Ever since my BECM went in to meltdown last year and needed to be unlocked by Marty my remote locking hasn't worked. Prior to this, the remote locking worked perfectly. Since I got the BECM back I've been unable to enter the EKA code that Marty programmed in for me.

Last night Gilbertd used his Nanocom to enter it for me but the fob still didn't work. He also used the Nanocom to test my door latch and found that the key switch is dead - which explains why I couldn't enter the EKA manually.

With the EKA code entered we looked elsewhere. Another rather fancy handheld gadget determined that the fob was transmitting on the right frequency but the transmission was very weak. The LED on the fob has always flashed when the buttons are pressed.

Today, I've prised off the battery cover and changed the batteries for brand new Panasonic ones. There is still no reaction from the car when the buttons are pressed.

The antenna in the rear window is showing signs of deterioration but it still doesn't work when I put the fob right next to the receiver in the rear wing.

Gilbertd suggested making a replacement antenna from a bit of wire about 8 inches or so long. Is there any more to this than unplugging the actual antenna and jamming the wire in the socket?

If that doesn't work, does any one else have any suggestions? Is it possible to test if the receiver itself works?

"Today, I've prised off the battery cover and changed the batteries for brand new Panasonic ones. There is still no reaction from the car when the buttons are pressed. The antenna in the rear window is showing signs of deterioration but it still doesn't work when I put the fob right next to the receiver in the rear wing. Gilbertd suggested making a replacement antenna from a bit of wire about 8 inches or so long. Is there any more to this than unplugging the actual antenna and jamming the wire in the socket? If that doesn't work, does any one else have any suggestions? Is it possible to test if the receiver itself works? "

Well it could certainly still be your fob (eg the batteries/contacts) which is problematic of course... and If you have made a replacement antenna just as Gilbertd suggested and it does not really make any difference it tends to add to that suggestion. You can only really check the receiver is OK by hanging a 'scope on the output to the BECM (orange)

_

I've not tried the replacement antenna thing yet - I'm not sure how.

Do I just stick the wire in the socket on the receiver or do I need to do something else with it first? Just sticking the wire doesn't sound right to me lol

Yes it's the blue cable, just add a length of wire to it (but I doubt it will make much difference but is worth a try)

Guessing you already read:
http://www.rangerovers.net/repairdetails/becm/alarm.html

It is still much more likely to be the iffy contacts on the battery so the fob is only getting 3 Volts not 6; See #11 (para 6) on:-

https://rangerovers.pub/topic/400-so-what-makes-the-fob-and-becm-flip-out-for-no-known-reason

I'll take a look at the contacts inside the fob first then. I'll need to get a new battery cover in first though. Mine is almost destroyed now. Whoever thought cheese was a good material for them wants shooting.

Gilbertd (as well as myself, previously) tried the thing mentioned in that link of holding the lock button while locking the car manually but it didn't work.

I used Fobfix to get one of mine tested, repaired and new case etc. Would heartily recommend

If the key switch in the latch is faulty, then it might not sync up still either.

Is the 'IMMOBILISER' setting in the BECM turned on or off? If it's off, then the only way of syncing the fob is in the drivers door - which if the key switch is faulty, then it might not do it. The electrical manuals show that the BECM uses the change in state of the CDL switch to initiate the sync (and listen for the transmission from the fob) but I wonder if it needs the key switch to work aswell, so it knows that the key has been turned in the lock, rather than just the sill lock button having been moved.

Definitely check the batteries to make sure there aren't any shorts, and then also worth getting the door latch sorted and seeing if it will sync up then

I can't remember which bits you sent me last year - whether it was BECM, fob and door latch, or just the BECM/BECM + fob.

I was going to PM Marty with this but may as well put the info on here. Looking at the Nano it showed that the Right Key Switch didn't change state when the key was turned in the lock. But there are a couple of things that didn't seem quite right. The Nano also gives a reading for the Left Key Switch which it doesn't have. May be universal firmware for LHD and RHD but it just seemed odd that it was showing a state for something that wasn't there. Tried to sync the fob using the key in the hole, turn and press method but no joy which, if the key switch isn't working would explain that as it wouldn't know I'd turned the key. The other thing is that the central locking still works on the key and I would have thought that if the key switch wasn't working that wouldn't work either?

Then checked the fob for output on the spectrum analyser.against mine. It is transmitting on the correct frequency but was maybe 4-5 dB down on the level mine was showing and, as David mentions, his receive antenna etched in the rear window appears to have been damaged when window tint film was fitted. I doubt either of these are the problem as even without an antenna at all the system will still work (as demonstrated by numerous people who have disconnected the antenna). Mine will lock and unlock the car from inside the house so getting closer, like putting the fob right next to the receiver, and it should still work. I'm thinking a failed key switch means it can't be synced (yes, Immobilisation is disabled in the BeCM) and as it isn't synced the receiver won't respond to it but why does central locking work on the key? Or is that done with a combination of the mechanical linkage and the CDL switch? In which case, why is the key switch even there?

The Nanocom shows the option there for the LH Key Switch, as this is obviously in the LHF latch on a LHD vehicle. It won't show any state, and I am guessing that the LHD/RHD BECM option tells it which one to look at for key activation. (and other things - like memory seat I would imagine)

As to why the locking works... Because of the CDL switch.
The 3 switches in the latch are all mechanically driven:
The Door ajar switch is triggered when the door is opened/closed from a lever off a cam.
The CDL switch is triggered when the door is locked or unlocked, by one of the locking levers
The Key switch is triggered by a lever which moved either side off centre (the switch is open circuit when the key/lever is in the center position and then triggers the microswitch when it is turned in either direction)

So the key switch is ONLY triggered when the key is turned, and the SAME lever which triggers the key switch ALSO moves the main locking lever to lock/unlock the latch. When the locking lever is moved - whether it be by the CDL motor (if triggered by the fob for example), the sill lock button OR the key, then the latch will physically lock/unlock and the CDL microswitch will change state.

So without running through every locking mode of the vehicle (they're all listed in the ETM from memory - or maybe the workshop manual) then locking the vehicle with the key in the door, with a faulty key switch will still trigger the CDL switch and signal the BECM to lock the other doors. as it's all a manual linkage from the key barrel -> latch -> lever in the latch -> locking lever.

But instead of the BECM recognising it's been locked by the key (from activation of the key switch when the key is turned and moves all the linkages/locks the latch) it will only see the CDL switch change state - which is what would happen if you were in the vehicle and locked it with the sill lock button.

Locking with just the sill lock button will centrally lock all the doors (it's connected mechanically through a rod/lever assembly too), but it WON'T set the alarm (so that you can then unlock it from inside and open the door without it screaming at you (like it would if the alarm was set, and someone decided to break a window, unlock a door from the inside and open it).

So without the detection of the key being turned, the vehicle will still centrally lock, but it also won't set the alarm as it just thinks it's been locked from the sill lock button.

I think the BECM needs to see both the key switch AND the CDL activating for it to initiate the BECM listening for the fob code to sync.

I'd replace the door latch, check the batteries in the fob are making good contact and getting full voltage to the PCB, and then see if it will sync up.

If it STILL won't work, then I can try capturing the fob codes at some point if I'm about the area (or at summer camp if RutlandRover comes) and make sure that the code being transmitted by the fob matches what the BECM is expecting to see - I'm not sure if I had my fob checker at the time when I did the BECM unlock, but it's something I'll offer to do on every BECM that comes in now! (unlike another person across the pond who does BECM work and lists on their site that their standard unlocking doesn't even include ANY testing!)

As an aside... I'm in the middle of building a BECM bench tester... so will hopefully be able to do nearly full testing... I'm planning on including door outstations, door latches, and RF receiver in the various looms - so fingers crossed can test fobs etc all on the bench! Progress is a bit slow at the moment, as I've got plenty of other things to work on, and it's a LOT of wiring... but getting there!

That explains it then, central locking is activated by a combination of the mechanical linkage and the CDL switch. So, he's got a dodgy key switch. If you remember you sent me a couple of the encapsulated microswitch sets to replace mine to stop the dancing locks in hot weather. I've still got the one I didn't use so could fit it for Rutland Rover if the latch on a very late car is the same. It's a 51 plate, one of the very last.

I suspect that the switch could have been faulty for some time but as the fob was synced it worked prior to the BeCM going into meltdown. Once that happened and it was removed, the fob would need to be synced again but can't be as the switch isn't doing anything. For the same reason the EKA can't be entered with the key either.

This all sounds like it makes sense.

It looks as though there are two different part numbers for the latch itself. FQJ103220 up until 1999 and FQJ103260 after 1999. The wiring and connectors are different but I don't know about the microswitches/mechanical elements.

Early one has a pigtail with 2 connectors coming out of it whereas the later one has a socket on the latch itself. They are actually interchangeable if you extend the loom so it will reach the connector. The later early ones (from about late 97) also had the three microswitches encapsulated in epoxy so they are a solid block rather than 3 individual switches. It's one of these solid blocks that I've got so it should be the same as on yours.

With the door latch out, are the switches easily replaceable (plug and play) or is there soldering involved?

The early ones have a moulded socket on the latch, the version 2 (FQJ103220) had a loom and a 6 + 1 connector. The later ones which you'll have being a 2001 has a loom, and a single grey 8 way connector - of which 7 pins are used.

The switches are moulded all as one block, with the wiring coming out of the moulding - so if you are going to replace the block with one of the sets I sent Gilbertd, then you will have to solder/heatshrink in the loom.

Alternatively, I have a completely refurbished latch of the style you need on the shelf - however I'm heading away this afternoon for work, and not back home until Monday evening, so wouldn't be able to send it until next Tuesday.

I'll order the one from your website tomorrow. Cheers Marty.

New latch arrived yesterday but won't get a chance to fit it until next week some time - heading down to Devon for a long weekend with family.

The fob battery cover arrived yesterday so opened it back up to check the contacts. The contacts all looked fine but I bent them all upwards a little anyway, just to be sure. As expected, the old battery cover crumbled away and new one looks very nice indeed.

Will report back after swapping the latch out.

Fitted the latch this evening and it works a treat. Entered the EKA through the door and the remote works perfectly now.

Just need to sort out returning the old one to you now Marty.