Model Y Shuddering on Steep Downhill

[pureh2o]

I've noted this too. The conditions are:

• The beginning of a drive (close to home)
• Battery was not fully charged (~70%)
• Steep (20%) decline with stop sign at bottom.
• Occurs when the gas is disengaged.
• Shaking is substantial - similar to another poster that noted it feels like damage is being done.

 

[iustin]

@Gavinmac83, any news from the service/engineering department?

 

[Sidekick]

I've experienced this as well and can replicate it. Foot off the go-pedal and steep decline (driveway leading to garage). I'll record the date/time it next happens and send it into the service tech. Actually, I'll try and take a video of it next time I'm on that driveway (over Easter).

 

[iamnid]

I'm wondering if the recent "cold weather" software update has helped OP with this issue. I understand it is supposed to adjust the regen in cold weather. I can't report back re: my experience because I haven't been in cold weather recently and my Model Y is still on the factory software build from December 2020.

 

[gw5815]

Has anyone found a solution for this? I live on a steep hill so it happens daily!

 

[gw5815]

Has anyone found a solution to this? I live on a steep hill (San Francisco) so I experience it daily!

 

[Sidekick]

Has anyone found a solution to this? I live on a steep hill (San Francisco) so I experience it daily!

Do you think you could take a video (maybe one inside and one outside) and post it here? Then we can email our service people and let them know we also have this issue.

 

[gw5815]

Update -- if I turn on "Off Road" mode, the problem goes away.... which makes me think that it's the traction control system that is causing the crazy pulsating brakes. I have a SC appt Friday.

 

[gw5815]

I caught it on video last night and shared with Tesla SC --

You can see the regen braking pulsing on the screen.

 

[angus[Y]oung]

I caught it on video last night and shared with Tesla SC --

You can see the regen braking pulsing on the screen.

@gw5815 anxious to hear what they have to say!

 

[Sidekick]

Me too. I'll try and capture as well this weekend.

 

[Rippin1Gear]

So only under 15mph? Tried 25mph+ ? Regen does indeed look to be tripping out on the screen.
what software version?

 

[Sidekick]

So only under 15mph? Tried 25mph+ ? Regen does indeed look to be tripping out on the screen.
what software version?

Have you noticed how regen disengages at the very end of coming to a stop. So it slows the car down hard and then eases off at the very end? I bet what is happening is regen is slowing the car down to under that 'magic' speed, then the car speeds up because of the incline, then regen kicks back in. And it cycles back and forth as the speed crosses back and forth between that boundary.

 

[gw5815]

UPDATE: I visited the San Francisco service center this morning. My service manager told me that this is a familiar issue and that the next firmware will fix it. It's indeed a software issue related to regen braking. He told me that the firmware should apply in the next two weeks. My Model Y is only two weeks old and still has the factory firmware (2020.47.104). I'm wondering if 2021.4.12 is the version that fixes it. Is anyone running 2021.4.12 that saw an improvement?

I'm happy that it's a simple solution, but was a bit irked that they didn't call me prior to the appointment to save me the trip (waking up early; renting a car; taking off work; etc.). They had all of the details including my video (posted above) several days before. Oh well, at least a fix is coming.

 

[Sidekick]

2021.4.12 didn't do it for me today, so seems likely it's fixed.

 

[aidanbiggins]

Thank you guys for sharing the video and details about the firmware. Just got my MYP on Wednesday and was scared to death when this happened today.

 

[gw5815]

I finally received an update -- 2021.4.13 -- and the problem is now resolved. Yay

 

[Engineer3939]

We just took delivery of a new Model Y and experienced the severe shuttering on our first trip down our fairly steep driveway, it happens on almost all downhills. Took to Tesla for servicing, they found nothing, said they are working on a firmware fix, but no timeline on when it will be available. They told us it is not a safety issue, just drive it and do the best we can. We find the shuttering to be extreme and do not feel safe in the car. Anyone else feel the same?

 

[Sidekick]

We just took delivery of a new Model Y and experienced the severe shuttering on our first trip down our fairly steep driveway, it happens on almost all downhills. Took to Tesla for servicing, they found nothing, said they are working on a firmware fix, but no timeline on when it will be available. They told us it is not a safety issue, just drive it and do the best we can. We find the shuttering to be extreme and do not feel safe in the car. Anyone else feel the same?

Do you know which software version you're running? New deliveries start on an old firmware version and then receive an update about 2 weeks after delivery. I'm guessing you're not yet on 2021.4.X but will be soon.

 

[Rshephorse]

Not enough hysteresis on regeneration and you get an oscillation.
also putting in a plug for ScanMyTesla - gives you tons of information.
What would be interesting here is what is happening to the cars determination of "MaxRegen" - the maximum allowed regeneration- it kind of goes crazy and shuts down when you go down a steep hill. It could do this for battery or stability reasons. I"ve never gotten the shuddering but routinely get MaxRegen going from 84kw quickly down to 21Kw when I hit a steep downhill early in my commute.