Tesla Computer Freezes Throttle at 80mph.

[Job]

When you drive a Tesla you almost never touch the brakes. It's true one pedal driving. Taking your foot off the accelerator engages pretty vigorous regeneration and you come to a complete stop quite fast. You decelerate vigorously enough that brake lights are shown whenever you take your foot off the accelerator. You could stop faster by using the brakes too but you just hardly ever need to do that.

Through experience I've learned to come to a complete stop at a stop sign by letting off on the accelerator at an appropriate distance. It will even comes to a complete stop when coasting down a pretty steep hill.

Never heard of that before. At a stop, releasing the brake on a Volt or others with automatic transmissions gives the usual creeping movement almost perfectly like a gas car with an automatic. It’s done by design. Not sure about the safety of the off entirely design which means to to creep forward in traffic you have to press the go pedal.
On the policeman in the Lexus, the car had the wrong floor mats and the previous driver of the car complained about unintended acceleration when he turned it in. They didn’t do anything about it. Not the same thing as this Tesla. It also doesn’t make this case go away. I think they call this whatabout these days as people defend by saying whatabout that other one, changing the subject.

 

[RooflessVW]

So what to do? If the accelerator doesn't control the forward movement of a Tesla, seems there are only 2 possibilities: (1) stand on the brakes as hard as possible, once only and don't let up, or (2) put the shifter into neutral and steer to the side of the road (which seems like the better option).

If a Tesla is trying to maintain speed there is zero chance the hydraulic brakes will overcome the torque of the motor(s) and stop or even significantly slow the car.

I think this is true of most cars. If the brake switch didn't override cruise control I don't think I could stop my Touareg if set to 80mph.

That said, the article isn't clear. It seems that he lost functionality of the accelerator pedal (so no regen braking) but the car was still coasting?

 

[RooflessVW]

There should be some kind of safety either programmed or mechanically on the car that gives the driver manual control in emergency situations. As a example, turn on the hazard lights and you have full throttle control. Something like a deadman switch.

There would still have to be software involved. It should be a parallel system with a brain that checks both against expected parameters.

The system should then ignore the faulty channel and light a fault.

 

[PimTac]

There would still have to be software involved. It should be a parallel system with a brain that checks both against expected parameters.

The system should then ignore the faulty channel and light a fault.

However it works it should be instant. If you are traveling at 80mph with a curve coming up you don’t want to waste any time.

I think they call this whatabout these days as people defend by saying whatabout that other one, changing the subject.

I have no idea what you said.

 

[ecotourist]

If a Tesla is trying to maintain speed there is zero chance the hydraulic brakes will overcome the torque of the motor(s) and stop or even significantly slow the car.

I think this is true of most cars. If the brake switch didn't override cruise control I don't think I could stop my Touareg if set to 80mph.

That said, the article isn't clear. It seems that he lost functionality of the accelerator pedal (so no regen braking) but the car was still coasting?

He managed to stop it somehow. [In fact he seemed most concerned about getting off the road once he'd stopped it.] Either he was able to get it into neutral or the brakes overcame the engine. I'd like to know which.

If not one of those, then how?

 

[ecotourist]

Never heard of that before. At a stop, releasing the brake on a Volt or others with automatic transmissions gives the usual creeping movement almost perfectly like a gas car with an automatic. It’s done by design. Not sure about the safety of the off entirely design which means to to creep forward in traffic you have to press the go pedal.

The Tesla has a hold feature which I really like. When you stop it when it's in drive, it just sits (whether uphill, downhill, whatever). No creeping. No need to touch the brake. It's like an 'automatically on electronic parking brake'. You have to press the accelerator to release the hold and move.

I read that at one point you weren't supposed to touch the brake at all as that would override the hold feature and then it could roll. They don't do that anymore. Mine doesn't anyway.

 

[ecotourist]

He managed to stop it somehow. [In fact he seemed most concerned about getting off the road once he'd stopped it.] Either he was able to get it into neutral or the brakes overcame the engine. I'd like to know which.

If not one of those, then how?

A third possibility is that stepping on the brake kicked it out of cruise control and he simply coasted or regenerated to a stop. That's how it should work. But that seems unlikely if the controls, as described, were "frozen at 80 MPH".

 

[RooflessVW]

He managed to stop it somehow. [In fact he seemed most concerned about getting off the road once he'd stopped it.] Either he was able to get it into neutral or the brakes overcame the engine. I'd like to know which.

If not one of those, then how?

I assume that the system that controlled the motor just glitched out and he was able to stop the car with the hydraulic brakes. The article reads like he could stop the car but didn't want to right away so he didn't get hit.

 

[denwood]

If a Tesla is trying to maintain speed there is zero chance the hydraulic brakes will overcome the torque of the motor(s) and stop or even significantly slow the car.

I think this is true of most cars. If the brake switch didn't override cruise control I don't think I could stop my Touareg if set to 80mph.

That said, the article isn't clear. It seems that he lost functionality of the accelerator pedal (so no regen braking) but the car was still coasting?

If a Tesla is trying to maintain speed there is zero chance the hydraulic brakes will overcome the torque of the motor(s) and stop or even significantly slow the car.

I think this is true of most cars. If the brake switch didn't override cruise control I don't think I could stop my Touareg if set to 80mph.

That said, the article isn't clear. It seems that he lost functionality of the accelerator pedal (so no regen braking) but the car was still coasting?

Not so…with a correctly functioning brake system, overcoming a full throttle situation with brakes only is 100% doable. Pressing hard enough (like using both feet) might be necessary though. Your brakes can bleed off a lot more energy than the car’s engine can produce. With an AWD perf version though I wonder where brake fade would occur in the scenario preventing a full stop…

If you look at the video he posted, he got the model 3 stopped, and then within moments, it rebooted. Would I pull out my iPhone and start recording in his situation? Not on your life.

The LEAF has “ePedal” mode which allows you to drive with one foot. It dials in brakes as required to stop the car if/when regen rates are exceeded, or to keep the car from creeping when stopped. I use it daily

 

[Kiwi_ME]

Even though the screen said 83 mph it also appeared to be frozen. He didn't pass the truck all that quickly. But he certainly was calm about the whole situation, all credit to him.
It seemed like the charge port opened or indicated that it was open and that put the system into some kind of logical corner case. Rather than being in a closed-loop cruise control mode where it may try to fight the brakes by adding more power (if it's not aware the brake pedal was pressed) it could also have been in locked to the last used motor current setting and therefore braking was effective at overcoming the low to moderate cruising torque of the motor. He said he didn't want to slow down too much. It also seems that a designed-in watchog of some sort may have reset the system at some point.

I'm sure Tesla will be all over this and will quickly replicate and rectify the fault. Hopefully they'll explain it as well!

 

[Job]

The Tesla has a hold feature which I really like. When you stop it when it's in drive, it just sits (whether uphill, downhill, whatever). No creeping. No need to touch the brake. It's like an 'automatically on electronic parking brake'. You have to press the accelerator to release the hold and move.

I read that at one point you weren't supposed to touch the brake at all as that would override the hold feature and then it could roll. They don't do that anymore. Mine doesn't anyway.

That’s different, in a “normal car” the right foot is alway on the brake pedal in drive, on level ground, when stopped. A clutch car the left foot is operating the clutch to moderate the movement, or in neutral I guess one can sit without pressing the brake or clutch. Other cars also have a hill holder feature, which means the motor is applying force. On a level road if the foot is off the brake and the go pedal is pressed a bit too hard, I don’t know if I would like that. I think the right foot should be on the brake in drive mode when stopped on level ground for safety. The volt and others creep forward, but at a dead stop there is no power transfer, it just moves forward when the brake is released. Never having driven a Tesla I would have to judge it in reality to know more.

 

[JeffKeryk]

That’s different, in a “normal car” the left foot is alway on the brake pedal in drive, on level ground, when stoped. A clutch car the left foot is operating the clutch to moderate the movement, or in neutral I guess one can sit without pressing the brake or clutch. Other cars also have a hill holder feature, which means the motor is applying force. On a level road if the foot is off the brake and the go pedal is pressed a bit too hard, I don’t know if I would like that. I think the left foot should be on the brake in drive mode when stopped on level ground for safety. The volt and others creep forward, but at a dead stop there is no power transfer, it just moves forward when the brake is released. Never having driven a Tesla I would have to judge it in reality to know more.

Once you have experienced 1 pedal driving, hold, etc. you will be spoiled. With the entire package, and the motor responsiveness, you have excellent control of the car.

 

[ecotourist]

That’s different, in a “normal car” the left foot is alway on the brake pedal in drive, on level ground. A clutch car the left foot is operating the clutch to moderate the movement, or in neutral I guess one can sit without pressing the brake or clutch. Other cars also have a hill holder feature, which means the motor is applying force. On a level road if the foot is off the brake and the go pedal is pressed a bit too hard, I don’t know if I would like that. I think the left foot should be on the brake in drive mode when stopped on level ground for safety.

I was taught to drive using my right foot for braking an automatic car. Doing it that way leaves your left foot available for clutch work when you drive a manual transmission car.

My impression is that a hill holder applies the emergency brake, not engine power. Applying engine power would be disastrous to the clutch with a manual transmission vehicle.

I'm not a fan of those new style/electric emergency brakes. Easy to use in 'normal driving' I suppose, but you can't modulate them. They're full on or full off. Give me a hand brake lever between the seats any day. If I lost my brakes and needed emergency braking, I'd like to be able to modulate it as you can do quite easily with a hand brake. And how could you do a hand brake turn using an electric emergency brake?

Tesla one pedal driving feels very natural to me. It's a lot like driving a manual car in a lower gear. When you lift off the accelerator you get engine braking (a bit more braking than usual but you quickly get used to that). And if you want more braking you apply the brakes too.

 

[ecotourist]

I'd suggest people test drive a Tesla. Within a couple of minutes I was sold on its one pedal driving. And then there is the terrific acceleration. Finally even a base Model 3 handles really well - about as well as my (former) BMW. They're just a great car to drive.

And if you need an intellectual reason to buy one, look at a video of the "moose test" being taken with a Tesla Model 3. It just aces it.

 

[Job]

I was taught to drive using my right foot for braking an automatic car. Doing it that way leaves your left foot available for clutch work when you drive a manual transmission car.

My impression is that a hill holder applies the emergency brake, not engine power. Applying engine power would be disastrous to the clutch with a manual transmission vehicle.

I'm not a fan of those new style/electric emergency brakes. Easy to use in 'normal driving' I suppose, but you can't modulate them. They're full on or full off. Give me a hand brake lever between the seats any day. If I lost my brakes and needed emergency braking, I'd like to be able to modulate it as you can do quite easily with a hand brake. And how could you do a hand brake turn using an electric emergency brake?

Tesla one pedal driving feels very natural to me. It's a lot like driving a manual car in a lower gear. When you lift off the accelerator you get engine braking (a bit more braking than usual but you quickly get used to that). And if you want more braking you apply the brakes too.

I changed it to right pedal soon after. Right pedal on brake gives sensitivity to the forward motion. Release it slightly the car inches forward intuitively. Car ahead moves up then stops fast? The right foot is on the brake ready to stop. How does the one pedal driving cope with that? The right foot has to take foot off gas and move to brake. What if you aren’t being so sensitive with the gas and jump it forward? The foot is not on the brake.
Manuals work great as hill holders, but you gotta be practiced with it. Automatic too, you can use those two feet.

 

[ecotourist]

I changed it to right pedal soon after. Right pedal on brake gives sensitivity to the forward motion. Release it slightly the car inches forward intuitively. Car ahead moves up then stops fast? The right foot is on the brake ready to stop. How does the one pedal driving cope with that? The right foot has to take foot off gas and move to brake. What if you aren’t being so sensitive with the gas and jump it forward? The foot is not on the brake.
Manuals work great as hill holders, but you gotta be practiced with it. Automatic too, you can use those two feet.

When you're coming to a stop using only regen, it's like you're in a low gear with a manual transmission car and you've taken your foot off the accelerator, or you're stepping on the brakes but not too hard. If you have to stop faster you step on the brake. It's all quite intuitive.

When it's on hold it doesn't move. If you touch the accelerator the hold releases and it will ease forward. And when you step on the accelerator, it goes like ...

You just have to "try it". You'll find it works quite well.

 

[denwood]

When you're coming to a stop using only regen, it's like you're in a low gear with a manual transmission car and you've taken your foot off the accelerator, or you're stepping on the brakes but not too hard. If you have to stop faster you step on the brake. It's all quite intuitive.

When it's on hold it doesn't move. If you touch the accelerator the hold releases and it will ease forward. And when you step on the accelerator, it goes like ...

You just have to "try it". You'll find it works quite well.

Yep…once you try it, you’ll find that the dance from gas to brake in stop and go traffic feels very clunky in an ICE car. The only “issue” is going from cruise to ePedal as the car will decelerate more than you would expect (compared to ICE) if you don’t touch the accelerator. Just takes a slightly different technique.

The ePedal also works surprisingly well in ice/snow where aggressive regen on one axle might otherwise cause some scary handling. The stability management works in tandem with the brake controller and regen electronics to ensure the vehicle brakes as expected, while dialing in max regen when possible. It’s pretty “idiot proof” in snow.

 

[Jetronic]

Did the computer reboot take very long? Did it reboot spontaneously?

it took him a minute or 2 I seem to remember, but he was walking between vehicles so less than that. Still, glove box... and mirror.... shouldn't impact any computers to that extend

 

[Jetronic]

Never heard of that before. At a stop, releasing the brake on a Volt or others with automatic transmissions gives the usual creeping movement almost perfectly like a gas car with an automatic. It’s done by design. Not sure about the safety of the off entirely design which means to to creep forward in traffic you have to press the go pedal.
On the policeman in the Lexus, the car had the wrong floor mats and the previous driver of the car complained about unintended acceleration when he turned it in. They didn’t do anything about it. Not the same thing as this Tesla. It also doesn’t make this case go away. I think they call this whatabout these days as people defend by saying whatabout that other one, changing the subject.

Our hybrid busses are the same, you only need to use the brake from 3 mph to 0 if the regenerative braking is potent enough.

 

[George Bynum]

Once you have experienced 1 pedal driving, hold, etc. you will be spoiled. With the entire package, and the motor responsiveness, you have excellent control of the car.

Sounds like a hydrostatic drive, all of those things, albeit far less energy efficient.