I have a very weird remote central locking fault.

It all started when I opened the tailgate and closed it again. When I came to lock the car, the remote fob didn't work. So I opened and closed the tailgate again and the remote worked. This continued over a few days with problem clearly related to opening and closing the tailgate.

However eventually the remote would not work at all. But the central locking worked fine on both stages if I used the key in the drivers door lock.

So I reprogrammed the keys. And hay presto, the remotes worked. Until that is, I came to open the tailgate again. Opening and closing it knocked the remote function out, almost every time but, not every time! I continued for another week reprogramming the keys after having used the tailgate.

Now however, I can't even reprogram the keys. I've also done a BCU reset and still no joy. Finally I've had the boot trims off and can't see any broken wires. I've also replaced the upper tailgate latch with a known good one, thinking it might be giving a strange signal to the BCU. However no change.

Has anyone experienced this problem before. Any advice as to where I should look next?

Thanks for your help.

James

Under the spoiler at the top of the upper boot lid is a plastic box that looks similar to an old music cassette tape, this is the aerial for the central locking...

It is wired in with a very small coaxial cable, this can get crushed as it passes through the tailgate and cause all sorts of problems, not sure where the other end of the wire goes though, fatty off roader suffered from a wire failure and I ended up soldering it to fix it, not fun when the inner wire is one very thin strand....

Good luck  Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
-Click here for Thread-
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
-Click here for Project Fatty off roader-

Amazing! Why did they put it there? That totally fits with the issue I'm experiencing. Out with the soldering iron it is! Thank you so much for that piece of information.

Location and close up....

Thank you. Massively helpful. I'll have a chance to look at it next week. I'll post to let you know how I get on.

So further investigation this evening. I have managed to find both ends of the aerial wire and isolated it and test it for continuity both end-to-end and from the center cable to the shielding and all is fine. I've had the modulate itself out and taking it apart and can see no water staining but as there is power to the module I have to conclude that the modulate itself is at fault. I've ordered a replacement let's see if it makes a difference.

i have had my RR 8 years and had locking problems for ever.
go to fill up with petrol and cant open the rear doors or the petrol cap.
R/H rear door window wont work properly.
less than a year ago i fitted a BCU out of a 2003 and every thing works fine RR 2005 4.4 petrol
Any spelling mistakes are the fault of spellchecker
Previous MG J2, CITROEN light 15 x 2 gone unfortunately
Present MERC 180e, RANGE ROVER L322, JAGUAR XJS, MERC 280SE, MG F, JAGUAR S-Type 6v 2003, jaguar s-type 8v 2004, Ford Cougar

Interesting. What year was the l322 you had problems with?

2005
the BCU in mine, part no finishes 22, the part no on the 2003 BCU i got finishes 21
these numbers have been upgraded to finish 23, so i am led to believe
so a 21/22/23 will all fit ok, but you would have to check your number, it might be completely different.
the BCU is under the front passenger seat
if you wish to remove it, move the seat all the way forward and up and it easy to remove RR 2005 4.4 petrol
Any spelling mistakes are the fault of spellchecker
Previous MG J2, CITROEN light 15 x 2 gone unfortunately
Present MERC 180e, RANGE ROVER L322, JAGUAR XJS, MERC 280SE, MG F, JAGUAR S-Type 6v 2003, jaguar s-type 8v 2004, Ford Cougar

Final update: Its fixed! I tried a replacement box but nothing changed. So out with the RAVE wiring diagrams expecting things to get complicated. It couldn't have been simpler. There are three connectors to the box, the aerial lead that goes to another box in the passenger side boot, a 2 wire lead that connects to the rear window element, and a three wire connector. This has a power supply from the rear fuse box, a signal wire to the BCU and a signal wire to the audio system. The first wire I tried was the power feed and, hay presto, no voltage. The fuse was good, so a bit more testing revealed a broken wire in the tailgate rubber gaiter. New wire spliced in, remote key function restored.

Thanks for all your help and hope this helps someone.

great RR 2005 4.4 petrol
Any spelling mistakes are the fault of spellchecker
Previous MG J2, CITROEN light 15 x 2 gone unfortunately
Present MERC 180e, RANGE ROVER L322, JAGUAR XJS, MERC 280SE, MG F, JAGUAR S-Type 6v 2003, jaguar s-type 8v 2004, Ford Cougar