We had a car in today with the same issue.
Carried out a major service and Ashley’s last job was to reset the service light.
The date and time were way behind, so Ashley set the date to the correct one before resetting the service token but it wouldn’t take.
We analysed the stored service tokens and you could clearly see that service token 4 (year 8) was corrupt as it had the month as 64...not a valid date. It was set twice from the data at the same mileage as the first attempt was done after a battery disconnect we think and the time zeroed out to 1/1/2000.
All the previous services were carried out via the main dealer!...so it’s not the service tool, it’s the operator not setting the clock and will brick it wether it be factory Diagnosi or aftermarket tool.
We then looked at another GTS that had a working service reset by us and what happens is you can not reset the date and time to before that of the last service reset.
Screw the reset and you screw the date and time.
Is there another fix than replacing the dash? I just got my car from my independent shop, obviously the technician that used the reset tool screwed it up. When I got the car, the date was 2091 and impossible to change. I did a battery reset, it went to 2000 and still impossible to change
Not very optimistic about ever getting my date/time back...
Hey I know this is a really old post, and I don't usually post in this forum since I am in the USA. But I have this exact same problem. I am dead certain I am following the instructions correctly, but my 2014 GTS will not allow me to set anything in that menu. It does let me set the date and time but that's it.Another thing that I just noticed is in the car configuration where you can set what to show on the display and other options , when I press on the right rotating knob on any option, it goes back to the main screen than allowing me select the values of each option, does it mean the headunit and car lost sync ?