Well there’s a thing, sudden unintended acceleration just happened to me

[fiveten]

Kind of related...I had an instance where my model 3 failed to engage regenerative breaking multiple times.

I had just got my tires changed at a tire store and my car had been sitting out in about 45 degree temperature for a few hours.
My car was around 50% charged.

I got on the feeder road and when I got to a stoplight, i lifted my foot off the accelerator and the car did not start slowing down/regenerating like it would normally do.
I came to a stop using the brake...and then when the light turned green i started driving and the next time I tried to start slowing down and lifted my foot off the accelerator....the car did not start slowing down or regenerating like it normally does either.

Later on in the drive, it started acting normal for most of my drive back home.

However, when I got back in my neighborhood I messed around with it some more and noticed it was not working again and took some pictures of my touchscreen with my foot being on the completely off accelerator and the regeneration not engaging.

There were no messages or warnings on my screen telling me regeneration was limited...and even when regeneration is limited I've always had the car slow down/regenerate at least some when my foot is completely off the pedal.

Tesla told me that they pulled my logs and that when it the battery is cold regeneration doesn't always work....but on the phone they couldn't give me any actual details and they are having their techs look back at it again. I've driven my car in much colder temperatures with the battery being much colder and there was always some regeneration.

My theory is that my accelerator pedal is sticking sometimes....

 

[MP3Mike]

had just got my tires changed at a tire store

Changing your tires can cause loss of regen while your car learns the new traction profile. (I'm pretty sure that the manual covers this.)

 

[fiveten]

Changing your tires can cause loss of regen while your car learns the new traction profile. (I'm pretty sure that the manual covers this.)

Thanks, let me check...that's a much better possible explanation than the tech was trying to tell me!

 

[hybridbear]

If what you describe actually happened your car is broken and you should open a service ticket immediately.

I've been away from TMC for a few weeks. Here is a link to a video I made. If I press deep down on the brake pedal then there is no power to the motors. But if you are not flooring the brake pedal then the car will still accelerate, like in the video. When I made this video I was in a parking garage so I could not see how fast the car would accelerate with the brake pedal pressed, but you can see that the brake lights never turned off & that the alarm did not continue to beep even while both pedals were pressed for an extended period.

 

[MP3Mike]

I've been away from TMC for a few weeks. Here is a link to a video I made. If I press deep down on the brake pedal then there is no power to the motors. But if you are not flooring the brake pedal then the car will still accelerate, like in the video. When I made this video I was in a parking garage so I could not see how fast the car would accelerate with the brake pedal pressed, but you can see that the brake lights never turned off & that the alarm did not continue to beep even while both pedals were pressed for an extended period.

The NHTSA investigation document describes how the feature works:

In addition, all subject vehicles have Tesla’s brake override logic that will cut motor torque if the brake and accelerator are applied at the same time. If the accelerator pedal is pressed before the brake pedal (or within 100 milliseconds of brake pedal), motor torque is reduced to zero. If the brake pedal is pressed and then the accelerator pedal, motor torque is limited to 250 Nm and motor power is limited to 50 kW. In the latter condition, the driver should be able to hold the vehicle stationary regardless of accelerator pedal position with 85 to 170 N (19 to 38 lbf) of brake pedal force, depending on the platform.

Are you seeing behavior that is in conflict with that?

 

[dmurphy]

Which reminds me, I wonder if those people who used to drive manuals have had an easier time adapting to regen, because of their experience with engine braking.

I’m going to go out on a limb and say yes. My dad’s driven commercial vehicles of all shapes and sizes his entire career and immediately took to it when I let him drive. Felt wholly natural to him.
I also have a buddy who drives a manual TSX daily. Same thing - he said it just felt completely natural ... and the only thing he’d consider aside from a manual. So he’s due for a Y, probably next year.

 

[hybridbear]

The NHTSA investigation document describes how the feature works:

In addition, all subject vehicles have Tesla’s brake override logic that will cut motor torque if the brake and accelerator are applied at the same time. If the accelerator pedal is pressed before the brake pedal (or within 100 milliseconds of brake pedal), motor torque is reduced to zero. If the brake pedal is pressed and then the accelerator pedal, motor torque is limited to 250 Nm and motor power is limited to 50 kW. In the latter condition, the driver should be able to hold the vehicle stationary regardless of accelerator pedal position with 85 to 170 N (19 to 38 lbf) of brake pedal force, depending on the platform.

Are you seeing behavior that is in conflict with that?

Yes. If the accelerator is pressed first then the motor power is cut to zero. But if the brake is pressed first then motor power is not limited to 50 kW. Two additional videos are linked below which I just filmed this afternoon. In both videos the motor power reached around 150 kW according to the dash display. According to Scan My Tesla logging the power reached 146 kW peak

 

[DopeGhoti]

Which reminds me, I wonder if those people who used to drive manuals have had an easier time adapting to regen, because of their experience with engine braking.

An intriguing hypothesis. I had driven stick by preference before I spent years in automatic CVT hybrids, and I was delighted to be able to turn off Creep on day one; Hold mode was even better.

 

[Gasaraki]

I’m going to go out on a limb and say yes. My dad’s driven commercial vehicles of all shapes and sizes his entire career and immediately took to it when I let him drive. Felt wholly natural to him.
I also have a buddy who drives a manual TSX daily. Same thing - he said it just felt completely natural ... and the only thing he’d consider aside from a manual. So he’s due for a Y, probably next year.

Yeah, that could be... I drove a manual WRX before and the Model 3 was normal wasn't a big change for me. All I remember was when I first had my car delivered and then I took it out for my first drive, when I stepped on it on the first major road... I'll never forget that feeling of your first time...

 

[Apone]

Agree that when the regen is strong it feels like my previous manual cars and I love it. What’s not great is the winter when that regen goes away! Hard to know what to expect when you lift off the go pedal sometimes. I prefer the strong regen feel.

 

[tomas]

Agree that when the regen is strong it feels like my previous manual cars and I love it. What’s not great is the winter when that regen goes away! Hard to know what to expect when you lift off the go pedal sometimes. I prefer the strong regen feel.

Yeah, I wonder if there isn’t some way they could regenerate even if cold, but slough off the generated current somehow rather than recharge the battery with it. So we get consistent strong regenerative braking. .

 

[hybridbear]

The NHTSA investigation document describes how the feature works:

In addition, all subject vehicles have Tesla’s brake override logic that will cut motor torque if the brake and accelerator are applied at the same time. If the accelerator pedal is pressed before the brake pedal (or within 100 milliseconds of brake pedal), motor torque is reduced to zero. If the brake pedal is pressed and then the accelerator pedal, motor torque is limited to 250 Nm and motor power is limited to 50 kW. In the latter condition, the driver should be able to hold the vehicle stationary regardless of accelerator pedal position with 85 to 170 N (19 to 38 lbf) of brake pedal force, depending on the platform.

Are you seeing behavior that is in conflict with that?

Suggestions of what I should do about the fact that my car does not behave like the NHTSA investigation document?

 

[MP3Mike]

Suggestions of what I should do about the fact that my car does not behave like the NHTSA investigation document?

How far are you pressing the brake pedal?

 

[Gumball]

Just pushing the brake pedal a bit so the brake lights come on is a complete different thing then actually braking.

 

[Trilodroid]

Yeah, I wonder if there isn’t some way they could regenerate even if cold, but slough off the generated current somehow rather than recharge the battery with it. So we get consistent strong regenerative braking. .

I'm definitely for this. Consistency equates to safety and satisfaction. I would also love it if they had a sort of Tesla coil on the hood and trunk emblem that would crackle with the excess power you were sloughing off. The equivalent of ICE cars and flames out of the tailpipes.

 

[Trilodroid]

Suggestions of what I should do about the fact that my car does not behave like the NHTSA investigation document?

Definitely get Tesla involved, that sure seems like a safety hazard. I wouldn't drive it till they fixed it.

 

[tomas]

I'm definitely for this. Consistency equates to safety and satisfaction. I would also love it if they had a sort of Tesla coil on the hood and trunk emblem that would crackle with the excess power you were sloughing off. The equivalent of ICE cars and flames out of the tailpipes.

Now we're talking! It should be optional... a) run it directly into a supplemental cabin heater... heck, when regen is down, it's probably cold, right? or b) zap something ornamental as you suggest, or c) laser beam death ray. So, when someone "rolls coal" at you, just hit the brakes and take out their tires!

 

[MP3Mike]

Now we're talking! It should be optional... a) run it directly into a supplemental cabin heater... heck, when regen is down, it's probably cold, right? or b) zap something ornamental as you suggest, or c) laser beam death ray. So, when someone "rolls coal" at you, just hit the brakes and take out their tires!

Maybe you should look at how big, and expensive, a 60kW heater would be. And then you need control ability to precisely control the amount of power it uses. It wouldn't be a cheap, or easy, thing to add.

 

[tomas]

Maybe you should look at how big, and expensive, a 60kW heater would be. And then you need control ability to precisely control the amount of power it uses. It wouldn't be a cheap, or easy, thing to add.

Was I Joking???

 

[hybridbear]

How far are you pressing the brake pedal?

Far enough to activate the brake lights which per the NHTSA document should limit motor power to 50 kW.

Just pushing the brake pedal a bit so the brake lights come on is a complete different thing then actually braking.

Except that, per the NHTSA investigation there is no required amount of brake pedal pressure for the car to limit motor power to 50 kW when both pedals are pressed. The NHTSA just stipulated the amount of brake pedal pressure required to be stronger than the 50 kW of motor power.