"Chassis function restricted" - Drive moderately

[SD ///M4]

Went out for errands yesterday, and after a few stops, I started up the car after the last stop and had this message on the iDrive display:

Chassis function restricted.
Drive moderately.
Consult service center.

I drove away and that's when I noticed that neither the M1 nor the M2 buttons were functional. The setting would display for a split second and then reset to normal. None of the console buttons worked either. The car appears to drive normally, but only in normal mode. The DCT shifts manually with no apparent problem There is a small triangle displayed in the lower right dash display. The error message can be displayed under Vehicle Status/Vehicle Info/Check Control, unless that car is turned off and back on, and then it displays "All systems OK".

Turning the car off and then back on clears the problem, but as soon as the car starts to move, whether an M button is pressed or not, the message reappears. Today I used the Torque app and my OBDLink LX dongle to scan for codes and it said that there were no codes stored in the ECU, so I backed out of the garage, got the message, scanned again, and still no codes.

The only thing that's changed on the car in a long time is that I installed a BMC air filter the other day which requires that the strut bar be removed to access and open the air filter boxes. I have the M Active Suspension and the rubber boots have to be moved aside to remove the strut bar. I did not disconnect or disturb the wires going into the top of the strut bar at all, but I went back today and double-checked to make sure that nothing was disconnected. My guess was that since it's a chassis error that it is somehow related to the suspension setting, but the throttle and steering buttons don't work either. The car has Ground Control Camber Plates and Dinan HAS springs, but those were installed by my independent mechanic almost 5 years ago and I haven't had any problems associated with them at all. My M4 is a 2016 with ~38,000 miles.

Anyone have any ideas?

[rmanm4]

You need a BMW specific scanner. You can also use the MHD app and scan errors for free. Generic OBDII scanner don't pick up everything.

[SD ///M4]

Originally Posted by rmanm4

You need a BMW specific scanner. You can also use the MHD app and scan errors for free. Generic OBDII scanner don't pick up everything.

I'll probably take it over to my independent guy on Monday. I wish I had gotten it together earlier today and had it done. Our club has a drive on Sunday so now I guess that I'll have to ride with my wife in her M3...

[rmanm4]

Originally Posted by SD ///M4

I'll probably take it over to my independent guy on Monday. I wish I had gotten it together earlier today and had it done. Our club has a drive on Sunday so now I guess that I'll have to ride with my wife in her M3...

Please invest in a BMW specific scanner either via OBD handheld, app/dongle based or better yet setup a ISTA+ on laptop! It's a must for every BMW owner!

Your error looks to be suspension based probably! Could be something simple like a speed sensor.

[icegrill]

Schwaben scanner is worth its weight in fine bullion.

[fiveohwblow]

Yeah I’m betting given it’s movement related it’s a wheel speed sensor or the like.

[jpy1980]

I had this issue and it could be a faulty wire to your EDC suspension and/or the accelerometer sensor on your EDC shock. It's probably not a permanent error, but a soft error that when triggered will come on. Hopefully it's as simple as replacing the sensor and/or wire, worst case, change out the shock.

Here's a long thread on the issue: https://f80.bimmerpost.com/forums/sh....php?t=1092996

I just decided to go with a static coilover system and coded out EDC.

Good luck!

[///MCollection]

I'm thinking most common would be wheel speed sensor or pulse generator as BMW call them but as said a scan will reveal all. Hopefully low cost what ever the issue

[noemon]

Get a BMW scanner, or the ISTA+ software.

This is probably nothing, possibly an accelerometer or one of their cables in the shocks or one of the valve cable.

Easy stuff you can replace on your own with a car jack.

[rmanm4]

https://www.amazon.com/AUTOPHIX-Diag...bb_marketplace

This is the one I recommend. You can even update it via usb cable. Its fast and effective. It can even register batteries and clear adaptations.

[SD ///M4]

Originally Posted by jpy1980

I had this issue and it could be a faulty wire to your EDC suspension and/or the accelerometer sensor on your EDC shock. It's probably not a permanent error, but a soft error that when triggered will come on. Hopefully it's as simple as replacing the sensor and/or wire, worst case, change out the shock.

Here's a long thread on the issue: https://f80.bimmerpost.com/forums/sh....php?t=1092996

I just decided to go with a static coilover system and coded out EDC.

Good luck!

Thanks for that link, I read through it today That sure seems to the same problem I'm experiencing.

I'm going to take my car to my independent tomorrow and run the codes and see if he's seen this on other F8x cars.

[SD ///M4]

Originally Posted by rmanm4

https://www.amazon.com/AUTOPHIX-Diag...bb_marketplace

This is the one I recommend. You can even update it via USB cable. It's fast and effective. It can even register batteries and clear adaptations.

Thanks for the link. I've looked at BMW scanners off and on for over 5 years but I just can't figure out which one to get. I looked at this one and also a Foxwell, but they both seem to have their fair share of 1-2 star reviews on Amazon.

Have you used this one on your M4? I'd also like to use it on my 2006 E85 Z4 M Roadster.

[rmanm4]

Originally Posted by SD ///M4

Thanks for the link. I've looked at BMW scanners off and on for over 5 years but I just can't figure out which one to get. I looked at this one and also a Foxwell, but they both seem to have their fair share of 1-2 star reviews on Amazon.

Have you used this one on your M4? I'd also like to use it on my 2006 E85 Z4 M Roadster.

I've used it on my e70, e90 and on my F82. Read and clears errors perfectly and also shows live data from each module. I wouldn't rely on it for more then just that!

[fiveohwblow]

Originally Posted by rmanm4

I've used it on my e70, e90 and on my F82. Read and clears errors perfectly and also shows live data from each module. I wouldn't rely on it for more then just that!

Is the functionality the same as the schwaben? Appears so… if so, I’ve used mine to reset adaptations after a trans/clutch/smg pump replacement on my track car. Quite useful.

[rmanm4]

Originally Posted by fiveohwblow

Is the functionality the same as the schwaben? Appears so… if so, I’ve used mine to reset adaptations after a trans/clutch/smg pump replacement on my track car. Quite useful.

I've registed battery on e70 with it. I also reset adaptations my on F82 with it but it said it fail, after you accept the car turned off and on restart you can feel it actually did reset. I had to reset it due to intake upgrade, as it I was getting air rich error, after a reset (even though it said failed) the error never returned and car runs perfect. So I do believe it works well. I just rather do the more complicated things via ISTA+ where you get confirmation and see values after reset.

[SD ///M4]

I finally got the car to my independent guy this afternoon and he confirmed that the RF accelerometer was throwing the fault. He thinks it was just coincidence that this happened after I removed the CF strut bar to replace the air filters, especially since it didn't happen immediately after. Prior to this I double-checked the wiring and unplugged and replugged the cables for the strut towers, even though I didn't disconnect them originally when I replaced the filters. This changed something, because now I can individually change the throttle and steering settings, and select MDM. The chassis status is blanked out in the dash display though. I've been driving around with the chassis in Sport+ for 9 days and that's too much for street driving (I also have Dinan HAS).

I have an extended warranty, so I've made an appointment at my dealer to have it checked out and replaced on Monday. I'll post an update next week.

[SD ///M4]

I took my M4 to the dealer on Monday and it was ready yesterday afternoon. Kind of surprised that it took that long, but I'm guessing that the parts weren't in stock.

As diagnosed by my independent, it was the RF accelerometer. They replaced the right front "accelerating sensor" (accelerometer), p/n 37-15-6-871-465 ($121.46 at getbmwparts.com) and the "cable for wheel acce" (cable for wheel acceleration sensor), p/n 31 30 7 850 609 ($23.96). Everything seems to be working correctly again. As my independent indicated, it was just coincidental that this part failed shortly after moving the strut boots and removing the strut bar to replace the air filters.

Since I have an extended warranty, my total cost was the $50 deductible. I got to drive a brand-new (2900 mi), pretty loaded 2021 G30 M440i for a few days. iDrive (7.0) sure has changed in the 5 years since I got my M4!

One option that it had that I didn't see on the BMW build site was seat ventilation for the front seats. Definitely something that I would want.

[andrei.m4]

I have only one conclusion after running my m4 100k miles, acceleration sensor not fail, the cable fail somehow without exterior visible damage. Thats why they replace also the cable, thats why some members on the forum not solved the problem with only replacing the sensor because sensor not fail, cable fail. On the right side i paid sensor and cable also, but on the left i just replaced the cable.

[rmanm4]

Everyone should replace the cable on both sides every 4 years as preventative maintenance! Its a cheap part that should be replace every 4 years or on a break job cause you right there!

[phefner]

Had the same error on a track day at Road America last weekend with my 2016 M3. Using it in M-Mode Sport-Plus Chassis. Going into turn 1 at 150mph. Hit the braking zone and bam, Chassis Function Restricted. Was the 3rd lap of the first session.

I've had the car for 4 weeks and been prepping it for track duty (50K on the clock). ALL fluids and oils replaced, new brake rotors, Hawk DTC 60 pads, & stainless brake lines. Indy shop I used was able to quickly diagnose.

We now have 2 new acceleration sensors and cables. Probably a good idea to put these on a replacement schedule.

Will see if these can survive my next track weekend over Labor Day weekend with the PCA at Road America.