car thinking it's loosing traction.
Omg i have many words regarding BMWs from this era. Their stability control seemed to have no error checking.
I had a 328i with too little (not too much, but too little) air gap to a tone ring, and it refused to disable traction control. I was fighting the anti-throttle and the stuttering ABS activation for what felt like a minute, unable to exceed 15mph, until I could pull off the road. Probably was a minute as that stretch of road was a half mile long. It would NOT error out. Any other car, it realizes that there's a sensor issue and fails out the stability control. (Hey if three wheels are going 15mph and the VSS coming from Powertrain said we are going 15mph, then the other DRIVE wheel is probably also going 15mph...)
+2 I'd guess wheel speed sensors. They're easy to replace but yes rust "grows" on the toothed rings and can wipe out the sensors. I used a screwdriver to knock the rust down tooth by tooth on my 1series (and then a few miles later the other side wiped it's sensor). At least both sides were consistent.
Problem was repeatable on the 450-mile return trip, and seems to be sensitive to bumps such as transitions from overpass to road surface.
I will probably dig into this on Tuesday since, well, you know.
If you have a scan tool that can graph data, hook it up and see what it says. Watching a graph will be way easier than watching numbers. It should aim you at which wheel is angry, at least. Lots of Euros use a magnetic strip on the wheel bearing that can go bad, lots of cars also flex the wires going to the front wheels to death. If you can figure out which wheel is glitching, tug on the wires first, the dig deeper.
