Multiple M3Ps dropping out of Track Mode for no reason

[Dangerous Fish]

A few of us were on our first track day of the new year yesterday.
5 x Model 3 Performances and at least 4 of them experienced something we've only ever had once or twice in the 4 years we've been taking them on track.
First off we kept seeing the lane departure warning message coming on every so often in all of them and don't remember getting that before in TM.
But worse than that, randomly and after a few laps there'd be a beep but no error message and it would drop out of track mode.

The cars having this issue were all on 2024.2.6 but another one not having it was on a lower version, so we're wondering if that has a bearing.
Nothing else was any different to the last time we were on track last year. Same wheels/tyres. Same USB drives.
Tried wheel resets, but didn't help.
When we unplugged the USB drives from the cars, TM worked fine with no drop outs so it seems to be something related to writing the data to the drive maybe?
Anyone else seen this?

ETA: I just saw the TM files from the car we thought was behaving but that one too was randomly dropping out of TM as some of the files just end halfway around a lap.
2 of them were on software 2023.44.30.14 it turns out, so not related to a recent update and a couple of the drivers told me they had this happen at the last track day they did at the end of last year.

Something must have changed for so many cars at one time to have this problem?

 

[RoadSoda]

My codriver had this happen to him mid run at an autocross this Saturday. Not sure what happened but it gave TC and SC errors that went away after resetting the car. Didn’t happen again for the next 7 runs that day. Am curious what the underlying cause is.

 

[Dangerous Fish]

We've had that happen before when we've been drifting them. Assuming your wheel speed sensor cables are intact (have you made sure the tyres haven't been rubbing them?) I think there may be a chance the software thinks something is up when all that's happening is the actual wheel speeds are varying more than normal because you're pushing the car hard through corners.

But what we had last week was nothing like that as it would drop out on a straight, for instance. And none of us got any errors, just the beep and TM is turned off. It's annoying because you have to come in and park to be able to turn it back on.

 

[gearchruncher]

My codriver had this happen to him mid run at an autocross this Saturday. Not sure what happened but it gave TC and SC errors that went away after resetting the car. Didn’t happen again for the next 7 runs that day. Am curious what the underlying cause is.

I've had this happen multiple times, very repeatably, if the tire size setting in the wheels menu is wrong. For me, always when turning near max G's, and on the power. It would clearly disable TC and SC, like you lost a wheel speed sensor, and persist until you put the car in park and got out, and then it would be fine.

I used to get this about 10% of my runs even on differnent surfaces and tires. I switched to the closest size tire diameter in the wheels menu, and I haven't had it happen a single time since, and that was about 2 years ago. What's interesting is it has something to do with driving style as well, as most Teslas at AutoX don't get this (although they were all slower than me )

Here's more details in the AutoX thread: Autocross- SCCA EV-X Class vs. SS

But that doesn't sound like what @Dangerous Fish is seeing.

 

[Dangerous Fish]

No, not the same. We tried wheel resets on the day as well.
We could have put it down to one of those random glitches we've all had, but this was multiple cars which have all used TM before and it happened almost every session that day with every car.
Something has changed in the Track Mode coding at some point. Whether it's connected with our drop outs I can't say, but I noticed looking through the .CSV files that the elapsed time used to start running as soon as START was pressed. That changed at some point so it's "0" until the car crosses the start/finish marker the first time.
That changed between September 2022 and May '23 based on my CSV files I've got on my USB drive.
At least this shows the code has changed over time and it makes me think there could have been a bug introduced causing drop outs in certain circumstances.

 

[Dangerous Fish]

Update - Tesla are looking into it. I reviewed some of the .CSVs from the cars with the issue and there are chunks of data missing and corruption at the end of the file sometimes.
Also it's seems unplugging the USB drive didn't stop it from dropping out, but maybe a bit less than when plugged in.

I still find it odd there aren't any other reports of what we experienced. Our cars are on the whole early ones made in Fremont, so shouldn;t be any hardware differences to early U.S. ones. Maybe there just aren't many owners using Track Mode?

 

[Dangerous Fish]

Here's what the CSV file looks like just before it drops out of Track Mode.
This is similar in all 5 cars we have had this problem with.
You can see there's a chunk of data missing and some zeros inserted.
A few lines aftere this the file ends when TM turns itself off.

We logged the problem as a service request in the app but Tesla just say "thanks for sharing but we don't have a repair".
It would help if anyone else having the problem also logs a service request because my feeling is there aren't enough owners using Track Mode anywhere in the world to make this a priority and the way it behaved last week it's broken.

 

[Dangerous Fish]

I've now looked at more CSV files from multiple cars and there is a general issue here with data being lost and/or corrupted.
I think most wouldn't notice it unless it was bad enough to cause TM to disengage, but it doesn't do that every time. It just seems to be doing it more now.

It would help a lot if anyone reading this could upload a Track Mode CSV file here so I can have a look and see if there is anything different.
I'm trying to narrow this down to a date when it started happening as I think it may tie in with a past Tesla software update, so a recent file and one from before September '23 would really help.

 

[Dangerous Fish]

@RoadSoda @gearchruncher Do you have any CSVs I could take a look at?

This shows how the resolution of the data has degraded over time. The first half of this graph is a clip from a track I drove 2022 and the second half from the same track in 2023. Look thru the CSV and you 'll see most of the data which is changing rapidly like throttle position, Power level, acceleration etc. has their values repeated in multiple cells all the way down the spreadsheet. It hasn't always been like that. My pre-2023 CSVs only had repeated values over 2 or 3 cells in each column. This may be a secondary issue, but just before TM disengages, I usually see a much longer block of repeated values and sometimes they're zeros.

 

[gearchruncher]

@Dangerous Fish - I would have some .CSV's over time, but I basically do AutoX, not road course stuff, so all my captures are pretty short. Would that still be helpful?

 

[Dangerous Fish]

@Dangerous Fish - I would have some .CSV's over time, but I basically do AutoX, not road course stuff, so all my captures are pretty short. Would that still be helpful?

Yes it would, especially if you have some spread between September '22 and May '23.

 

[Dangerous Fish]

How Track Mode files have changed through the years.
Anyone with a Ryzen Model 3P got a CSV file we can look at to see if it's related to the processing speed?
I've only been able to look at files from Intel Atom-based cars so far.

 

[Dangerous Fish]

Seems the big problem (TM disengaging) might be limited to Intel-Atom (pre 2022) cars using the lap timing feature.
The file corruption gets much worse once you cross the line for the first time and the timer starts going.
There may be other stuff happening in the background which also increases the processing load and causes TM to crash out.
I've now seen a file from a Ryzen car and although it's not free of the duplicated data blocks it's more like the 2022 example above.

I've been able to escalate this to Tesla UK now who will add it to their list, but I cant't think it'll be a priority for them especially with the connectivity and autopilot issues they've got.
If anyone gets TM dropping out on them, please mention it here though and report it via the service menu with the date/timestamp.

 

[DrZoidberg]

I had issues when lapping at a small track last summer, but almost never in point to point autocross. So, your theory above seems to make sense to me. 2018 m3p

 

[Dangerous Fish]

I had issues when lapping at a small track last summer, but almost never in point to point autocross. So, your theory above seems to make sense to me. 2018 m3p

Any files from that time you'd like to share?