Problems with remote central locking

[kingdave]

Hi all,

My 2007 Fiesta is having a few problems with its remote central locking, which are temperamental - some times there are no problems at all, others it won't do what I ask.

I have tried both my normal key and the spare remote key (which has never been used so the battery should still be strong) so I guess the issue is the car rather than the fobs.

I can hit all three buttons (unlock, lock, open boot) and they work, with the exception of the lock button which I normally double press. Single press of the lock button works fine, so the car will still lock, I just prefer to double lock it for a bit of extra security. Any idea what could be the issue or how to fix it?

Thanks

[Tdci-Peter]

7 hours ago, kingdave said:

Single press of the lock button works fine, so the car will still lock, I just prefer to double lock it for a bit of extra security.

The double lock facility will fail if any of the door ajar sensors indicate a door not fully closed.

You can test the door ajar sensors by repeatedly open & closing doors (with vary degrees of firmness), and watching the interior light, or the door open warning on the dash.

You may be able to narrow it down to one door latch like this.

[kingdave]

1 hour ago, Tdci-Peter said:

The double lock facility will fail if any of the door ajar sensors indicate a door not fully closed.

You can test the door ajar sensors by repeatedly open & closing doors (with vary degrees of firmness), and watching the interior light, or the door open warning on the dash.

You may be able to narrow it down to one door latch like this.

I would probably agree with that diagnosis, however I can press the double lock and it not work, then not do anything to the car and it will work 20 seconds later. Some times it will go for a couple of weeks without working and all of a sudden start again (it wasn't working today in fact, and has just started working when I've double locked, nothing happened, waited a second then tried again)

[Tdci-Peter]

2 minutes ago, kingdave said:

Some times it will go for a couple of weeks without working and all of a sudden start again

Sounds like a poor contact, either in the door switch itself, or in one of the connectors in the line.

These can be a real pig to track down. So often I think I have the gremlin located, then it wriggles out & pops up elsewhere! As soon as you approach them with a screwdriver or a multimeter, they just hide. Sometimes you have to wait until they get bad enough to happen most or all of the time.

If it only the double lock stage, it is unlikely to be the remote receiver, a dodgy door latch is most likely. Water can get into them sometimes.

Peter.