Well, well, well...
Before I explain what has happened to me today, first a bit of background that I think will help frame this conversation and dispel a few 'Not used to EVs' myths in this and related threads.
So, I have been driving P2 for 11 months over the last 18 month period (there was a break early last year between my company leased P2 being returned and my privately purchased P2 being delivered during which I went back to my Ioniq BEV). In total, I have driven EVs exclusively for the last 5ish years other than the week my P2 was in the shop and I got a petrol XC40 as a courtesy car, and that is the only week in the past seven months where I have not been driving my P2 hundreds of miles a week. I am very well versed in how OPD and the like work, and my settings have not changed since about the fourth day of getting a P2: OPD Standard / Creep off. I drive almost exclusively with the go pedal, and only use the brake pedal to put the car in gear or if I need more braking force than standard OPD gives (very, very rarely). I don't routinely press the brake to engage Hold, I just let OPD bring the car to a stop and generally keep the go pedal not the brake pedal covered, ready for setting back off. The only thing I have changed recently is that I now also have the auto limiter turned on as I noticed the road sign recognition seems to have improved substantially. My car is running 3.1.9 and has been since July.
Today, I have had my first experience of the phantom acceleration. I took a trip to the city which for me consists of about 40 miles on the motorway followed by 5-10 miles of stop-go city centre traffic. On the motorway I was using PA set to 70mph but the last 10 miles of that even was congested so averaging about 20 with a lot of stop and go (still with PA engaged). Conditions were cool (about 7C) and wet (persistent drizzle), so fairly typical of this time of year.
When I exited the motorway I disengaged PA by pressing the centre button on the left of the steering wheel (but as you know, once it is activated, you can't actually cancel it without the car being put into Park or reverse.- it stays 'on' but 'inactive' (grey symbols on the dash)). I was definitely not driving with ACC/PA at this point though, the car was responding entirely to my inputs on the accelerator, back to what I would call standard OPD mode with all the assist-related icons greyed out...
A few miles off the motorway and in consistent stop-start traffic doing no more than 10-20mph (and even then only for very short bursts), I came to a gentle stop from about 10 mph behind another car at some traffic lights - completely flat road, no perceivable gradient. As usual, I did not touch the brake during this procedure letting OPD bring me to a stop, but thankfully I left a good 1.5-2 car lengths to the car in front (lots of cars trying to change lanes and I like to try and be a thoughtful driver and give space for such). There were no 'brake' related lights on the dash (no (P) or (H)) as I had not touched the brake pedal.
About 10-20 seconds after coming to a stop (can't be exactly sure on this as obviously I wasn't expecting anything to happen), the car began to move forward of its own accord: I definitely did not touch any of the pedals (as it was a red light that I know takes a few minutes to cycle my right foot was flat on the floor having a rest), nor any of the steering wheel buttons. I wouldn't say it 'lurched' - it was a gentle but deliberate acceleration - I was able to react immediately and get on the brake so only covered half the distance to the car in front before regaining control, but it was very definitely not a 'normal' action from the car. I cannot count the number of times (even on this same journey) that I followed exactly the same process and had no such issues. I can also say with certainty that there were no other cars moving at the time in my vicinity that may have 'tricked' the cars sensors in some way - I was in a stationary queue.
So there you have it - I can now say with certainty that there is an actual flaw in our cars that can cause them to autonomously accelerate for no apparent reason. ACC was engaged (albeit not active at the time as described above) so I wonder if there may be some bad code in that module, although I had been stationary for longer than the 'timeout' period for ACC stop/start anyway, and the car in front had not even crept forward by a millimetre so I don't see it being a phantom ACC event. I think it is more likely an issue with the signal from the accelerator pedal. I am slightly suspicious that I have only been using the auto limiter for a few weeks and have now had this experience where I never had it before, but the logical side of my brain says how could the limiter cause this? What I can say for certain is that if the gap had been half of what I had left (which would not be unreasonable in the circumstances) I would have hit the car in front!
I had no further incidents for the remaining few miles, nor on the journey home, all driven in the same circumstances, but it is safe to say that from now on I will probably cover the brake pedal more obviously when stationary, just in case!
