Door central locking causes single alarm beep and won't lock

[starris]

My driver door central locking button stopped working (seems fairly common) so I got it replaced today under warranty.
The repair seemed okay at the time as it unlocked the car fine.
However now the central locking buttons on BOTH doors cause a single alarm beep, like something has been left open, and won't lock the car.
The car locks fine with the key remote.
I tried the battery disconnect reboot but no luck.

I have tried calling the MG garage that did the repair but they never answer their phone and I end up with the switchboard and when I leave a message they don't return my calls. I will keep chasing them but if anyone has a suggestion of a fix this will probably be a lot easier and quicker than relying on the garage to fix it!

 

[EvTek23]

The normal issue with the horn beep is as you say a door, bonnet or rear hatch is open. The other time is when it detects another key in the car. But you say it locks from the keyfob.
The two systems are different, the remote keyfob is standard RF remote control locking. The keyless entry uses antennas in the door handles and rear hatch with NFC to detect the presence of the key.
There is no possibility of the spare key left in the car ?or another similar key put in by mistake it's detecting. (Glovebox, central armrest storage, or tucked behind a sun visor)
Also when sitting in the car it doesn't have a door ajar graphic showing it's not detecting the door being closed.
Apart from that I can only think it's a programming error when they fitted the new door handle.

 

[starris]

The normal issue with the horn beep is as you say a door, bonnet or rear hatch is open. The other time is when it detects another key in the car. But you say it locks from the keyfob.
The two systems are different, the remote keyfob is standard RF remote control locking. The keyless entry uses antennas in the door handles and rear hatch with NFC to detect the presence of the key.
There is no possibility of the spare key left in the car ?or another similar key put in by mistake it's detecting. (Glovebox, central armrest storage, or tucked behind a sun visor)
Also when sitting in the car it doesn't have a door ajar graphic showing it's not detecting the door being closed.
Apart from that I can only think it's a programming error when they fitted the new door handle.

@EvTek23 Thanks for the information and suggestions.

There is only one keyfob present; the spare is at home filed away securely!

When I open the door to get out, the graphic shows the driver door open (nothing else) and when I close it the graphic goes off. I also went around opening and closing doors and boot to double check but same thing still happened.

Interesting that the doors and keys use different communications. Just in case the doors were getting confused by the presence of the one keyfob, I tried locking from the door without the keyfob being present at all. As expected the door button did nothing without the keyfob being there.

I think I'm going to have to take the car back to the garage to see if they can fix it.

 

[Martinonline]

I've just had my driver's door button replaced and, so far, not had any problems. But I have had that particular problem before though it only occurred a couple of times and then not since - and that was with the passenger's side button. I put it down to rf interference.

The fact that it now occurs on both buttons would indicate a processing error after a button has been pressed. Does the boot button work?

 

[dsimpkins]

Strange that the door button doesn't work without the key, it should allow you to lock it, but not unlock.

Have you tried locking via the iSmart app?

 

[starris]

I've just had my driver's door button replaced and, so far, not had any problems. But I have had that particular problem before though it only occurred a couple of times and then not since - and that was with the passenger's side button. I put it down to rf interference.

The fact that it now occurs on both buttons would indicate a processing error after a button has been pressed. Does the boot button work?

The boot still works fine, locked or unlocked car.

 

[starris]

Strange that the door button doesn't work without the key, it should allow you to lock it, but not unlock.

Have you tried locking via the iSmart app?

I hadn’t expected it to lock or unlock for someone pressing the button without the key, otherwise anyone could do it? I was just checking incase the door was picking up ‘interference’ and thought there was another key around, to rule it out as an option.

 

[dsimpkins]

You should be able to lock without the key, but not unlock, that's the "key" bit. I remember someone manging to lock their key in the boot by mistake.

 

[ReintjeWA]

Does the app report all doors as closed? Maybe it will indicate which door the car thinks is still open? And don’t forget the bonnet, it’ll beep for that one too.

 

[starris]

The normal issue with the horn beep is as you say a door, bonnet or rear hatch is open. The other time is when it detects another key in the car. But you say it locks from the keyfob.
The two systems are different, the remote keyfob is standard RF remote control locking. The keyless entry uses antennas in the door handles and rear hatch with NFC to detect the presence of the key.
There is no possibility of the spare key left in the car ?or another similar key put in by mistake it's detecting. (Glovebox, central armrest storage, or tucked behind a sun visor)
Also when sitting in the car it doesn't have a door ajar graphic showing it's not detecting the door being closed.
Apart from that I can only think it's a programming error when they fitted the new door handle.

@EvTek23 you were 100% spot on after all! ...
My spare keyfob is filed away safely in a plastic folder together with my car documentation. This normally sits on a shelf at home.
When I brought my car into the MG garage for the door handle replacement I brought my documentation with me... it has taken me a whole day to realise the keyfob was also in the folder and has been in the car the entire time! Whoops ...
Thanks all, especially @EvTek23, for your help.

 

[Rolfe]

I knew it!