Can't turn DSC Off

[evoiii90]

Hello everyone...

Hoping someone have seen this before and can shed some light on how to fix it...

Problem: Can't turn the DSC off after pressing the console DCS button. Nothing happens, ie, the traction control icon on the dash doesn't lit amber after pressing for 1 second or more.

Did some diagnosis including reading error codes with ISTA-D and none showed up for the DSC nor DME. Used ITSA-D to also check if the DSC unit "sees" the button being pressed and it doesn't, except for maybe 0.5 sec or less. Swapped the three button assembly from another M3 and nothing. Tried my cars buttons on another car and they're working. Checked the main wire from the button to DSC unit and it's good. Bottom line, traction control is always on.

Got my track built 2011 M3 with DCT back in 10/2020. Car has a full cage, no interior, MCS 2 Way adjustable on Coil overs and StopTech's ST60 in the front. Engine DME and DCT are stock, still have the cats since the car is registered for street usage, so I drive it to/from the track. Car doesn't have the stock steering wheel so I cannot engage the M-Button either.

Haven't had any issues since I got the car until last weekend when I was at ButtonWillow and tried to turn it off for my first session. I couldn't, went out either way but because the suspension is really stiff, it was setup for COTA where it was built, then traction control was engaging on every turn reducing the power dangerously, specially if someone was somewhat close behind. So I aborted the day and went back home after trying to diagnose it with a generic OBC scanner.

After a suggestion from a racer, today, I disconnecting Yaw sensor under the drivers seat and now DSC is totally off since it cannot get all the signals it expects, but since I drive the car to/from track, I would like to figure out what's going on.

Any suggestions / ideas ??

[dparm]

Sounds like the DSC computer is faulty (either hardware or software), if you have confirmed that the button and wiring is good.

I would get a copy of the factory service manual, which is what the BWM techs use, and follow the diagnostic flowchart. Arbitrarily replacing parts is not the optimal approach.

[evoiii90]

As you probably know, there are no printed service manuals for these E92s, at least I never heard of them, it's all based on on ISTA-D diagnosis process, and since there are no error codes, ISTA-D is not presenting a diagnosis plan, but I'll check again and see if I missed something on the options the software gives to diagnose the DSC controller.

As for arbitrarily replacing parts, I'm not. Using ISTA-D I saw the DSC OFF button wasn't giving a signal the software could/should see, which lead to the initial conclusion the button itself was the culprit. But it turned out the button in my car is ok since it didn't work with another car's button, and installing my car's button in the donor car worked, so it's not the button assembly.

Thanks for the input either way.

Originally Posted by dparm

Sounds like the DSC computer is faulty (either hardware or software), if you have confirmed that the button and wiring is good.

I would get a copy of the factory service manual, which is what the BWM techs use, and follow the diagnostic flowchart. Arbitrarily replacing parts is not the optimal approach.

[dparm]

Sorry, forgot that the diagnosis process is done with ISTA-D. Have been out of the BMW scene for a few years. :-)

[Mog-10]

I had this problem. I unhooked the battery for a few hours and it resolved itself.

[evoiii90]

Interesting... I disconnected the battery too, but only for a couple of minutes and it didn't work, not for a longer period like you did. Did you by any chance tried for a couple of minutes too before leaving disconnected for a couple of hours ??

Originally Posted by Mog-10

I had this problem. I unhooked the battery for a few hours and it resolved itself.

[Mog-10]

Originally Posted by evoiii90

Interesting... I disconnected the battery too, but only for a couple of minutes and it didn't work, not for a longer period like you did. Did you by any chance tried for a couple of minutes too before leaving disconnected for a couple of hours ??

First I had my power button would not turn off and was not showing on the dash and I had disconnected the battery for a few minutes and that did not work and so I let it sit for a few hours and that worked like a month later dcs would not so I just repeated removing it for a few hours and it worked . Both times the car had sat for a minimum of a month. Weird things seem to happen if I let it sit. Also use to get weird air bag and dcs/anti lock warnings when I would get axel hop then moments later they would go away. I don't get any axle hop anymore even when it's wet😁.

[evoiii90]

That's even more interesting behavior, Lol....

Since my car is basically a race car as probably yours is, I only use it once or twice a month like you, so it also sits for somewhat long periods without being fired up, but it's always on a battery tender, so it shouldn't be low battery voltage related, although maybe it is since I know weird things happen when the battery voltage and/or charging voltage is not where it's supposed to be.

Will try your method and see what happens since on my car it's pretty easy and because it has a master battery switch, so I'll just turn it off tonight and leave it off the whole night.

Will report tomorrow after I first reinstall / reconnect the Yaw sensor since I took it out as a last resort...

Thanks for the tip...

Ohh, and was trying to do additional wiring harness diagnosis using ISTA-D's diagrams, but for some reason they're incomplete for the button cluster assembly and it's connector, ie, S0241 and X4444 respectively. The diagrams only show one pin for the actual DSC OFF button, one for a signal to the DME and ground, nothing else even though there are 10 pins on X4444 but only 8 cables and by doing a text search for S0241 and X4444, which should at least show up also for EDC and DME modules since there are two more buttons beside DSC OFF.

And this is with two versions of ISTA-D, mine, which is somewhat old, and the one from my buddy's indy shop which is up to date since he pays BMW's subscription. Go figure, go to love incomplete diagnosis info when you need it...

Originally Posted by Mog-10

First I had my power button would not turn off and was not showing on the dash and I had disconnected the battery for a few minutes and that did not work and so I let it sit for a few hours and that worked like a month later dcs would not so I just repeated removing it for a few hours and it worked . Both times the car had sat for a minimum of a month. Weird things seem to happen if I let it sit. Also use to get weird air bag and dcs/anti lock warnings when I would get axel hop then moments later they would go away. I don't get any axle hop anymore even when it's wet😁.

[Redd]

If you have iDrive, try to use the M button settings to disable DSC. See if that works. If it does then at least you know the issue may not be with the ECU.

[Mog-10]

Originally Posted by evoiii90

That's even more interesting behavior, Lol....

Since my car is basically a race car as probably yours is, I only use it once or twice a month like you, so it also sits for somewhat long periods without being fired up, but it's always on a battery tender, so it shouldn't be low battery voltage related, although maybe it is since I know weird things happen when the battery voltage and/or charging voltage is not where it's supposed to be.

Will try your method and see what happens since on my car it's pretty easy and because it has a master battery switch, so I'll just turn it off tonight and leave it off the whole night.

Will report tomorrow after I first reinstall / reconnect the Yaw sensor since I took it out as a last resort...

Thanks for the tip...

Ohh, and was trying to do additional wiring harness diagnosis using ISTA-D's diagrams, but for some reason they're incomplete for the button cluster assembly and it's connector, ie, S0241 and X4444 respectively. The diagrams only show one pin for the actual DSC OFF button, one for a signal to the DME and ground, nothing else even though there are 10 pins on X4444 but only 8 cables and by doing a text search for S0241 and X4444, which should at least show up also for EDC and DME modules since there are two more buttons beside DSC OFF.

And this is with two versions of ISTA-D, mine, which is somewhat old, and the one from my buddy's indy shop which is up to date since he pays BMW's subscription. Go figure, go to love incomplete diagnosis info when you need it...

Mine is not a race car. It just sits some times.

[evoiii90]

Unfortunately and as I mentioned on my original post, car doesn't have the stock steering wheel, so even though I can access iDrive's M button settings, I cannot engage the M button because, well, it doesn't exist.

If I could hack into the iBus and send an M button digital signal, which is basically done through software like the steering wheel can, then maybe I could test this, but will really need to research this and/or talk to someone who has hacked into the iBus commands and protocol.

Originally Posted by Redd

If you have iDrive, try to use the M button settings to disable DSC. See if that works. If it does then at least you know the issue may not be with the ECU.

[evoiii90]

Finally tried this and unfortunately it didn't work. Battery was disconnected all night but still can't turn DSC off after reconnecting it and testing.

I also drove the car earlier today without the Yaw / DSC sensor being connected, and even though DSC is off since the controller can't determine what to do without the sensor, I noticed two things:

- Can't engage the DCT highest settings (7th ??), the one that appears when DSC is off.
- DCT transmission goes into somewhat of a default mode, in which for example in first gear engine won't rev up the rev limiter, it'll shift to 2nd gear way before.

There might be some other things the DME or DCT won't allow, but couldn't test further on the street.

Now trying to diagnose further, but maybe the DSC unit itself is faulty...

Originally Posted by Mog-10

First I had my power button would not turn off and was not showing on the dash and I had disconnected the battery for a few minutes and that did not work and so I let it sit for a few hours and that worked like a month later dcs would not so I just repeated removing it for a few hours and it worked . Both times the car had sat for a minimum of a month. Weird things seem to happen if I let it sit. Also use to get weird air bag and dcs/anti lock warnings when I would get axel hop then moments later they would go away. I don't get any axle hop anymore even when it's wet😁.

[Mog-10]

I wish that would have worked for you. I hope you find a solution.

Originally Posted by evoiii90

Finally tried this and unfortunately it didn't work. Battery was disconnected all night but still can't turn DSC off after reconnecting it and testing.

I also drove the car earlier today without the Yaw / DSC sensor being connected, and even though DSC is off since the controller can't determine what to do without the sensor, I noticed two things:

- Can't engage the DCT highest settings (7th ??), the one that appears when DSC is off.
- DCT transmission goes into somewhat of a default mode, in which for example in first gear engine won't rev up the rev limiter, it'll shift to 2nd gear way before.

There might be some other things the DME or DCT won't allow, but couldn't test further on the street.

Now trying to diagnose further, but maybe the DSC unit itself is faulty...

[Wadzii]

Originally Posted by evoiii90

Finally tried this and unfortunately it didn't work. Battery was disconnected all night but still can't turn DSC off after reconnecting it and testing.

I also drove the car earlier today without the Yaw / DSC sensor being connected, and even though DSC is off since the controller can't determine what to do without the sensor, I noticed two things:

- Can't engage the DCT highest settings (7th ??), the one that appears when DSC is off.
- DCT transmission goes into somewhat of a default mode, in which for example in first gear engine won't rev up the rev limiter, it'll shift to 2nd gear way before.

There might be some other things the DME or DCT won't allow, but couldn't test further on the street.

Now trying to diagnose further, but maybe the DSC unit itself is faulty...

Did you ever end up finding a solution to this?

[omgzirra_exe]

Originally Posted by Wadzii

Did you ever end up finding a solution to this?

friend of mine had same issue, just had to replace the DSC button the whole thing, not just the cap.

[evoiii90]

Yes, the independent shop I use figured it out. It turned out to be the JBE (Junction Box Electronics) module, which is somewhat of a signal traffic controller between other modules in the car. What was happening is that there were some signals the DCT module wasn't getting, so it'll block the DCT from being deactivated.

Some info about the JBE at https://bimmerscan.com/bmw-junction-box-jbe/

The shop installed a new JBE and everything started working again. That was 6 months ago and it's still working. The DCT unit itself was fine.

Originally Posted by Wadzii

Did you ever end up finding a solution to this?