Engine stalls rolling backward

My 2018 Tacoma stalls when in drive rolling back from a stop on hills. I just got it back from the dealer who checked it and said they couldn't find any issues. No codes. Is this a known issue? The oil pressure warning comes in after stall, as well as the high temp warning and trans temp warning. Then it takes many cranks to restart.

 

I've had this exact thing happen to me with my 2018 and I think its a known issue.

 

Why are you rolling backwards in drive?

 

Maybe I am missing something... Your truck stalled while rolling backward while transmission was in drive?
Pretty much every vehicle I have ever had will do this if you roll far enough.
I learned to A) Put it in Reverse or B) to give it the gas to keep from rolling back.

What are your expectations?

 

I like to use the parking brake lever.

 

Ok I’ll bite. Have to know. Why? Why would you ever do this?

 

It could be that whatever you're doing prior to the stall event is indeed heating up the transmission. The oil pressure light will come on after engine speed drops lower than about 300 rpm no matter what, so that's normal. Not the stall, but the lopw light. If you're rolling back when in drive, you're generating a ton of heat from torque converter slip. The engine is spinning one direction and the trans input shaft is spinning the other direction. The torque converter is a fluid coupling and it must be the mediator to allow that to happen, and it really doesn't like slipping. If you go fast enough backwards while in drive, the sheer negative torque coming from the wheels will kill the engine, but you'd have to be going pretty fast, north of 10 mph. If you roll back and forth up the same stretch of hill for minutes at a time, that could put enough heat into the transmission to cause the high trans temp warning, and the truck will stall to try to save itself from a clueless driver. also explains the refusal to restart immediately. I seriously doubt that's what's happening though. The trans fluid also runs through the radiator, so if it heats up, it can theoretically heat up the engine coolant too, maybe causing that other warning, but this would take a very long time, but not inconceivable if low forward and reverse speeds are used for prolonged periods. On occasion you will see dummies towing an automatic vehicle with the wheels on the ground and the driveshaft not removed, and when they go to start it, it won't because the head gasket blew while it was being towed. The internal friction of the transmission, even in neutral, heats up the ATF, which heats up the radiator and heats up the coolant, heating up the block, and the head gasket fails.

Whatever is going on, it's not normal.

 

The truck doesn't hold the hill. It rolls back when I let off the brake. So it's it supposed to hold the hill, or is it supposed to roll back when I let off the brake and move to the throttle? I've been driving for 40 years and never had a problem. I used to drive tanker trucks too, so I'm not a novice driver.

 

My Tacoma is the first AT I have had in 35 years, so I drive it like an MT on steep hills (minus a clutch pedal). If you are used to driving a MT, it should be no problem moving your right foot from the brake to the accelerator pedal with very little roll back.

 

Not being snarky here, but is the engine actually dying or is it the ABS system kicking in?
Mine will roll back some before the ABS/traction control whatever kicks in, and when it does it will limit some forward progress as it attempts to keep the truck from rolling back anymore.

 

I use my left foot to brake sometimes. Like holding a hill with my left foot while I give it gas with my right.

Also works great to get instant hard launches when someone pulls into the right lane (which ends in 50 yards) at a stop light to pass me lol

 

My Tacoma has never rolled back on a hill when in gear. When I let my foot off the brake on this hill, it stays perfectly still.

 

Offroads have a different brake system which has a much worse hill hold feature than the non-offroad/pro models.

 

That's good to know. I wasn't aware there was a hill hold feature at all.

 

Tacoma and hard launch go together about as well as beer and cucumber juice.

 

It's odd for an automatic to roll backwards on a hill and stall. How far is it rolling backwards? If you are on level ground, put it in D, and let your foot off the brake, what does it do?

I would not worry about the warning lights. It’s normal for them to light lip whenever the engine stalls and the ignition is still on. There’s no oil pressure when the engine is not running, but it doesn’t have any consequence.

It’s also normal for an engine to be slightly harder to start after stalling. I’ve never known for sure why. It’s possible the spark plugs get covered with fuel or soot right before the engine stalls.

 

I'm super intrigued by this thread. What amount of time are you rolling backwards, or what distance? How steep of a hill are we talking?

As for the offroads hill assist, I don't understand it at all. Mine will definitely allow you roll back an uncomfortable amount of distance when switching from brake to gas on a hill. I've experienced the nasty kicking/grinding braking feature thats supposed to stop you from rolling back, but it just continues to roll back. I assume if you let it go far enough, it'd catch you, but its gotta be a stupidly uncomfortable amount of distance before that takes place I guess, because I've cringed every time. To avoid it, I give her the beans while holding/releasing the brake pedal. From boat ramps to mcdonalds drive thru, if its more than about a 15 degree grade, shes getting double footed lol.

 

Yup, it’s normal. The main downside to the OR hill assist system is that it does not let you roll back in drive when you want to- I hate this when wheeling-

As for the why’s one would do this?

On my 1st gen without it, a useful maneuver was to roll back a bit when going up a steep slope where you get stopped by a ledge, a rock, or even a spot of ice and you want to back up a bit to get a faster run to it. Well, try it with an OR and the truck doesn’t let you do it in drive, instead you have to put it in Reverse which is stupid and unsafe, especially when going up a steep hill because then all you have to stop you are your brakes!

 

My hill assist catches within 5 feet or less, but even that is not short enough for some of the stupid tailgaters who stop right behind me on a hill, especially when towing a camper trailer!

 

I'll bite. I've stalled mine once rolling in the wrong direction. Backing my trailer into my driveway, thought I would let it roll the wrong way for 10 feet so I could readjust my approach. Truck shut down and called me a dumbass, rightfully so.