if it has a mat on the drivers floor, check that it is secured to the main carpet, if not secure it or remove it. Loose mats are known to cause problems the same as you described, check it out before you take it to the garage.
I know you have checked the footwell for foreign bodies and I’m not trying to teach you to suck eggs but did your check include checking mats? They do move around and before you got to check the car, your daughter may have moved the mat clear as she waited that couple of minutes or when she got out of the car.
It’s a ‘fly-by-wire’ throttle system; look for a bad connection, eg ground pin on the the pedal plug or +ve supply on the TPS etc. Maybe a plug (one of the many!) is not fully seated in its socket and a bit of warmth or movement is enough to break connection.
If a quick wiggle of the connectors is not effective take it back to the garage to sort.
There maybe codes stored in the management system that could give a clue, do you have a code reader? Otherwise as RichardFX suggests, it’s worth checking any connections including battery connections.
It’s a ‘fly-by-wire’ throttle system; look for a bad connection, eg ground pin on the the pedal plug or +ve supply on the TPS etc. Maybe a plug (one of the many!) is not fully seated in its socket and a bit of warmth or movement is enough to break connection.
If a quick wiggle of the connectors is not effective take it back to the garage to sort.
Good luck!
update ,
returned car to garage today ,
they found a fault on TPS, reset fault + ( cleaned it ???)
says if it happens again they with fit a new TPS ( full pedal unit )
My only experience with the TPS is this. On my VAG car a SEAT I had it throw up warning lights on the dash, plugged my code reader in and it threw up TPS at fault. It was the opposite though of what your daughter has experienced, the car lost power, went into limp mode. Stop the car turn the ignition and restart cleared the problem, but it happened again at random, maybe with a few days or even a couple of weeks inbetween. It got to the stage I had to take it in to the local garage to have a look, he hooked it up to his computer and diagnosed TPS but he didn’t believe it, he then tested the battery and told me it was low on power thus not sending the correct signals back to various gizmos like the TPS. He said he sees it a good deal on VAG cars, a new battery sorted the problem and I’ve never had another problem with it. The TPS would have cost me £112 to buy + fitting but it wasn’t at fault of course I had to buy a new battery.
Just get the battery tested before shelling out on any other parts, especially if it’s an old one.
I hope that is the end of the problem but bearing in mind the nature of the issue, would insist the TPS be replaced if there is even a hint of a further problem.
A car randomly revving to 7K would perplex me let alone a young female, presumably with limited driving experience. The alternative scenario of limp mode is almost as bad.
A replacement, new TPS was the obvious answer but perhaps these parts require special order.
Sincerely hope that is the end of the matter and a Happy New Year to you and yours.
