Car wont lock or unlock with door handle buttons

[Kithmo]

I had button failure on passenger door of all ones. Symptom was more that the button no longer clicked at all rather than clicking and not working. I’d lay a few £ that underneath the plastic is a micro switch, the same as a cheap mouse. It was replaced under warranty with a completely new handle with a perfect colour match - without them having seen the car until fitting fyi.

FWIW, mine's never "clicked".

 

[Bam Bam]

FWIW, mine's never "clicked".

Yeah, though I know what @gazza487 means. One of our buttons was broken when we picked up the car.

The working one has something noticeable (albeit not particularly audible) that you feel when it gets pressed.

On the broken button you don't feel anything - just pushes in without that feeling that you have pressed anything.

Microswitch is probably accurate.

 

[EvTek23]

The door handle switches seem to be a weak point, at least in a certain manufacturing period. I had a failure of my drivers side door handle button. It had the classic non positive click action and was replaced under warranty. I don't use the buttons during frosty weather as I believe this is when mine failed, but use the keyfob buttons instead.
It's worth noting that the door handle switch is part of the keyless entry/operation system. This system relies on the keyfob being detected, in the same way as the keyless operation. Each of the front doors has an antenna, the proximity of the keyfob and its detection will determine if the car will unlock using the button, assuming the switch on the door actually works. Most I've read about have been replaced under warranty as they require painting and fitting, no one has been able to see what fails with the switch.
You could get a failure to detect the keyfob due to an interfering signal in the area when outside the car. This is why the manual speaks of the keyfob position in the bottom of the armrest storage in case of these instances, otherwise you wouldn't be able to activate the car either with the message
" smartkey not detected".
The buttons on the keyfob are a conventional rf remote control system using a programmed random number sequence to determine that the keyfob seen by the vehicle is the correct one before unlocking.