Hard stop when coasting downhill to a stop. Transmission issue?

[Codyfsu1]

FWIW, this most likely is not mechanical at all. The Maverick hybrid transmission has very few moving parts - like maybe 12 total? (Seriously! It is very clever.) Very reliable for that reason. It's extremely similar to a Prius transmission, and there's a reason so many taxis are Priuses.
Probably what you're experiencing is just the software being not perfectly tuned. My guess is that one of the many sensors gives a slightly wonky response at a particular temperature/ humidity.

Honestly that is what it feels like since it only does it every once in a while and only when I am coming to a stop rolling downhill. But when it does it is pretty abrupt. My wife even said "what the hell" the other day when it did it. Just weird.

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[fordvideoguy]

@fordvideoguy

I have always wondered....

If I document a powertrain concern at 57k 58k 59k miles but the dealership says "could not replicate / could not verify" and then the "problem" gets worse and becomes apparent to them undeniably at 62k miles.... is that still a warranted repair?

Thanks for your insight.

I can't help answer that question. I would think if it was documented by the dealer then it should be but I'm in sales not service.

 

[HeyBales]

Okay so this is hard to describe but I feel like the issue is getting worse. Every once in a while when I coast to a stop the car feels like it lurches forward harder than normal and then stops. I'm guessing it is when the car switches over to electric and the brakes engage. It just seems to keep getting more and more aggressive. I hope it is not a major issue because mine is a 23 hybrid with 57k miles and the warranty is done at 60k miles for the powertrain. I drive a ton for work. Anyone else having this issue?

So this is the final moments before stop then, not early during the coast down and a bit of time/distance is left?

Can you tell if the engine is just turning off at that point, or because of coast it was already off?

During the coast was your regen braking all that was used (within the green somewhere), or hard enough the needle pegged and mech brakes already engaged a few times? (regen is still used during this time)

If the final moments only and no mech brakes to this point and no engine on (if engine running then the generator motor would be turning for gearing changes and possible recharge mode) - sounds like the issue several talked about with cheaper parts then other Ford hybrids that don't show this problem.

A short in the charging system from the regen would also cause the transaction motor to provide huge resistance - not sure how that would show in the regen gauge - perhaps peg the needle too.

 

[The Real Maverick]

I can't help answer that question. I would think if it was documented by the dealer then it should be but I'm in sales not service.

Don't you guys chat around the coffee pot / water cooler?

 

[fordvideoguy]

Don't you guys chat around the coffee pot / water cooler?

I don't have time for the water cooler talk.

 

[MetalsGeek]

This sounds like a common issue with the service brakes on hybrids. I have a '23 XLT with less than 10K miles and I often experience a mild version of what you describe. When you press the brake pedal, it does not directly affect the brake pads. It's a command to the system, which attempts to use regenerative braking as much as possible. When the vehicle slows to the point where the motor/generators can no longer make usable power, it switches over to friction braking at around 5 MPH to bring you to a stop. These two braking systems are "supposed" to provide similar deceleration for a given pedal pressure, but this calibration is clearly no easy thing to master. I would not be surprised if the friction brakes change their effectiveness with temperature, humidity, or whether they've been used recently. Wish I knew more about the details.

 

[Codyfsu1]

**update** At 59,600 miles I dropped it off at the dealership to see if they could diagnose the problem. I had my doubts because it only does it every once in a while. 4 days later and very little communication I was told they did a software update to fix the issue. $200 diagnostic fee and $100 labor. Wasn't happy about that since I feel like it is a warranty issue. Driven a few hundred miles and it seems to have fixed the issue. We will see.

 

[Tallymav]

This sounds like a common issue with the service brakes on hybrids. I have a '23 XLT with less than 10K miles and I often experience a mild version of what you describe. When you press the brake pedal, it does not directly affect the brake pads. It's a command to the system, which attempts to use regenerative braking as much as possible. When the vehicle slows to the point where the motor/generators can no longer make usable power, it switches over to friction braking at around 5 MPH to bring you to a stop. These two braking systems are "supposed" to provide similar deceleration for a given pedal pressure, but this calibration is clearly no easy thing to master. I would not be surprised if the friction brakes change their effectiveness with temperature, humidity, or whether they've been used recently. Wish I knew more about the details.

This answer seems to be consistent with my own experience and OP. My 22 hybrid with 26k miles does the same thing. At or under 5 mph there is a noticeable release of braking immediately followed by a hard stop. It's usually pretty mild barely noticeable but under certain conditions more pronounced.

I asked the dealer to recalibrate the brakes a year and a half ago when it was in for some recall work and they said that they made some adjustments and it was better. But then I had other recalls done which flashed the computer and the problem came back. I was in for even more recalls a month ago and described All this to the dealer. This time they claimed there was no adjustment possible. Typical infuriating Ford dealership service Stonewall.

For what it's worth there is a Reddit forum on the Ionic (?) electric where people describe the same problem.

It feels just like the regenerative braking is handing off to the mechanical braking and it's not a super smooth handoff.

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