Central Locking Not Working

Hello, new to the forum and looking for some help.

I have spent hours trying to get CL to work.... Twingo 2009.

Pulled every fuse from passenger side/glovebox, cleaned and inspected them (and made sure correct fuse amperage present).

Swapped black diode (looks like fuse) apparently related to CL from engine fuse box to passenger, checked engine fuses all ok.

Dash lock button works so assume CL actuator working.

Checked key sending signal with sealey fob tester. Swapped used batteries from another working fob, but not tried a new one, but assume battery ok afterall worked on other car........ Could try a new one though.

Not much info on the net about this. Wondering if one of the relays has gone, only three present in glove box.... Black, Blue and Brown... Thinking maybe the black one is related to CL.

Have read water ingress on uch on some renaults, affecting internal fuse?

Everything else working great, just no central locking!

Anyone got any suggestions, Thanks

always get elec probs on French cars lol

Still not working guys.... checked relay in glovebox as apparently my model related to it. Removed UCH as Autodata bulletin states problem with CL on Twingos, loose cables/pins corroded or component failure on uch/circuit board...

No obvious signs of corrosion so put it back in... Didnt have time to do any tests...

Plan to take it off again and check continuity from uch board pins to uch connectors... If that is ok then it must be a component in the uch has failed or key recognition issue which is out of my capabilities....