Central Locking Module?

[Projectuno 7]

I have an issue with my central locking whereby it does not work anymore when I turn the key in the drivers door.

 

I have tried replacing the drivers door actuator with a known working one but it has made no difference.

 

Is there such a thing as a 'central locking module' located under the dash, if so where can I find it and who has a spare they can sell me?

[Ryan 99]

On phase 2 models there's a control unit under the steering column, just above the driver's left knee. It's a black box a couple of inches long.