“Engine start not possible” message

[SteveA29]

Hi folks,

Looking for any advice on an issue with my 2020 M4 which has all of a sudden developed a problem with a key.

Key fob has been in everyday use (Key1), but after a week without use, the key has stopped starting the engine. The key will unlock the car, and when the start button is pushed, the ignition comes on, but then I get the message “engine start not possible” is displayed on the dash and screen. No previous warning there was anything amiss with the key.

So I used the spare key (Key2), and the car starts fine, as you’d expect.

I was dubious that it was the battery in the original key, as the message wasn’t the usual ‘key not found’ and placing it on the steering column sensor didn’t do anything either.

Nevertheless, I’ve replaced the battery and that hasn’t made a difference.


What is odd (to me at least) is that if I start the car with both keys in it, then remove Key2 and drive off up the village, the car recognised that Key1 (the defective one) is in the car- the key profile info in the iDrive shows this. There are no warnings on the dash to say the key is not in the vehicle. As soon as the engine is turned off, and the doors locked with Key1, then unlocked, the car will not start again with Key1 - ignition and everything comes on, but “Engine start not possible” appears.

Any suggestions?! Any help greatly appreciated.

[StockholM3]

Sounds odd.
You could try re-programming it and see if that helps, ie unlocking with a working key, then leaving that key outside the car while you hold the weird key with the tip (must not lay it flat) to the key marker on the steering column and repeatedly press the start button several times.
If that doesn't help you might need to take it to BMW.
Or someone here might have a better idea.

[SteveA29]

Thanks for the suggestion - No luck with that one either.

I don’t think the car is ‘rejecting’ the key as such, as it allows the ignition to turn on, just not start - almost like immobiliser issue?