Maverick Hybrid engine surge.

[Boltfan66]

I am curious if anyone else in this forum has had their Hybrid Maverick engine race to full throttle unexpectedly?
Last week, I allowed my son to drive my truck, and he called me to explain how the truck, shortly after starting up the engine, raced to full throttle.
I told him he must have had his foot covering the accelerator at the same time as depressing the brake. Nothing to worry about, I will check the vehicle later.
Little did I know that the same thing happened to me just a couple of days later. I had just stopped to refuel and proceeded to start the vehicle just before engaging the transmission, the engine raced up to full throttle. I was startled for a moment and shut it down by turning off the key. This has never happened before in this vehicle in the three years that I have owned it. Has anyone else experienced this or anything similar?

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[Mavster Mechanic]

How cold was it?

High idle: 1850 (instead of 1250) in the cold is normal.

Full throttle is 5600 and very abnormal (and scary - more than just startling)

Do you KNOW it was more than high idle?

 

[OleFordGuy]

Yep recall several threads describing this in the past

 

[OleFordGuy]

https://www.mavericktruckclub.com/forum/threads/potentially-dangerous-high-engine-rev.76281/

 

[Boltfan66]

How cold was it?

High idle: 1850 (instead of 1250) in the cold is normal.

Full throttle is 5600 and very abnormal (and scary - more than just startling)

Do you KNOW it was more than high idle?

The idle sounded like an engine hitting its rev limiter. I have no tach to verify RPMS but it was unsettling.

 

[skinnyboy]

Had it rev very, very high several times in "gear" after parking for about 20 mins., but never in park.

Cheers.

 

[johnDeere]

You mean like this.
This was the first time for me.
I was in drive, coming to a stop.
Lucky my foot was on the brake.

 

[OleFordGuy]

You mean like this.
This was the first time for me.
I was in drive, coming to a stop.
Lucky my foot was on the brake.

Wow that ought to rid the comments going forward that it’s normal when cold, it probably wasn’t as high rpm as you thought, etc. Soiid proof something’s not right and could be dangerous, that’s my 2 cents on the matter

 

[OleFordGuy]

Out of curiosity, how did you capture that?

 

[710-oil-614]

Wow that ought to rid the comments going forward that it’s normal when cold, it probably wasn’t as high rpm as you thought, etc. Soiid proof something’s not right and could be dangerous, that’s my 2 cents on the matter

That's a good screenshot that we've been asking folks reporting for. That does validate the spike in RPMs to upper 3000s but it surged for 1 second before backing off.

 

[skinnyboy]

You mean like this.

Cool that you captured this situation with data, and appreciate you posting it! Definitely not normal operation, and it is unsettling when it happens. Toyota hybrid never did this.

Cheers.

 

[HeyBales]

Nice capture.
I've not noticed that effect yet.
And despite not being what others may think is the redlining 5-6k RPM sound, it still sounds very loud at 3700.

Seeing 4K steady on downhills when HVB was full - sounded way louder than I'd thought 4K would sound.
I guess because normally that is noisy highway or hard acceleration level sound - so wind and tire noise going along with it. Doing 25 mph down a hill, or braking to a stop, or idling - makes that noise so much worse.

 

[Mavster Mechanic]

You mean like this.
This was the first time for me.
I was in drive, coming to a stop.
Lucky my foot was on the brake.

It does this in my 2022 anytime I am braking coming to a stop with a full HV battery.

This looks like "engine braking".

If it goes away after a full stop, I'd say it's operating as designed.

3800 is not that high and mine does it all the time.

It is also designed to do this with a very cold (sub 32°F) HV battery. Which is why it shows up more in cold weather.

 

[Mavster Mechanic]

Cool that you captured this situation with data, and appreciate you posting it! Definitely not normal operation, and it is unsettling when it happens. Toyota hybrid never did this.

Cheers.

Two Toyota Hybrids I owned did this.
(For brief engine brake when the hybrid battery was full, cold, or both.)

A Rav4 Hybrid does this.
A Venza Hybrid does this.

With better cabin sound proofing I will say it is much less noticeable in the Toyotas.

 

[johnDeere]

It does this in my 2022 anytime I am braking coming to a stop with a full HV battery.

This looks like "engine braking".

If it goes away after a full stop, I'd say it's operating as designed.

3800 is not that high and mine does it all the time.

It is also designed to do this with a very cold (sub 32°F) HV battery. Which is why it shows up more in cold weather.

Not engine braking unless the “L” is pressed and I was going 10 mph.

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