C5 Doors Unlocking not rear passenger N/S

[Garryg163]

Hi, my plip key unlocks the car ok but recently the Near Side rear door will not open using the external lever, (Have to reach inside to unlock manually)

Any ideas why this should be so?

[GiveMeABreak]

What year and model C5 would help there are three variations, better still your VIN would help.
There's a post on it here: "C5 Passenger door won't open from outside"

Here is the internal diagram for a C5 Mk 1 (2001 - Aug 2004, although the mechanism is the same for the Sept 2004 to 2007 facelift).
If the control rod (3) hasn't broken off, then it's likely the mechanism has jammed. Try (with the flat of your hand) to give it a hard wallop near the handle area and operate the remote locking / unlocking at the same time to see if that will free it. If it does, spray some silicone grease into the lock mechanism (not WD40 as that can react with some plastics , making them brittle). Failing that a replacement lock may be the answer.