2022 T8 ER - B drive mode braking issue

david.givens.nc · May 1, 2023

I searched through the community best I could to see if there was information related to this topic and didn't find anything. We were going to call the dealer but I thought I would throw this out here first for some feedback. We have a late model 22 XC60 ER T8 w/AAOS and when doing local driving we drive mostly in Pure mode with one pedal driving. A while back we ran across an issue while driving when we pulled back from the pedal and when the regen braking should immediately start to kick in, the car would remain at speed until you actually hit the brake. It's not like it was coasting, it remained at speed like the pedal was pushed. When this first happened, we rebooted the car and everything seemed fine. Over the last couple of weeks it started to occur again and actually happened twice today, requiring 2 reboots of the car.

I was wondering if anyone else has experienced this. As a side note we have been driving pretty trouble free for a while. We will be approaching the one year anniversary of buying the car with just under 12,000 miles. We are on the latest software version of 2.7 I believe.

Thanks for any comments or thoughts. Dave

AvocadoFarm · May 1, 2023

That's a little scary...Are you certain Pilot Assist was not engaged accidentally or otherwise?

david.givens.nc · May 1, 2023

We did check that and Pilot Assist was not engaged. In fact when this happened today it was right after starting the car in the garage at home. We backed out into the turnaround, put the car in B mode started down the driveway at a slow speed and went to pull off the accelerator to stop at the end of the driveway and the car just kept going until we hit the brake. Needless to say we'll stop using the one pedal driving option until we can get this checked. It also never happened prior to Version 2.7 so I'm not sure if that anything to do with it? Not saying it did but would not want to rule it out. Another comment, once we reboot the car it seems to drive without issues for a while but it comes back. So being a sporadic issue will probably be hard to diagnose. Honestly we thought we were doing something stupid but we've had the car now for a while and using the one pedal method just seems natural to us at this point.

AvocadoFarm · May 1, 2023

Interesting. Please post the resolution if when (if?) you find it.

Walkabout · May 1, 2023

First report I've seen of anything like this.

I think you'll have a problem with the dealer though. If they fail to replicate the problem, and do not find an error code, they will tell you that the vehicle is operating as it should.

Pioneer4x4 · May 1, 2023

A reminder, car will not decel/regen brake in B with a full battery. Probably not what you experienced, but keep that in mind.

david.givens.nc · May 1, 2023

That could have been what happened today. I'll report back to everyone, if/when we find something out.

Walkabout · May 2, 2023

I thought the buffer space was some kind of protective feature.

I don't this is what is happening for the op in any case. Go around the block in pure and you've already made battery room.

How'sVolvo · May 2, 2023

Get it checked out because something is wrong. I've had my 2022 late xc60 recharge er for 10 months and charge it to full battery every day and that has never happened to me. Knock on wood.

DFrantz · May 3, 2023

Well yeah if you're using hold... I mean for normal driving, you're going to use more than you make. But okay, if you live at the top of a hill you'd need a way to burn out those extra watts.

Pioneer4x4 · May 3, 2023

Yep, it all comes down to WHEN you want to burn those electrons, ideally, at least 25%-35% of them ASAP so you can regen more efficiently/effectively, boosting your overall economy.

cometguy · May 3, 2023

Maybe I missed something, but I didn't see any mention of speed while in "B" mode by the OP. My car's software works such that at highway speeds, the slowing down in one-pedal mode is very gradual, and then around 40-45 mph the regen braking becomes much more pronounced. In my car, this blend from gradual one-pedal braking at high speeds to more aggressive one-pedal braking below 40 mph is actually quite excellent. This happens regardless of whether in "Hybrid" mode (ICE on or not) or "Pure" mode (ICE off)... I rarely drive in Power or AWD mode, so don't know if things are mapped differently there...

Walkabout · May 3, 2023

The OP did say it was local driving and that lifting his foot off the pedal had no effect on speed.

Walkabout · May 22, 2023

It doesn't work like this for me either. I've never had B not brake when I took my foot off the pedal - under any circumstances.

2022 T8 ER - B drive mode braking issue

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