2020 M3P juddering and stopped mid-drive

[buss]

I've already engaged my local Tesla SC, but I feel like I could use any help or expertise avaialable here too to get an idea of what to expect, and so everything makes sense.

I recently had a loom, VCFRONT, and the main computer replaced as part of an issue, and the car was at Tesla SC for pretty much all of February 2024. All documented within this thread.

I've had the car back four days. Today I was in traffic, and instead of the right turn lane I indicated, steered the wheel left, and accelerated. There was no isue with power and then suddenly there was a violent juddering (enough to feel it and bounce me around) and a deep boom/knock that was in sync with the judder. It all happened very fast but I recall seeing the red PULL OVER NOW notice on screen. The car was left stationary blocking two lanes and not moving. Hazards on, got out to flag the oncoming cars, and got back in. On this attempt, I could drive the car and went the half mile home.

I am now sitting on a stack of errors. Here they are in chronological order.

- 15:22 | APP_w009
Automatic Emergency Breaking is unavailable
Feature may be restored on next drive
- 15:22 | APP_w264
L:ane Departure Avoidance features unavailable
Feature may be restored on next drive
- 15:22 | BMS_a170
Acceleration and top speed reduced
Performance may be restored on next drive
- 15:22 | DI_a139
Rear motor disabled - Avoid steep grades
Power reduced - Schedule service is alert persists
- 15:22 | DI_a063
Vehicle shutting down
PULL OVER SAFELY
- 15:22 | DIF_a126
Power reduced
Exiting and re-entering vehicle may restore operation
- 15:22 | DI_a172
Shift into D or R to drive
- 15:22 | DI_a189
Cannot shift gears - Accelerator pedal is pressed
Release the accelerator pedal and try again
- 15:22 | DI_a172
Shift into D or R to drive

The last few errors was probably me frustrated or under pressure, I'm happy to own those as that is a straightforward code.

I've tried to find a fault code database online but it doesn't look easy. And my unique combination of errors seem hard to find so far.

Has anyone got a link to a fault code database for Tesla? Or even better, any idea what to expect?

In any case, like the last thread I'll be chronicling how it unfolds.

 

[buss]

Since the issue, I drove 30 miles trying to replicate the issue overnight on isolated/quiet/service roads. I have tried:
- Hitting speed (up to 70mph)
- Harsh acceleration (basically flooring it from still and rolling)
- Generating Gs (not really scientific here, the test was "hooning it")

Couldn't get it to have the same issue again.

The only test remaining was to closer replicate the issue on the day - about an hour of sustained mixed driving:
1. A roads @ 70mph,
2. followed by a lot of traffic start-stop),
3. then some harsh acceleration
but I didn't have the time in the 3 days between reporting + dropping the car off.

All details passed to SC, though I feel they're not even reading it fully. Lets see how it goes.

 

[Birdsfan]

Please let us know the outcome.

 

[buss]

A hopeless update today.

The long story short is "we can't replicate the problem, so please take the car back and let us know if it happens again".

I am baffled.

Asked them "what information would replicating the issue provide, that isn't in the video/account/codes/exact times I provided?". I asked that twice and got the same regurgitated "we can't replicate it" response 3 times. Now the car is marked ready to pick up, and now actually "picked up" despite the fact its still at the dealer. Guess I'm going to follow up in person tomorrow.

 

[buss]

A mixed bag today, at least not with the worst possible outcome.

Went to collect the car today and the engineer was kind enough to make time to discuss the issue as I requested, after the last 2 promises from the previous case with another fella were never followed up. I won't go over everything as I took about 30 minutes of his time but he covered all my questions, made no empty promises, and was able to explain the ratrionale behind the process. Also if it did happen again it would not be a simple repeat of the same stuff - a 2nd occurrence would allow them to involve a master tech which might move things along.

Bottom line is their hands are pretty tied if they can't get the car to replicate the issue, or throw any codes. I don't think its ideal, but I see the process does have a flow for this kind of issue.

Anyway I agreed to take the vehicle back, Hopped in and made some seat adjustments, put it in drive...and the car threw 4 codes. I messaged him in-app and he responded he'd come out. Took a while, but when he did it looks like he'd been busy. Had a courtesy car ready (an equal spec 2020 Model 3 Performance), and said they'd re-investigate. He seemed very empathetic about the issue, having not even left the forecourt and having codes!

More updates to follow.

 

[Birdsfan]

Appreciate the updates, hope things get figured out.

 

[buss]

Appreciate the updates, hope things get figured out.

Cheers - fingers crossed. I put the thread up half hoping for any knowledge, but if not at least if someone else has the same symptoms there is some written reference. I'll be able to detail those exact codes later tomorrow, I took a video and I just need to rewatch it and copy them off as there were some new, some same.

 

[buss]

Couple updates and a hopeful conclusion. To make it easier to read I'll separate the posts.

First up, these are the codes that appeared once I put the car in drive on the Tesla SC forecourt.

- 12:04 | BMS_a170
Acceleration and top speed reduced
Exiting and re-entering the vehicle may restore operation
- 12:04 | BMS_a091
Unable to charge
Service is required
- 12:05 | RCM_a093
Safety restraint system fault
Service is required
- 12:05 | DIF_a126
Power reduced
Exiting and re-entering the vehicle may restore operation

The vehicle was not on charge, and the errors were all new. Helpfully they ticked over a minute change and we could easily see what was first.

We had some similar codes to the first occurrence, ie DIF_a126 but what was more interesting was the seemingly new and unrelated ones for charging and safety restraint. To his credit, the engineer immediately pulled out a courtesy car of equal spec and let me go on my way. I think its quite a stretch move given I didn't even buy the car from Tesla, so fair play.

 

[buss]

The same day in the evening, I got a message from the engineer I was dealing with that he'd likely found the source and would confirm tomorrow morning. The first person at Tesla to promise me a call back and actually do it - looks like the issue was bad internal grounding of the new VCFRONT unit when it was installed on my previous issue...so essentially human error. This would explain the interminttent nature of the issue, and how the spread of codes were seemingly random on the 2 occurrences that did happen.

I didn't chase for cab fare reimbursement for all the back and forth, seemed petty. I did forget to ask about the potential damage caused by the loose grounding - being thrown back and forth as the issue happened cannot be good for any components, but may be negligible.

Its only been a couple days I've had the car, last time the issue happened 4 days after receiving. But no issues experienced so far and I'm happy to have it back. I'm not sure its wise/allowed to namedrop the individuals and SCs involved (also for my sakes, its not going to be hard to identify me!) but I would say its not a unique trait to Tesla. I've had good and bad service from indy garages and car dealers before. Main thing is they did put it right.

 

[buss]

tl;dr
Got car back from SC, tonne of codes and dead-stop in road, hard to replicate, issue was bad internal ground in VCFRONT having recently been replaced.

New learnings

1. On the first report of an issue, Tesla will need to be able to observe/replicate the issue. If its intermittent, expect the car to be away for at least a week.
2. For an intermittent/hard to replicate issue, Tesla have a process in place. If they cannot replicate it in reasonable time/effort, you may get the vehicle back and if it happens again, it is escalated internally along their engineering chain. (This may change in future as we get more data).
3. Your charge and service data is not associated with your Tesla login, its with the car computer. I lost the metrics on charge/mileage and service request history when the computer was swapped out. Got those invoices manually emailed to me. I'd be curious to see what happens if you sell a car, do you lose all charge/economy data?
4. Don't let Tesla SC valet your car (at least in London). It came out dirtier than I dropped it off.

 

[HarleyW]

tl;dr
Got car back from SC, tonne of codes and dead-stop in road, hard to replicate, issue was bad internal ground in VCFRONT having recently been replaced.

New learnings

1. On the first report of an issue, Tesla will need to be able to observe/replicate the issue. If its intermittent, expect the car to be away for at least a week.
2. For an intermittent/hard to replicate issue, Tesla have a process in place. If they cannot replicate it in reasonable time/effort, you may get the vehicle back and if it happens again, it is escalated internally along their engineering chain. (This may change in future as we get more data).
3. Your charge and service data is not associated with your Tesla login, its with the car computer. I lost the metrics on charge/mileage and service request history when the computer was swapped out. Got those invoices manually emailed to me. I'd be curious to see what happens if you sell a car, do you lose all charge/economy data?
4. Don't let Tesla SC valet your car (at least in London). It came out dirtier than I dropped it off.

For #3, if you sold the car why would anyone care?

 

[buss]

For #3, if you sold the car why would anyone care?

The money I spend at a supercharger or home charging to me is my historic data. I feel like its a bit of an oversight for it to vanish once I sell a car.

Assuming I one day sell it, did I just lose all of those past savings? No, but I've lost reference to them now.

 

[jjrandorin]

@buss

Thanks for the recount, and also, thank you very much for the way in which the recount was done, including the summary etc to help others who may come across this later.

I am thanking you both as a regular member of TMC and owner of a model 3, and "officially" with my moderator hat on, on behalf of TMC.

Thanks again for sharing.

 

[buss]

You're very welcome mate. I've been on car forums for well over a decade and there no worse feeling than finding someone with the same issue you have, where the thread ends with "nvm sorted it"!

With Teslas being a relatively new tech I figure if we all pool anything we can learn, it benefits everyone.

 

[UsernamesRHard]

The money I spend at a supercharger or home charging to me is my historic data. I feel like its a bit of an oversight for it to vanish once I sell a car.

Assuming I one day sell it, did I just lose all of those past savings? No, but I've lost reference to them now.

If you use a third party app, like Tessie, you can export that information.

 

[buss]

If you use a third party app, like Tessie, you can export that information.

Cheers, I do already use it but am considering switching to Teslamate. It still seems like an oversight/shortfall on Tesla's part though. The fact you need a third party solution for this data should be a testament to this.

 

[jjrandorin]

Cheers, I do already use it but am considering switching to Teslamate. It still seems like an oversight/shortfall on Tesla's part though. The fact you need a third party solution for this data should be a testament to this.

Since Teslamate is self hosted, its my opinion that one is the best one to use if one is going to use any of these at all. I dont use any of them but if I was to use one, that would be the one.

I am not necessarily Mr. "tinfoil hat", however, with the way data breaches are now (not "if" but "when"), I tend to avoid extra logins to "stuff" if I can.