The car has recently started having this intermittent problem were the remote fob will not work to unlock it. It might fail to work, and then work fine again after a drive. This happens with both fobs. I'd suspect a bad connection somewhere in the car. Any ideas where I should start?

 

i had the same problem, but only after very cold and damp nights... Even frosty nights here are damp as well...

 

Mine refuses to work about once every couple of weeks and it's definitely an issue with the fob itself since neither the green nor red light will flicker on fob when buttons are pressed. usually a couple taps against a hard object will sort it out, but sometimes I have to remove & reinsert the batteries to get it all sorted. Do the lights on you fob illuminate during one of your inop episodes?

 

Yes, the lights are working and I have two fobs, neither of which will unlock the card during an 'episode' so I'm certain this isn't a fob issue.

 

Is there any possibility something operating on the same or a close frequency nearby is interfering with the fob signal when this happens?

From your description, it doesn't sound like the fobs are at fault as you don't have to do anything to them other than drive and wait. Have you checked the connections to the Security & Locking Module?



If there are no harness / connection faults, reprogramming the fobs may help. I never had issues with my X300 fobs but have had an X308 that would lose the fob to security module pairing occasionally and reprogramming the fobs fixed that.

Graham

 

I've experienced this phenomenom. As near as I could work out, it had more to do with whether I carried the FOB around in my pocket all day, or left it on my desk. If pocketed, I would normally have to open the car at the driver's door key barrel, if desktop, the FOB seemed to work just fine. Yes, the FOB lights were working when the button was pressed. The first time, I noticed one of the rubber button-covers had an edge pressed down into the FOB body -Freeing it up restored proper operation. Occasionally after that, hitting the "Lock" button, even though the car was already locked, would restore operation.

Graham may well be onto it. That was a regular occurrence when parking in a particular lot at work. Since my office has moved, I have very rarely encountered the problem. On rare occasions it occurs in random locations like a grocery parking lot. Additionally, I stumbled onto the following tidbit a few weeks ago: If I press the buttons on my FOBS for the 2000 Excursion and 2007 F150 simultaneously, nothing happens. Standing in same location, press each individually and the respective truck will lock/unlock. Haven't tried it among the Jag's nor cross-feeding from Ford to Jag...but the Ford FOBs definitely blank each other.

 

Movie reprogramming the fob.

 

Yeah, I unearthed that thing the other day. Looks like I'll have to unbolt the module to get to the connector. Is disconnecting it likely to reset or mess up anything (eg. security system)? Is there volatile memory in it?

 

Maraud,
Good one.
Why did no one think of doing videos for this ages ago!

Graham

 

It has to be a programmable module which isn't affected by a disconnect or anyone could get round the security system by a battery hard reset.

To be absolutely certain before you unplug it, Jaguar programmable modules have a warning on the label.

Graham

 

Hi all, has there been a solution to the described problem? My 1995 XJR has exactly the same phenomenon with the temporarely working key fob. Reprogramming the fob did not help - the security module connector also looks OK.

Thx in advance from Germany!

 

I have had the same problem, but lately it's been pretty good. I wonder if the problem isn't in the lock itself sticking. Until it becomes enough of a problem to justify taking the mechanism out of the door I'll put up with it.

It might be a good idea to clean the connector to module as Oubadah mentioned. Just disconnect the negative battery cable first.