Umm... My Model 3 driver power seat switches are drunk.

[TheMac19]

Hey crew - bizarro question here: My Model 3 seat seems to be drunk. When I use the power seat controls for the driver seat, very few of the functions work as intended, but instead, they're doing other things altogether. Here's the rough translation of what I tell the seat to do, and then what actually happens:

• The Seat Bottom Adjustment
  • slide forward = tilts the seatback recline forward
  • slide backward = the seat slides forward AND tilts the seatback recline forward at the same time
  • seat up/down works correctly
• Recline Control
  • recline forward = nothing happens
  • recline back = entire seat slides forward
• Lumbar controls all work correctly.

So... any ideas what is going on? The really odd thing is that this happened once last year, for about a week, and then had been working fine up until a couple weeks ago. As of now, the problem seems to persist, even though hard restarts. The seat is still controlled fine by the main brain, as selecting a driver profile moves the seat correctly - so it seems something is going on within the switch(es), not motors/wiring. Putting the seat into random high forward position makes no difference, so I don't think it's a wire strain issue.

I haven't tried pulling the trim to look a the back of the switched yet, so just curious if others have seen the same? Thanks!

 

[BigNick]

Sounds like the switches are defective, like some internal contacts have come loose and are completing the wrong circuits when activating the switches.

Or something conductive has found its way into the switch innards, or some of the wires have chafed through the insulation and are causing a (low voltage) short circuit.

I would think if it were a "VCLEFT" (or some other controller) issue, driver profiles would also be b0rked in addition to manual adjustments.

Should be replaced for free if you're still under the 4y/50K warranty.

 

[ph0ton]

This happened to me. I ended up trying to do recalibration but it failed. Despite it failing, the correct operation returned to the switches.

My seat settings wouldn't save too and this resolved it. My theory is that they changed the data structure to the seat settings at some point, and it gets locked into an old structure that causes these weird glitches. It won't save until you recalibrate because the old data structure doesn't pass some check, but it doesn't get replaced with a new one until you recalibrate.

 

[TheMac19]

Interesting - thanks. I’m on a rad trip at present, but will try recalibrating when I get home. I had just purchased a new seat control switch to swap in (haven’t installed it yet) but even better if recalibrating fixes it!

This happened to me. I ended up trying to do recalibration but it failed. Despite it failing, the correct operation returned to the switches.

My seat settings wouldn't save too and this resolved it. My theory is that they changed the data structure to the seat settings at some point, and it gets locked into an old structure that causes these weird glitches. It won't save until you recalibrate because the old data structure doesn't pass some check, but it doesn't get replaced with a new one until you recalibrate.

 

[TheMac19]

Update here... I tried the recalibration, and it seemed to work, but gave a "calibration failed, try again later" message at the end. But - the seat controls did not revert to normal thereafter. It was the same mixed up movement pattern.

Alas - I decided to swap the seat control module. In the meantime I'd actually bought two replacement modules: one newer used Tesla unit, and one off-brand replacement unit. Took the seat bottom side off and replaced my control module with the newer Tesla one and... the problem persisted. Ugh. The controls remained mixed up in the same way.

Since I'd already bought the generic one, I tried swapping that one in and... it worked! Curious if the two Tesla modules had somehow suffered the same failure, I swapped the purchased Tesla one back on, and now it worked fine too. So I swapped my original module back in and it, too, worked perfectly. WTF? Perhaps, as above, there was some software glitch and at some point in all the swapping the car reverted back to the right code? No idea.

Ultimately I decided to leave the newer Tesla module in place, and will see how it goes. My thinking is that perhaps there was something going on inside my original module that was causing the software issue? Who knows.

 

[ph0ton]

I remember having to do something else besides the recalibration, like put the seat back as much as possible, but I couldn't remember it so I didn't share it. I did get that recalibration failed message several times, until I fiddled around with it and it no longer gave me that error.

 

[TheMac19]

Interesting - I still get the calibration failed message, even though everything seems to be working 100% fine now. I'll try moving the seat through it's entire range of motion and see if that helps with the calibration. Though as long as the seat controls work, I'll be happy.

 

[ooglek]

I had an issue where my 2023 Model 3 Seat Position setting when synced through my Tesla Account profile would be completely WAAAY back when moving to my 2019 Model 3.

When I set the correct position on the 2019, the 2023 was WAAAAY forward.

Basically the calibration between the two cars was completely broken.

I calibrated the Driver Seat in the Service Menu in the car on the 2023, but on the 2019 I received an error: "Failed to perform calibration, please try again later" and would not adjust.

Tesla Mobile Service came out and was able to plug in a laptop into the 2019 Model 3 and run the calibration, et voila, no more sync seat position issues! However, I still am unable to calibrate the seats in the 2019 myself. The tech was unable to tell me why the seats would not calibrate. But no errors are thrown, no Hall Effect Sensor shorts, no control board issues. The tech also said that this is not something they can trigger remotely, so a tech would need to plug into the car and run calibration through their Tesla Service software.

Hopefully they fix it soon!

 

[TheMac19]

For whatever it’s worth, the seat switch gremlins are back, despite the new switch. Argh - the only possible thing I can imagine is an issue with the seat wire harness, so maybe I’ll swap that at some point. (It doesn’t look like a super fun job though…)

At lease the seat presets are still working as expected.

 

[ToobiasJ]

I’m having the same issue. Is there a way to contact Tesla other then the app?

 

[TheMac19]

Update!

So - I believe that I’ve finally found the fix, at least in my car: if anyone else suppers the same erratic seat control, try checking/tightening any plugs under the seat. One of mine seemed a bit loose, and indeed, after just pushing it further in, no more seat issues!

This also resolved an airbag warning light that had popped up. Easiest fix ever!

Just move the seat back, raise the front if you can, and push snug any connectors you can see. I think the orange one in me photo was the culprit.

After replacing the entire seat control module earlier, I feel a bit silly that the fix was so simple, but very happy it’s resolved!

 

[BigNick]

Odd that a loose connection would cause this unless there was some conductive gunk in there causing voltage to cross between wires.

I would think loose would just give intermittent movement in the intended direction you're pushing the switch, not make things upside down or otherwise movement not correspond to the switch.

 

[TheMac19]

Alrighty - happy to report back now with how things eventually worked out in this thread out for future reference:

Long story short, I decided to buy a Y, so I took the aforementioned Model 3 in to a service center to have it checked out. Even though things were working fine - I knew I was going to sell the car after getting the Y, so I really wanted to get to the bottom of the seat issue and make sure everything was perfect. So I made a service appointment, and they initially said the seat tested fine. Hmm... I wanted to be certain, so they offered to physically inspect the seat harness, but I'd have to pay for an extra hour of labor to do so. Fine by me.

Lo and behold, the tech did find an issue where the seat wire harness had been pinched (I think near the seatbelt) anchor, and the wiring had been slightly damaged, causing the erratic behavior, but only in certain positions. One new seat harness later, both issues were resolved 100% and the car got a clean bill of health. It cost a few hundred bucks - but is the only issue the car has had in almost 100,000 miles. Can't complain about that!

For reference, the new seat harness part cost $175, plus labor to install, and was listed on the invoice as below:

1ST ROW SEAT HARNESS ASSEMBLY - LEFT HAND - SEAT BELT REMINDER 1489060-02-G

Happy that it's all fixed properly. I also had a new 12V battery installed while I was there, so the car now has an official 100% clean bill of health from Tesla.