[N8N]

Hi all, was on the highway yesterday and traffic was light enough to use cruise, but it wouldn't engage, when I hit the stalk the display would change but instead of displaying the set speed I just get two dashes. But I'm not getting any codes, warning lights, anything... I wasn't trying to engage it at a stupid fast speed either, if there's a max set speed (traffic was flowing at maybe 75-80ish, and I was just chilling in the right lane.) 2009 335i 6MT with about 82K miles. Any help appreciated, I rely on cruise often around town to keep me safe from the cameras, need it to work!

[AWTT335i]

Did you have DTC on or DSC off?

[N8N]

nope, wasn't playing around at all, I did cycle DTC on and off while driving b/c I just wanted to see what would happen (thinking wheel speed sensors most likely issue) but no ABS/DSC lights (or lights/warnings of any sort.) Maybe I just need to uninstall Cobb & take to dealer... grr...

[Transport3r]

do you have a piggyback?

[dfjaws]

Sometimes after turning DSC off it will do that for a bit, even after turning DSC back on. Try restarting your car or waiting a bit. Maybe that will help.

[Jeff@TopGearSolutions]

Could be a wheel speed sensor on the fritz. I was originally going to say tune but it's usually from the Piggy's. (Piggyback tunes)

[N8N]

I didn't have DSC off prior to noticing that the cruise didn't work... probably I have successfully used cruise more recently than I have turned off DSC. No piggyback, car is 100% bone stock save for various added factory accessories, VRSF FMIC, Cobb, and welded the flap open on exhaust because the rattle was annoying.

[N8N]

Originally Posted by Jeff@TopGearSolutions

Could be a wheel speed sensor on the fritz. I was originally going to say tune but it's usually from the Piggy's. (Piggyback tunes)

wouldn't WSS give me an ABS or DSC fault though?

[N8N]

And this is odd, I just got home and must have used the cruise at least 3-4x on the way, and it worked fine just as it always has up until yesterday.

[BMWM.D.]

The number 1 thing that usually causes this issue on these cars is a problem with the steering angle sensor or it's calibration. Usually it does cause the DSC/Brake warning lights, though. It could be an early sign of a failure. The SZL module is a pretty common failure.

Is your steering wheel straight and/or have you had an alignment done recently?

[N8N]

Yes, steering wheel is straight; no, haven't had an alignment done recently; I had one done last fall when I put my winter tires on (late October probably?)

If the SZL turns out to be the issue, is that significantly more difficult than replacing the multi-function switch on a late model American car? (I'm pretty good with the DIY.)

thanks again... (and keeping my fingers crossed that this was just a fluke)

[A418t81]

Does your clutch slip at all? If so, the ECU senses that and will not engage the cruise.

[N8N]

I certainly hope not! I haven't detected any slip, in any case... never taken the car down the strip, try not to throw any hard shifts unless I'm trying to get away from a moron driver who's gunning for me...

I have seen the cruise disengage while driving up a steep, twisty grade in the rain, I assume that that was from a tire slipping; this time was different though, it wouldn't engage at all in the first place, and I was driving down a straight, flat highway at constant speed (US-50 near Bowie, MD if you know where that is, you'll have to drive west to e.g. Ohio to find another highway that straight and flat!)

[Jeff@TopGearSolutions]

Originally Posted by N8N

wouldn't WSS give me an ABS or DSC fault though?

Not always and not always right away. I wouldn't go replacing it yet but take the tune out and see if it starts working again.

Since you said it's working again I would call it a fluke for now.

[n54door]

More than likely its the steering wheel sensor. It starts off as an intermittent issue. The problem with the sensor is it usually gets dirty over time. Check the boards for a DIY on how to clean it. Use Plastic polish on the sensor, it will be your friend.

[BMWM.D.]

Originally Posted by n54door

More than likely its the steering wheel sensor. It starts off as an intermittent issue. The problem with the sensor is it usually gets dirty over time. Check the boards for a DIY on how to clean it. Use Plastic polish on the sensor, it will be your friend.

That is the SZL module I mentioned. And yeah, there may be some low-buck fixes that don't require replacement. My best bet is a problem with the SZL/steering angle sensor, though.

[N8N]

well, I'm sitting here waiting for an interview... on my way over I stopped at a gas station and when I restarted, my radio was at 87.7 MHz... maybe my battery is finally going? This is the first sign I've had, but it is a 2009 and original battery...

[N8N]

well, I'm sitting here waiting for an interview... on my way over I stopped at a gas station and when I restarted, my radio was at 87.7 MHz... maybe my battery is finally going? This is the first sign I've had, but it is a 2009 and original battery...

[tunachris]

I recently had the clutch replaced on my E92, and the cruise control and hill assist features both stopped working after a few miles on the new clutch. Brought it back in to the dealer, and it turned out that due to the car being lowered a sensor was out of calibration. 5 minute quick fix and its been fine since.

[N8N]

Well, just coming back to this... I replaced the battery about 3 weeks ago and not a single issue since (touch wood...)