Car is not starting "Put Key into Backup Position" after door change

[fasak]

Hi guys I have tried to search the forum, but I was not able to find a solution for this my driver's side door had a hit and I replaced the door with a similar car but now the car does not start, and it says that “put key into backup position” also the “smart key is not found” . I have only one key what I've tried so far is to change the batteries of the key unplug the 12 Volt battery and put the key into the middle of the where you put the cups now this is 2021 MG 5 EV long range and I don't know what to do The Body Shop guy is really wants to remove the car from garage so you can do the other work. I can’t move the car the handbrake is on, the steering wheel is locked I don't know what to do and if anybody can suggest something what needs to be done that will be really really helpful

 

[Pete G]

Temporarily you could use a trolley jack to move the car out of the workshop.
It sounds like there may be a key detector in the door that has not been changed over from the old door.
Have a look in the old door and see if there is a module there that needs to be swapped over.
Pete

 

[decrep]

strange place for a key detector, but makes sense. Hope the old door hasn't gone to the tip!

 

[Pete G]

I don't actually know where the key detector is in the cars, but it seems like circumstantial evidence that you changed the door now the car won't work.
Does the Key unlock and lock the doors. That would give a clue to whether the sensor is in the door.
If you can lock and unlock the car then I would be looking at the switch that tells the car that the door is closed. Or maybe plug was accidentally disconnected when the door was changed.
Pete

 

[MG Clive]

I don't think you'll get away with just swapping a door, you'll probably need to swap all the electronics and sensors and door handle from the old door as well, was it all working correctly with the old door?

 

[fasak]

Quick update, i was quoted £300 for one key and apparently modules need reprogramming, and the current key will never work as car is gone into theft prevention mode as the door was removed while 12v battery was connected. MG dealer was useless as they dont come out and my car was stuck in the body shop I manage to reset the same key i had, i used Xtool D8 which i bought 2 years ago and this was the first major test of the tool, and it was successful, now the second thing I will be doing is to buy a spare key from eBay and program it, let’s see if that works. Thanks for all the inputs.

 

[MG Clive]

Some progress anyway @fasak , please let us know how you get on with your second key.

 

[decrep]

Seems like there are real traps working on these cars.
I guess the lesson from this is to undo the -ve battery terminal before doing any work to the car.
That should be in big letters somewhere prominent.