On a 2001 ford focus zx3 the keyless trunk entry doesn't work

Use your key to unlock the door / trunk. If your car starts up; it might just be a connector and / or your battery in your remote. Try the simple / cheaper fix check by checking the connectors leading to the trunk release solenoid.

If the system is not working even when you press the buttons on the door, then the problem is not with the remote control. I would first check if all the fuses are ok, if they are, I would check the wiring on the door to make sure there are no wires broken of chaffed. Focus first on getting the system working with the door buttons and after that is ok, the move on to the keyless system in case it still does not work. Hope this helps.

NEVER MIND WHAT FUSE, CHECK ALL FUSES, WITH A FUSE TESTER, IGNITION SWITCH ON. FUSES ARE UNDER THE HOOD & IN THE DASH

The 5 digit entry code is in the trunk, on the left hinge arm that holds the trunk lid.

The keyless entry matches to the module for it that is mounted under the dash. It may have gone bad since your remote will not function. Of course it could be your remote as well that went bad

i assume you meen fulepump its in the trunk behind either the passenger side panel or drivers

there is a recall on them i had the same issue it is caused by the wires being crushed when the trunk colses(im an ex ford mechanic, and ex owner of a focus)

Check your fuse box, look on the diagram and locate the fuse (10 amp most likely) for the auto trunk. The clicking is the relay, it also operates the keylees entry for the doors.

Good luck

a loose or damaged wire is causing a short circuit!
you ned to get it tested & rectified by a auto electrician ASAP!
as wiring gets very hot & can destroy your vehicle! {catch fire]

Sounds like a short circuit here ? You will need to locate the short circuit . Most probable is the tail lamps and their connections , then number plate lights , then any hinged wiring going from body to a door or trunk (ie No plate illum lights) area . Sometimes the dash dimmer can be a problem . Good luck