Rollaway while outside of the car

[thenicos]

Hi Everyone,

I just had an incident this morning that luckily ended in no harm to anyone but wanted some feedback on if anyone else had this issue and the best way to contact Tesla.

I was leaving my garage this morning and was driving up my driveway. I drove up about 15 feet, put the car in park, and got out of the car to help put my son's booster seat in the car. I got out, closed my door, walked around to the rear passenger door and opened the door and installed the seat.

As my son was getting in the car, I walked back to the drivers side, opened the door and as soon as the door unlatched, the car started rolling backwards. I was luckily quick enough to slam on the brakes right away before my son got injured, and also luckily I had the foresight to leave my garage door open in case I got stuck on the snowy incline and needed to power up the driveway.

I'm really confused as to how this could happen. I'd love this to be human error so I could re-assure my son and wife it won't happen again but even if I forgot to put the car in park (which is possible), my understanding is that as soon as I opened the door and got out, it should be in park.

Any thoughts? I found a similar post from 2 years ago but the situation was different as the person was in the car when the rollaway happened.

Is there anyway to get Tesla to look at this and have them review the incident?

I have a video from my driveway cam but it cuts off just as the car starts rolling away.

I appreciate the feedback.

Thanks,
Jason

 

[jjrandorin]

and also luckily I had the foresight to leave my garage door open in case I got stuck on the snowy incline

How do you know that this is not the car sliding down the "snowy incline" of the driveway?

but even if I forgot to put the car in park (which is possible), my understanding is that as soon as I opened the door and got out, it should be in park.

This is true, as long as the seat sensor is working. You can test this yourself by (on a flat surface) leaving the car in drive, opening the door and getting out.

 

[stopcrazypp]

Hi Everyone,

I just had an incident this morning that luckily ended in no harm to anyone but wanted some feedback on if anyone else had this issue and the best way to contact Tesla.

I was leaving my garage this morning and was driving up my driveway. I drove up about 15 feet, put the car in park, and got out of the car to help put my son's booster seat in the car. I got out, closed my door, walked around to the rear passenger door and opened the door and installed the seat.

As my son was getting in the car, I walked back to the drivers side, opened the door and as soon as the door unlatched, the car started rolling backwards. I was luckily quick enough to slam on the brakes right away before my son got injured, and also luckily I had the foresight to leave my garage door open in case I got stuck on the snowy incline and needed to power up the driveway.

I'm really confused as to how this could happen. I'd love this to be human error so I could re-assure my son and wife it won't happen again but even if I forgot to put the car in park (which is possible), my understanding is that as soon as I opened the door and got out, it should be in park.

Here are the conditions for that mode to activate:
Model 3 automatically shifts into Park whenever you connect a charge cable or if two or more of the following conditions are met simultaneously while traveling slower than approximately 1.5 mph (2 km/h):

• The driver's seat belt is unbuckled.
• The occupancy sensor in the driver's seat does not detect an occupant.
• The driver's door is opened.

Model 3 Owner's Manual | Tesla

Understand how to shift gears and the prerequisites for each gear.

www.tesla.com

You can check if those sensors are working or not. The occupancy sensor is the one that most commonly fails.

Ideally you should make a habit of using the park button and not relying on that feature.

Any thoughts? I found a similar post from 2 years ago but the situation was different as the person was in the car when the rollaway happened.

Is there anyway to get Tesla to look at this and have them review the incident?

I have a video from my driveway cam but it cuts off just as the car starts rolling away.

I appreciate the feedback.

Thanks,
Jason

Have you eliminated the possibility of the car sliding instead of rolling? Is there a possibility of the brake calipers being iced over?

 

[XPsionic]

I have a video from my driveway cam but it cuts off just as the car starts rolling away.

Check/post it anyway. I wouldn't be surprised if your video shows the rear wheels locked and sliding on snow, and the front wheels are rotating as the car starts to "roll" away.

The parking brakes only lock up the rear wheels.

 

[hey kupo]

How do you know that this is not the car sliding down the "snowy incline" of the driveway?

Check/post it anyway. I wouldn't be surprised if your video shows the rear wheels locked and sliding on snow, and the front wheels are rotating as the car starts to "roll" away.

The parking brakes only lock up the rear wheels.

Kind of doesn't matter. OP got in the car and hit the brakes which stopped the roll/slide. Still indicates to me that the parked state may not be sufficient if it is necessary for the brake pedal to be depressed in certain conditions.

 

[E90alex]

Kind of doesn't matter. OP got in the car and hit the brakes which stopped the roll/slide. Still indicates to me that the parked state may not be sufficient if it is necessary for the brake pedal to be depressed in certain conditions.

The 3/Y is essentially a RWD vehicle with AWD on demand. So while parked it’s like any other RWD vehicle where only the rear wheels are preventing the car from moving. Getting in and pressing the brake pedal adds the front wheels in to help stop the car.

So in his case if the rear wheels were on ice and were sliding, pressing the brake pedal stopped the car cause the front wheels had enough traction to stop it.

 

[stopcrazypp]

The 3/Y is essentially a RWD vehicle with AWD on demand. So while parked it’s like any other RWD vehicle where only the rear wheels are preventing the car from moving. Getting in and pressing the brake pedal adds the front wheels in to help stop the car.

So in his case if the rear wheels were on ice and were sliding, pressing the brake pedal stopped the car cause the front wheels had enough traction to stop it.

Yep, beat me to it. Pressing the brake pedal would activate the front brake, which may have been enough traction.

The same difference is also there when using Hold mode vs just the parking brakes.

There's a warning right in the manual that this situation can happen:
"Warning
In snowy or icy conditions the rear wheels may not have sufficient traction to prevent Model 3 from sliding down a slope, particularly if not using winter tires. Avoid parking on hills in snowy or icy conditions. You are always responsible for parking safely.
Warning
Your Model 3 may display an alert if the road is too steep to safely park on, or if the parking brakes are not properly engaged. These alerts are for guidance purposes only and are not a substitute for the driver’s judgment of safe parking conditions, including specific road or weather conditions. Do not depend on these alerts to determine whether or not it is safe to park at any location. You are always responsible for parking safely."

Model 3 Owner's Manual | Tesla

Understand your vehicle's braking system and stopping features.

www.tesla.com

 

[thenicos]

Hi Everyone,

Thank you for the detailed responses. It makes me feel a little more confident that my car isn't trying to kill me

A few comments

• I have a 2023 AWD with Winter tires
• I always hit Park so i'm pretty sure I did hit it but i can't be 100% confident
• I agree its most likely the car was sliding but here are a few additional comments
  • I don't recall any warnings on the car with respect to slippery but it's possible I missed it
  • My driveway is not that steep nor was it very icy .
    • I've never had issues with any other cars ever sliding down the drive way in my many years at this house but there's always a first time for everything
  • The timing was literally the second I opened the car door, it started rolling which makes me suspicious

What i'm thinking is that perhaps as my son was getting the car it added a little weight and motion in the back and triggered the car to slide.

I've uploaded a video but unfortunately the video cuts off literally just as the car starts to roll but if you slow it down you can see it start to move as I open the door.

For now I'll make some adjustments to my winter parking to compensate and try and do some testing this weekend to make sure my occupancy and seat sensors are working well (never seen any issues so i'm pretty sure they are).

Last question - is there an easy way to contact Tesla to see if they see anything from their end (in terms of sliding alerts or anything else)? Is it just a service request? The reason I ask is it seems like overkill to schedule a service appointment at the Tesla dealership just to get them to remotely check my car.

Again, I really appreciate the responses.

 

[PianoAl]

Wow, interesting.

Yes, slowing it down you can see it move. Is the driveway really steep enough that you think it's sliding? Doesn't look like it from the video.

Can you think back and recall whether the car felt like it was rolling or sliding (despite the adrenaline rush)? When you slammed on the brake, was there any sliding?

• The timing was literally the second I opened the car door, it started rolling which makes me suspicious

I would discount that. Split-second coincidences happen, and humans are predisposed to infer causality.

is there an easy way to contact Tesla to see if they see anything from their end (in terms of sliding alerts or anything else)? Is it just a service request? The reason I ask is it seems like overkill to schedule a service appointment at the Tesla dealership just to get them to remotely check my car.

That's the way I've used to get Tesla to look at things. You can always cancel the appointment. In setting up the appointment, it gives you the opportunity to send video. It's great that the video got at least the start of the movement.

One trick: Don't make the appointment for a date further in the future, thinking that will give them more time to evaluate the problem. I've found that they don't do anything until just before the appointment date.

 

[Xenoilphobe]

Wonder how hard a software lift it would be to add the front brakes to the braking brake system?

 

[E90alex]

Wonder how hard a software lift it would be to add the front brakes to the braking brake system?

There is no way to make the front brakes act as a parking brake without the car being on.

 

[stopcrazypp]

Wonder how hard a software lift it would be to add the front brakes to the braking brake system?

The rear parking brakes are screw drive electric motors which actuate the rear calipers and can hold that position without power. That's why they can actuate even without the brake pedal moving.

The front brakes are instead only actuated by the hydraulic system and they are actuated electronically by the electric brake booster, which is why the brake pedal moves when "Hold" is used. As others mentioned, it would require the car to be on to work (which I suppose those that use Sentry mode already have the car on) and who knows how much more additional power to hold the brake in that position.

It's probably not worth it, given such incidents tend to be extremely rare and especially given there are going to be situations where having the front brakes wouldn't necessarily help either (car may still slide).

 

[thenicos]

Wow, interesting.

Yes, slowing it down you can see it move. Is the driveway really steep enough that you think it's sliding? Doesn't look like it from the video.

Can you think back and recall whether the car felt like it was rolling or sliding (despite the adrenaline rush)? When you slammed on the brake, was there any sliding?

It really felt like it was rolling and not sliding but adrenaline plays tricks on the mind and our memory.

Our driveway is steep at the top but not at the bottom where the car was parked (just outside garage door). I do have "HOLD" mode enabled on the car as well.

That's the way I've used to get Tesla to look at things. You can always cancel the appointment. In setting up the appointment, it gives you the opportunity to send video. It's great that the video got at least the start of the movement.

One trick: Don't make the appointment for a date further in the future, thinking that will give them more time to evaluate the problem. I've found that they don't do anything until just before the appointment date.

This is great advice. Thank you!

 

[thenicos]

Hi Everyone,

My final update - I was able to get in touch with Tesla and they confirmed that the wheels never turned during the incident so it seems to confirm the sliding down the driveway theory.

I really appreciate everyone taking time to discuss this. Will be more careful in the winter to ensure I don't end up in a similar situation again.

 

[PianoAl]

Hi Everyone,

My final update - I was able to get in touch with Tesla and they confirmed that the wheels never turned during the incident so it seems to confirm the sliding down the driveway theory.

I really appreciate everyone taking time to discuss this. Will be more careful in the winter to ensure I don't end up in a similar situation again.

That's great news, actually. Now you don't need to worry that the car is broken or is going to do a dangerous thing in the future.

It's still a little surprising, since if the wheels were locked, slamming on the brakes wouldn't have any effect, but the car simply could have stopped sliding at that point by coincidence.

 

[thenicos]

That's great news, actually. Now you don't need to worry that the car is broken or is going to do a dangerous thing in the future.

It's still a little surprising, since if the wheels were locked, slamming on the brakes wouldn't have any effect, but the car simply could have stopped sliding at that point by coincidence.

This is a good point that I didn't think about.... Slamming on the breaks definitely did stop the car as it was a sudden jerk. I'm going to follow-up with them with this question.

Will have to continue to monitor

 

[jjrandorin]

This is a good point that I didn't think about.... Slamming on the breaks definitely did stop the car as it was a sudden jerk. I'm going to follow-up with them with this question.

Will have to continue to monitor

It's still a little surprising, since if the wheels were locked, slamming on the brakes wouldn't have any effect

How this could be was already addressed by a couple responders in this thread:

So in his case if the rear wheels were on ice and were sliding, pressing the brake pedal stopped the car cause the front wheels had enough traction to stop it.

Yep, beat me to it. Pressing the brake pedal would activate the front brake, which may have been enough traction.

 

[Darmie]

Hi Everyone,

My final update - I was able to get in touch with Tesla and they confirmed that the wheels never turned during the incident so it seems to confirm the sliding down the driveway theory.

I really appreciate everyone taking time to discuss this. Will be more careful in the winter to ensure I don't end up in a similar situation again.

Great job. interesting that Tesla has the data on the turning or lack there of the rear wheels turning. If the rear wheels were sliding and applying the brakes did in fact cause friction on the front of the vehicle to stop the momentum then there may had been your answer. That's good news. What I will say though is, this is not just an issue with only a Tesla. The parking brake on all vehicles only are applied to the rear brakes of the car. There may be some exceptions to this and it may be with an all wheel drive in park or an all wheel drive with other electrics vehicles where they use a paddle in the gearing to set park. I'm sure it was a scary feeling but good on you to keep calm enough to jump in and apply the brakes.

 

[jjrandorin]

Re reading what my responses in this thread are, they do appear a bit "dry" and "dispassionate". I didnt intend them that way. In my day job I troubleshoot IT systems for a living, so when I am troubleshooting a problem, my mind works in a certain way, with trying to eliminate variables, trying to ask questions to get to root cause, etc.

Looking at the video, that must have been extremely scary, with the OPs child getting in the car and them opening the drivers door and the car starting to move.

Kudos to the OP for the quick thinking of jumping in the car and pressing the brakes, and I do want to acknowledge how scary that must have been, I am definitely NOT trying to make light of that at all.

Where I live, It doesnt snow so I dont have to deal with something like that, but if I did, and that happened to me, I would be doing everything I could to not have something like that even have the possibility of happening again (probably clearing out the garage so I could park in there instead of on the driveway slope, or even parking on the street instead of the driveway if I could and I thought it was going to snow)

Anyway, I just wanted to acknowledge how scary that must have been, and the somewhat "dry" responses I made in this thread. They dont look rude or anything to me, but they (my responses) definitely read somewhat dispassionate, and I wanted to acknowledge the situation.

 

[Dan D.]

Hi Everyone,

My final update - I was able to get in touch with Tesla and they confirmed that the wheels never turned during the incident so it seems to confirm the sliding down the driveway theory.

I really appreciate everyone taking time to discuss this. Will be more careful in the winter to ensure I don't end up in a similar situation again.

So was it the yank on the car door that finally unsettled the car enough to slide?

If you frame-by-frame the video and look at one spot, say the black line formed by the panel gap at lower left. In every frame the black line is noticeably another pixel down the driveway. Sure, a little bit when you get in at 3 seconds and your weight is in the car, but after you get out of the car at 6 seconds and walk around to the driver's side the black line is still slowly moving down the driveway. Then quite a bit more when your son gets in. All told the car moved backwards maybe just an inch, but it was continuous when load was going in the car and coming out. I guess it was just on the verge of sliding, until it did.