[DadWagon]

Anyone else lose power when exiting a steep driveway or ramp? It has happened 4x in nearly 10k miles on our 2021 XSE.

All times while exiting a business or driveway with a steep exit trying to accelerate into traffic and I have zero power for a few seconds. Almost as if the safety sense thinks the ground is an object.

I’m bringing it in just to document it as it’s a huge issue sitting dead in the water when trying to merge into traffic

 

[Vanfam12345]

It probably detects the oncoming traffic and stops power in an attempt to prevent you from driving into it.

 

[Sienna9816]

I had felt something like this a couple of times. I was turning sharp and fast from stops. I suspect it was roll-over protection kicking it. It wasn't long, may be a quarter second? But it felt long.

 

[Broncofan]

I have had several hybrids (Sienna has not yet arrived), 2 Toyotas, 2 Hondas, and all of them would charge the battery when going downhill. I dont think you have a need for power when coasting downhill, mostly. Key word "when going downhill". Your car is slowing down on exits, charging the battery. My opinion is dont worry about it, the hybrid system is great, but not perfect.

 

[exmachina08]

Not sure if the Sienna does it, but the Gen 2 & 3 Prius had a transaxle protection on loss of traction. It would cut power when you slipped even a little bit to keep the electric motors from applying too much torque. Are you stomping on the gas when this happens? Also FWD or AWD?

 

[DadWagon]

It probably detects the oncoming traffic and stops power in an attempt to prevent you from driving into it.

There is no traffic in front of me when I merge out of a business from a stop.

 

[DadWagon]

Not sure if the Sienna does it, but the Gen 2 & 3 Prius had a transaxle protection on loss of traction. It would cut power when you slipped even a little bit to keep the electric motors from applying too much torque. Are you stomping on the gas when this happens? Also FWD or AWD?

I’ve driven a Prius for a few years and never experienced it.

How it always happens is I let my foot off the brake as I prepare to merge and when I hit the gas there’s no power for 2-3 seconds when my foot is flat on the gas.

I usually don’t accelerate downhill as it has no front clearance. I wait until the vehicle is relatively flat. I have a AWD

 

[DadWagon]

I have had several hybrids (Sienna has not yet arrived), 2 Toyotas, 2 Hondas, and all of them would charge the battery when going downhill. I dont think you have a need for power when coasting downhill, mostly. Key word "when going downhill". Your car is slowing down on exits, charging the battery. My opinion is dont worry about it, the hybrid system is great, but not perfect.

sorry for any confusion. The condition I’m describing is not coasting downhill doing regen. It’s from a stop

Imagine you are exiting a business that isa few feet higher than street level. From a complete stop, and your van is pointed downhill or down the ramp, as you prepare to merge by releasing your brake to get over the line and you hit the gas there is zero power. It’s like you’re coasting in Neutral for 2-3 seconds. Then power slowly comes on. Similar to starting a manual transmission vehicle in 2nd gear.

 

[DadWagon]

These are the actual exits it happened. Not that steep from GoogleStreetView camera I guess 😀 but it is downhill.

 

[Vanfam12345]

There is no traffic in front of me when I merge out of a business from a stop.

The van may disagree. The explanation provided explains the behavior even if it’s a false positive when detecting oncoming vehicles.

Maybe it’s not that. None of us can know without experiencing it ourselves. Just offering ideas since you asked for ideas.

 

[Sienna9816]

From my experience, if TSS kicks in, it usually has alerts or messages on the MID.

For my two somewhat similar experiences, I don't recall seeing any alerts.

 

[pamhar]

Only had happen once and not even sure it was same as being discussed.

Was in PA and just stopped for gas. The station was lower then the road around it and the road was a bit lower then where the edge of the gas station meets the road. So like going uphill and then a bit downhill.

Was turning left onto road when lost power for a split second. Not sure if it was having the rear tires lower relative to the front tires plus turning. No wheel spin and no alerts on MID.

 

[DadWagon]

From my experience, if TSS kicks in, it usually has alerts or messages on the MID.

For my two somewhat similar experiences, I don't recall seeing any alerts.

Same, I have not heard any alerts, sudden stopping, or dash flashing STOP! as I have seen when trying to pull closer into a parking spot where there’s a planter, etc.

Just complete loss of power

 

[DadWagon]

Only had happen once and not even sure it was same as being discussed.

Was in PA and just stopped for gas. The station was lower then the road around it and the road was a bit lower then where the edge of the gas station meets the road. So like going uphill and then a bit downhill.

Was turning left onto road when lost power for a split second. Not sure if it was having the rear tires lower relative to the front tires plus turning. No wheel spin and no alerts on MID.

Do you have an AWD by chance?

It happens sometimes during a reverse too when backing out of my driveway, switch to drive, and nothing until the engine kicks in. Happened twice this Summer as I remember having AC on full blast and thought it could be an issue.

 

[pamhar]

Do you have an AWD by chance?

It happens sometimes during a reverse too when backing out of my driveway, switch to drive, and nothing until the engine kicks in. Happened twice this Summer as I remember having AC on full blast and thought it could be an issue.

No, FWD.

Has only happened once thankfully.

It was in summer so wonder if having AC on [especially at high] is a factor?? Can't remember what we had it on but possibly AUTO so could have been running high.

 

[exmachina08]

And it's not just the typical hybrid spool up lag? Are you in eco or normal/sport mode? That is strange, haven't experienced it yet but we don't have to many entrances/exits that steep in my area.