Model 3 powered trunk retrofit causing intermittent cabin climate control system failure

[bnone]

Do you have the Tesla Powered Trunk retrofit?

yep. and I also had all those HVAC issues with numerous service center visits, until they've disconnected the CANBUS. But it looks like the car started to behave overnight, maybe it fell asleep and woke up in a good mood lmao.

Jokes aside, it looks like the car needs to be almost completely shut down for the trunk to start working, so 12V and HV needs to be disconnected. I tried to completely disconnect the liftgate ECU, it didn't do the trick, so some other ECU needs to be restarted. Another question is whether the car will go asleep if the liftgate ECU canbus is still connected. I had to connect it back to update the ECU SW, but disconnected it afterwards. Will reconnect it later to check if the original issue with the car unable to go asleep is resolved.

 

[Scelto]

I had a call from the SC that they had an early access firmware update to fix the problem. I was reluctant to take anything early access, but was persuaded to give it a chance.

I dropped my car off and it ended up being with them for two and a half days, both because of unexpected problems getting access to the right firmware build and because they now apparently only have 5 techs instead of the previous 11 following the mass layoffs - doesn't bode well for future ownership...

Anyway, I got it back and two days in everything seems fine - no spurious PCM messages, no phantom drain and the tailgate works as well as it ever did

The version is reported as 2024.3.25 but apparently they flashed the tailgate module separately so I can't say with confidence that this version contains the fix.

I was concerned that a future update might overwrite the "special" version on the module, but the SC manager told me that all future versions would contain it anyway, so taken at face value anything later than 3.25 (and maybe 3.25 itself) should have the fix.

 

[justsomeguy]

I had a call from the SC that they had an early access firmware update to fix the problem. I was reluctant to take anything early access, but was persuaded to give it a chance.

I dropped my car off and it ended up being with them for two and a half days, both because of unexpected problems getting access to the right firmware build and because they now apparently only have 5 techs instead of the previous 11 following the mass layoffs - doesn't bode well for future ownership...

Anyway, I got it back and two days in everything seems fine - no spurious PCM messages, no phantom drain and the tailgate works as well as it ever did

The version is reported as 2024.3.25 but apparently they flashed the tailgate module separately so I can't say with confidence that this version contains the fix.

I was concerned that a future update might overwrite the "special" version on the module, but the SC manager told me that all future versions would contain it anyway, so taken at face value anything later than 3.25 (and maybe 3.25 itself) should have the fix.

This is great news. My car is on 2024.3.25 but the non special version. I guess I'll plug the connector back in before I do the next update and hope for the best.