Parking Brake unexpected Release (MT)

[FLtrackdays]

Well, it looks like I may have a fix for mine. I had completely forgotten that I used Bimmercode to permanently disable the engine auto on/off feature. Today, Toyota engineers flew in, spent a few hours with my car, discovered the change, reverted it back to stock, and no more unexpected parking brake release when clutching out in neutral. They changed it back to how I had it, and the parking brake glitch came back. I verified this myself using Bimmercode. Got some egg on my face for sure but Toyota's been really nice about it.

I'll keep watching for the problem, though. I'm not 100% convinced that it's fixed. But at least now that we've figured this out, I can start screwing the car up in other ways, like swapping steering wheels, adding sways, etc.

Hope you nailed it! Mine does odd things (window 1/2 down, lane assist stuck on, etc.), I think I find the “fix” and then it’s back or never happens again. The mechanics that work on it say it‘s a BMW thing ?‍

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[morte]

That’s odd. I’ve coded out auto start/stop on mine and don’t have the issue…

I've also coded this out and haven't had an issue so far, ~3 months in

I suspect that in my case, it's some sort of bizarre bug in my ECU. I don't see why auto start/stop and the electronic brake should be related, and the brake glitch does not happen when I'm in Sport mode or when I turn auto start/stop off in Normal mode. It only happens when I've coded it out. There's a software bug still lurking somewhere in there. I hope that Toyota's engineers will keep looking for it, but it's more likely that my case will cause them to point the finger at Bimmercode and call it a day. Who knows, maybe it'll come back. I'm planning on keeping my car stock until at least early next year or until I wear out the clutch pedal trying to make the glitch surface again.

 

[Joker328]

it's more likely that my case will cause them to point the finger at Bimmercode and call it a day.

Why wouldn't they under the circumstances? If it happens when you used Bimmercode to code out auto start/stop and doesn't happen when you went back to stock, that's pretty strong evidence. The fact that it doesn't happen when you deactivate auto start/stop normally is further evidence that Bimmercode is the culprit. Now we need to hear from others that are experiencing this issue to see if they are also using Bimmercode.

 

[morte]

Why wouldn't they under the circumstances? If it happens when you used Bimmercode to code out auto start/stop and doesn't happen when you went back to stock, that's pretty strong evidence. The fact that it doesn't happen when you deactivate auto start/stop normally is further evidence that Bimmercode is the culprit. Now we need to hear from others that are experiencing this issue to see if they are also using Bimmercode.

@Spart said that the problem happened to him before he started using Bimmercode, and others have used Bimmercode without the problem happening. If I were debugging this, I'd want to look at the code and parameters for the version of the ECU that Bimmercode affects and diff it against the code of the version of the ECU that Bimmercode doesn't affect and see if there's anything that pops up there. That's assuming that the cars are running different versions, of course. If all of our cars are running the same code and the same params, on the same chips, then that's also a pretty big wtf. But it's not like that kind of thing doesn't happen all the time with software. I dunno how many times I've seen it at work, where two people try the same runbook while troubleshooting some bugwith some software or config, and get different results.

 

[lucky phil]

@Spart said that the problem happened to him before he started using Bimmercode, and others have used Bimmercode without the problem happening. If I were debugging this, I'd want to look at the code and parameters for the version of the ECU that Bimmercode affects and diff it against the code of the version of the ECU that Bimmercode doesn't affect and see if there's anything that pops up there. That's assuming that the cars are running different versions, of course. If all of our cars are running the same code and the same params, on the same chips, then that's also a pretty big wtf. But it's not like that kind of thing doesn't happen all the time with software. I dunno how many times I've seen it at work, where two people try the same runbook while troubleshooting some bugwith some software or config, and get different results.

Could it be the difference between using the Z4 selection for coding and the Supra selection when coding? Just throwing it out there.

Phil

 

[BMWAF]

Hope you nailed it! Mine does odd things (window 1/2 down, lane assist stuck on, etc.), I think I find the “fix” and then it’s back or never happens again. The mechanics that work on it say it‘s a BMW thing ?‍

I have experienced some of the issues you have described. Particularly Lane assist. While it was toggled off in iDrive, the lane assist would continue to bug me. I toggled it on and off a few times and it finally stuck. I did however, discover something interesting by accident. I suspect that some of these problems can be addressed by deleting the driver profile and building a new one. I say this because after I deleted my initial profile and created a new one, everything stuck without any more issues!

The profile holds far more detail than is obvious too. For example, after I had my cluster replaced the HUD no longer displayed the Cruise Control display but it did display in the main cluster. I liked this but to my horror, when I deleted my profile and created a new one, the HUD once again displayed the Cruise Control. I've since fixed it with BimmerCode but it goes to show that the driver profile is likely laden with loads of settings and data beyond what we can set manually in iDrive.

 

[FLtrackdays]

I have experienced some of the issues you have described. Particularly Lane assist. While it was toggled off in iDrive, the lane assist would continue to bug me. I toggled it on and off a few times and it finally stuck. I did however, discover something interesting by accident. I suspect that some of these problems can be addressed by deleting the driver profile and building a new one. I say this because after I deleted my initial profile and created a new one, everything stuck without any more issues!

The profile holds far more detail than is obvious too. For example, after I had my cluster replaced the HUD no longer displayed the Cruise Control display but it did display in the main cluster. I liked this but to my horror, when I deleted my profile and created a new one, the HUD once again displayed the Cruise Control. I've since fixed it with BimmerCode but it goes to show that the driver profile is likely laden with loads of settings and data beyond what we can set manually in iDrive.

Truth! I did that and even tried using only one key fob (forget where someone said each key is matched to a different profile - who knows). I do that every now and then. Rebuild the profile. The window thing is completely gone, for now. The traction control, VSC, lane assist (kaj) was talking about is more concerning to me on track. My rear brake light on the dash will flash in high speed corners. Chew thru the rear pads if I don’t mash that sucker for over 3 seconds, while driving. I can usually do it in the paddock. Anyway. You are right. That works for most things ?

*(my car was also more “upset” when she was lowered)*

 

[Spart]

@Spart said that the problem happened to him before he started using Bimmercode

Happened at the dealership on day one. I thought I was going crazy until I figured out how to replicate it. I checked my receipt for Bimmercode, and I had the car for two weeks before I changed anything.

 

[RyanA90]

Well, it looks like I may have a fix for mine. I had completely forgotten that I used Bimmercode to permanently disable the engine auto on/off feature. Today, Toyota engineers flew in, spent a few hours with my car, discovered the change, reverted it back to stock, and no more unexpected parking brake release when clutching out in neutral. They changed it back to how I had it, and the parking brake glitch came back. I verified this myself using Bimmercode. Got some egg on my face for sure but Toyota's been really nice about it.

I'll keep watching for the problem, though. I'm not 100% convinced that it's fixed. But at least now that we've figured this out, I can start screwing the car up in other ways, like swapping steering wheels, adding sways, etc.

A Toyota Engineer just contacted me about my problem. Before I schedule the appointment I’ll revert my BimmerCode auto start/stop back to stock and see if that solves the problem.

 

[RyanA90]

Ok, I reverted the auto start/stop to stock. So far so good! The PB does not release on start up at all. I'll monitor it every time I fire her up.

 

[bobby_tablez]

Bumping this thread as this appears to be a issue with my 2025 MT Premium I took delivery of last month. The issue is definitely related to pulling the parking brake with the engine running. Engine off, no issues.

I went ahead and also filed a complain to nhtsa.gov. The first time this happened I applied the brake and stepped out to unload some supplies from the trunk and had to jump back in the vehicle to save it from rolling away.

Now I've watched it disengage probably 25% of the time I park the vehicle.

Also, no bimmercode, completely stock car with only 700 miles.

 

[lucky phil]

Bumping this thread as this appears to be a issue with my 2025 MT Premium I took delivery of last month. The issue is definitely related to pulling the parking brake with the engine running. Engine off, no issues.

I went ahead and also filed a complain to nhtsa.gov. The first time this happened I applied the brake and stepped out to unload some supplies from the trunk and had to jump back in the vehicle to save it from rolling away.

Now I've watched it disengage probably 25% of the time I park the vehicle.

Also, no bimmercode, completely stock car with only 700 miles.

Hmm this has never happened to mine. I regularly back out of my garage onto my sloping drive put the car in neutral leave it idling pull the park brake, get out and kick a chock I have in the driveway under the front wheel cause I'm belt and braces type but the Ebrake has never released.
Phil

 

[fatedsorrow]

Happened to me... I feel dumb. I have PPF but not sure how much it protected. Getting a Maxton V1 to replace the lip.

 

[Eastwood]

So the go to move is to pull the E Brake after turning off the car?

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