Inaccurate temperature readings

[khyros]

Known issue. Or better still: known engineering **** up Elon Musk style.
They installed a heat pump in the revised 2021 Model3 but forgot to move the temperature sensor so when the heat pump is producing heat it is also blowing very cold air towards the sensor.

Musk's solution ? Rather than move the sensor elsewhere was to.. remove it and use GPS to find your temperature. Of course, if you are inside a car park, underground, and no internet, you have no temperature at all.

 

[khyros]

Thought I should follow this up.

It went in for the work above - replace the ‘active grill shutters’ - and all is good now with temp readings and AC behaviour. I was scratching my head how a non faulty temp sensor (they insisted the sensor was fine) could ever read lower than ambient. To hot, sure, if it’s mounted in an area that can trap hot air, but too low???

I guess I just wasn’t thinking heat pumps! Heat pumps of course will generate sub ambient temps in the system. So I guess the ambient temp sensor must be situated somewhere where the failure of these ‘active grill shutters’ exposes it to sub ambient temp air. Shutters fixed (they confirmed they were indeed stuck) and it’s all working correctly.

the only thing that has changed now is the weather, as it has warmed up your heat pump doesn't need to heat so much.
It's the same every year for me: initially would request service from Tesla when it was close to 0 degrees in January, by the time the appointment came temp had gone up to 10-15 so issue doesn't happen again until the following Winter

 

[Bouba]

My car is kept at the side of my house...mostly in the shadow....so it always reads colder than ambient...in fact my tyre warning light often goes on as well

 

[LiamPope]

Known issue. Or better still: known engineering **** up Elon Musk style.
They installed a heat pump in the revised 2021 Model3 but forgot to move the temperature sensor so when the heat pump is producing heat it is also blowing very cold air towards the sensor.

Musk's solution ? Rather than move the sensor elsewhere was to.. remove it and use GPS to find your temperature. Of course, if you are inside a car park, underground, and no internet, you have no temperature at all.

the only thing that has changed now is the weather, as it has warmed up your heat pump doesn't need to heat so much.
It's the same every year for me: initially would request service from Tesla when it was close to 0 degrees in January, by the time the appointment came temp had gone up to 10-15 so issue doesn't happen again until the following Winter

Hmmm. Well you're right about one thing for sure - the error was definitely most severe, like 10 degrees+ when the heat pump was running, e.g. heating cabin in the morning. So absolutely due to sub-ambient temp air blowing over the sensor. But I don't believe that is the usual and only possible behavior due to bad engineering. My previous winter with the car was entirely without this problem, and after these stuck shutters were replaced the problem was immediately fixed and we had a fair bit of cold weather left at that point (here in Norway) to verify. So I'm firmly of the opinion the erroneous behavior was due to a failure of hardware that was then repaired and not a permanent issue.

 

[khyros]

Hmmm. Well you're right about one thing for sure - the error was definitely most severe, like 10 degrees+ when the heat pump was running, e.g. heating cabin in the morning. So absolutely due to sub-ambient temp air blowing over the sensor. But I don't believe that is the usual and only possible behavior due to bad engineering. My previous winter with the car was entirely without this problem, and after these stuck shutters were replaced the problem was immediately fixed and we had a fair bit of cold weather left at that point (here in Norway) to verify. So I'm firmly of the opinion the erroneous behavior was due to a failure of hardware that was then repaired and not a permanent issue.

interesting. perhaps they found a way around but have not retro-fixed cars. can you share the service notes pls?

 

[LiamPope]

This is about all the exciting info I can get...

 

[carnutt]

This is about all the exciting info I can get...

View attachment 1043409

Thanks for the update, my car is out about 4-5 deg C so will add to my SC request. They may as well take a look while its in.