Is this normal? Engine stalled

[03_4x4Runner]

The other day I pulled onto my fairly steep driveway and I climbed about 5'-10' when I decided to stop and check to see if the mail came. I did not shift to reverse but left it in drive and started coasting back to the mailbox while riding the brake to control backwards speed. All of a sudden the engine stalled and the dashboard lite up. I picked up the mail and restarted the engine and all was fine. I guess the computers do not like the 4runner being in drive and rolling backwards. None of the other cars I have owned including my old 4th gen if I recall has ever done this. I only rolled back maybe 20'

 

[1engineer]

I always shifted to N or R. Any reason you left it in D? When I put it in the aforementioned gears I have never had it stall and die.

 

[96r50]

That is normal for an automatic transmission. By leaving it in D it is still coupled to the drivetrain and expecting forward movement. When you let it coast backwards in D it puts a load on the engine and quickly stalls it since you're not pressing the gas. Definitely not a good practice on a regular basis.

 

[wfo9]

That is normal for an automatic transmission. By leaving it in D it is still coupled to the drivetrain and expecting forward movement. When you let it coast backwards in D it puts a load on the engine and quickly stalls it since you're not pressing the gas. Definitely not a good practice on a regular basis.

I sort of doubt that is what happened, but I can't say for sure since I have never tried it. Maybe if he was rolling backwards pretty fast.

An automatic has a fluid based coupling between the transmission and the drive shaft called a tq converter. These couplings have a rated stall speed, which is the max RPM the motor can hit without the drives shaft starting to rotate (with the brakes on...) You would have to be rolling backwards pretty fast for this to create enough friction in the fluid based coupling to create a stall. Now, if the lockup (more of a clutch plate) engaged, that would cause a stall. I guess that is possible.

The center diff, may make this behave sightly different than what you are familiar with.

Overall, nothing to worry about.

 

[JSparky]

This happened to me back in high school wheeling a dodge durango. Had to reverse down a steep, muddy hill and thought I was being clever leaving it in drive and "braking" using the throttle. Truck stalled, lost power steering and brakes, and almost rolled off into a ravine. Never again. Now I'm curious, Crawl Control in reverse? Gotta try that.

 

[BlackWorksInc]

I wouldn't worry about it too much, it sounds like the vehicle didn't like rolling backwards in Drive.

 

[03_4x4Runner]

I always shifted to N or R. Any reason you left it in D? When I put it in the aforementioned gears I have never had it stall and die.

I guess I was just being lazy but did not really give it much thought. I only backed up maybe 20' at less than 5 mph. It just took me by surprise when it stalled and buzzer and lights going off all over. It freaked my wife out setting in the passenger seat.

 

[1engineer]

I guess I was just being lazy but did not really give it much thought. I only backed up maybe 20' at less than 5 mph. It just took me by surprise when it stalled and buzzer and lights going off all over. It freaked my wife out setting in the passenger seat.

Hey. Re read your last post and I believe you experienced the anti roll back feature called Hill start Assist Control or (HAC). Do me a favor: Go back to that spot and stop where you did but firmly depress the brake this time while in drive. You shouldn't roll back. Next do it again and just come to a gradual stop while gently depressing the brake. You will then hear buzzer and see lights as you start to roll back.

 

[03_4x4Runner]

Hey. Re read your last post and I believe you experienced the anti roll back feature called Hill start Assist Control or (HAC). Do me a favor: Go back to that spot and stop where you did but firmly depress the brake this time while in drive. You shouldn't roll back. Next do it again and just come to a gradual stop while gently depressing the brake. You will then hear buzzer and see lights as you start to roll back.

No, it was not that feature. I have used that feature several times on the same driveway just playing with it. The HAC feature works great. When I started backing up to get the mail the brake was not on at all. I just came to a stop with the brakes, then let go of the brake to roll backwards.

 

[1engineer]

No, it was not that feature. I have used that feature several times on the same driveway just playing with it. The HAC feature works great. When I started backing up to get the mail the brake was not on at all. I just came to a stop with the brakes, then let go of the brake to roll backwards.

That's what I mean. If you don't depress the brake firmly (read stomp) then it will roll back and make noise and lights flash. I just have never let mine roll back far enough to kill the engine. If you don't depress the brake firmly, I think the HAC tries to engage but can't. I have experienced this many times.

 

[Canon_Bob]

Seems like weird behavior to me if it's functioning as designed. Would hate to have a stall like that during a hill climb where I lost traction and was just letting it roll backward slightly for a better line. Interested in hearing more (is it just in "Drive" that this happens, or 2WD only, etc..). Just curiosity on my part, as I think I'm taller than the highest hill in FL anyway, so it will probably never happen here. Just seems like a strange behavior for a 4WD vehicle where one could be expected to climb some hills, and roll backward on occasion.

 

[mace.]

Would hate to have a stall like that during a hill climb where I lost traction and was just letting it roll backward slightly for a better line.

If you lose traction on a hill climb you shouldn't be letting it roll back in drive anyway. You should be using reverse to go back down.

 

[03_4x4Runner]

Interested in hearing more (is it just in "Drive" that this happens, or 2WD only, etc..).

I am full time 4x4 so no issue there. Shifter was in sport mode 4th gear position.

 

[Canon_Bob]

If you lose traction on a hill climb you shouldn't be letting it roll back in drive anyway. You should be using reverse to go back down.

Heck I can't imagine climbing a hill in "drive" anyway. I'm asking the question more out of curiosity than anything here. We all know "stuff happens" sometimes when your navigating a trail (failing to hit a small hill with enough momentum to get all the way up or whatever), and I'm just curious to understand the reasoning behind a "feature" that would add complication to the situation by causing a stall. That's all. If rolling backward in "Drive" could damage the vehicle, then I get it.

When I lived in Denver, it wasn't uncommon at all to roll slightly backward down an icy hill in Winter while in drive. Many times the cars in front of you spun out or stalled out on the icy hill, and you'd have to let off a bit (sometimes going slightly backward) to navigate around them. I would think a factory initiated "stall" would make that situation worse. Again, not something I've ever had problems with. I'm just curious as to the logic of causing a stall intentionally. I would hope that it's to protect the vehicle from serious damage, otherwise it doesn't make a lot of sense to me.

 

[BlackWorksInc]

HAC like DAC only activates within a narrow speed/parameter band, if it starts rolling too fast and/or those requirements are not met the system will not kick in (I rarely if ever have it kick in when I am in San Francisco and I usually end up creeping/sitting still on hills with my foot off the brake.)

I've never tried rolling a vehicle really far backwards while in drive, usually I tap it into neutral and/or reverse before then.

 

[Steamtrain]

I've had this type thing happen twice in less than 2 months driving a 2015 SR5.
It took very little speed or distance to get the warning lights and buzzers activated. Engine stalled neither times, but it was backwards less than 3 feet each time.

Rolled backward in drive at a stop light: stopped at red light, foot came off the brake, put it on the accelerator to go up hill, rolled back a bit since the first car at the light was not paying attention to the light changing to green(movement like when on a hill with a standard transmission), warning lights and buzzer come on.

 

[Jeremy556]

I've had this type thing happen twice in less than 2 months driving a 2015 SR5.
It took very little speed or distance to get the warning lights and buzzers activated. Engine stalled neither times, but it was backwards less than 3 feet each time.

Rolled backward in drive at a stop light: stopped at red light, foot came off the brake, put it on the accelerator to go up hill, rolled back a bit since the first car at the light was not paying attention to the light changing to green(movement like when on a hill with a standard transmission), warning lights and buzzer come on.

That's what it's supposed to do :ybrick:
hill start assist, or some such