P38A Remote not locking (but does unlock)

This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
You probably won’t have any sound from speakers I’ve the becm swap is even compatible someone will be on soon to confirm that as I’m not sure with the locking problems make sure your battery is fully charged while it’s off the car
 
You need a fully charged battery and the EKA. The EKA needs a fully operational lock with all 3 microswitches doing their thing. The fob will need the RF receiver plugged in to sync and I would try the old fob sync method in the door lock (if the switches are fully working) rather than relying on the sync in the ignition.

You can swap BECMs around but you need diag to do it and you'll need the fobs from the donor car and then switch the key blades over. Make sure both BECMs are highline (with an H rather than an L printed on it) or you may lose some functionality, like fog lights and memory seats.
 
Definitely sort the door locks out & verify if the FOB is actually working or not before swapping BECM.
  1. Check the battery really is charged, and properly connected with good ground & 12V.
  2. Do the latch microswitch checks first & fix any faulty latches.
  3. Check the microswitch status is correctly showing in BECM
  4. Clear the RF memory with Nanocom, and then check if valid code is being received.
If you really want to mess with swapping BECM, then yes it can work, but you need to consider if the donor FOB's still work, and if you have the tools to sync BECM & Thor ECU.
 
Grrrrrr said:
You need a fully charged battery and the EKA. The EKA needs a fully operational lock with all 3 microswitches doing their thing. The fob will need the RF receiver plugged in to sync and I would try the old fob sync method in the door lock (if the switches are fully working) rather than relying on the sync in the ignition.

You can swap BECMs around but you need diag to do it and you'll need the fobs from the donor car and then switch the key blades over. Make sure both BECMs are highline (with an H rather than an L printed on it) or you may lose some functionality, like fog lights and memory seats.
Click to expand...
As above ^^^^ You can swap the BECM but will need diagnostics and you will need the FOB's that go with the BECM. However, the problem may well actually be the drivers door lock micro switches, assuming that the carpet and underlay is not wet.
The alarm, if it is the B-Bus type, has an internal battery that fails which would be why it was unplugged. Best left unplugged.
 
OK - update: taken the BeCM cover off, and the top PCB is badly fried adjacent to the long grey connector, the power tracks are burnt off of the board and the glass fibre is burnt so badly it's delaminating + the long grey socket above is heat welded to the plug so I can't unplug it :-(
I can't see the circuits fed from the grey plug (C325 / C1283) being the cause as this feeds the rear lights / Indicators / door locks / aerial amp & RF receiver (according to an the 'Demystifying the P38 BeCM' article), although it would explain why the rear doors no longer unlock! The ribbon cable closest to the grey connector is also burnt, will try unsoldering one from the spare BECM logic board.
Looking at the damage to the PCB, a massive amount of current must have been pulled from the board, but I can't see anything obvious that would cause this - will have a close look at the good power board this weekend and try and work out which socket those traces went to.
I've cut out the grey socket from the board so I can remove the BeCM from the car - eBay to the rescue with a seller have a set of plugs for sale (rather than hack the loom from the 4.0 HSE apart, as I may need to perform a major swap if using the 4.0 BeCM is my only way of sorting this out without going broke).
I read somewhere that the 'power' board's are all the same - this looks to be correct comparing it to another I already had (bought originally to look at how the current sensing worked re bulb fail as I wanted to fit LED bulbs - still on the ever increasing 'to do' pile), so will try to swap it over once I've worked out where the current drain came from.
With all the rain we've had, the drivers side front carpet is soaked again - I still think it's the water shedder on the drivers side door (or should I say the lack of one) allowing water to run over the door seal onto the carpet. I'm reluctant to fit the new shedder I have until I'm sure I don't need to take it apart again.... I'm >90% sure it's not coming from the heater vent since I sorted that out.
Oh, on a better note: I've picked-up two second hand (but good) Optima 5.5 Yellow Top Starter / Deep Discharge batteries (eBay - £45 each, were used for backup generator starting) - one now fitted ready for the next attempt (seller still has some if anyone is interested - collection only in the Southampton area)
 
Zaphodbb said:
OK - update: taken the BeCM cover off, and the top PCB is badly fried adjacent to the long grey connector, the power tracks are burnt off of the board and the glass fibre is burnt so badly it's delaminating + the long grey socket above is heat welded to the plug so I can't unplug it :-(
I can't see the circuits fed from the grey plug (C325 / C1283) being the cause as this feeds the rear lights / Indicators / door locks / aerial amp & RF receiver (according to an the 'Demystifying the P38 BeCM' article), although it would explain why the rear doors no longer unlock! The ribbon cable closest to the grey connector is also burnt, will try unsoldering one from the spare BECM logic board.
Looking at the damage to the PCB, a massive amount of current must have been pulled from the board, but I can't see anything obvious that would cause this - will have a close look at the good power board this weekend and try and work out which socket those traces went to.
I've cut out the grey socket from the board so I can remove the BeCM from the car - eBay to the rescue with a seller have a set of plugs for sale (rather than hack the loom from the 4.0 HSE apart, as I may need to perform a major swap if using the 4.0 BeCM is my only way of sorting this out without going broke).
I read somewhere that the 'power' board's are all the same - this looks to be correct comparing it to another I already had (bought originally to look at how the current sensing worked re bulb fail as I wanted to fit LED bulbs - still on the ever increasing 'to do' pile), so will try to swap it over once I've worked out where the current drain came from.
With all the rain we've had, the drivers side front carpet is soaked again - I still think it's the water shedder on the drivers side door (or should I say the lack of one) allowing water to run over the door seal onto the carpet. I'm reluctant to fit the new shedder I have until I'm sure I don't need to take it apart again.... I'm >90% sure it's not coming from the heater vent since I sorted that out.
Oh, on a better note: I've picked-up two second hand (but good) Optima 5.5 Yellow Top Starter / Deep Discharge batteries (eBay - £45 each, were used for backup generator starting) - one now fitted ready for the next attempt (seller still has some if anyone is interested - collection only in the Southampton area)
Click to expand...

Not all power boards are the same but if both are Highline or Lowline (or replace Lowline with Highline) you can swap the power-board over as all the codes are in the logic board.

The big question is what fried it? Don't want to fry another one.
 
It does not take a lot to fry copper tracks and burn a pcb. Sounds like damp is the root cause of your problems.
You can swap the power boards as said above, the only difference is between Lo-Line & Hi-Line. Hi-Line can replace a Lo-Line board but not vice versa unless you are prepared to lose functionality.
 
Thank you all that have replied - cover on order (good idea PW) as this is going to take a while.
Logic board cleaned-up - tried to unsolder the ribbon connector but too risky as the pins are a very tight fit in the through-holes, so have pulled apart the top clamp and peeled off the damaged ribbon cable. I know these are supposed to be a one-time use IDC connector, but I've done this many times years ago when the first PC's came out to fit different manufacturer 5.25 floppy drives (remember those!).
Looked closely at the burnt power board - I think you are 100% correct Datatek: damp/corrosion has caused this, as I can see signs of green corrosion in places - I think I had an unwitting hand in this getting worse when I lifted the loom out from the sill area so I could clean/dry and Hammerite* the front part / foot well (small amount of surface rust). I think the remaining water in the loom has wicked via capillery action into the plug and onto the BeCM PCB. Lesson learned the hard way - copious amounts of WD40 will be deployed into the loom / close to the plugs.
Thank you Grrrr & Data for confirming the power board - the 'spare' I had is a high-line fortunately.
Just waiting for the connector plugs to arrive before I re-fit.

*Green Hammerite is a very good match for Windsor Green :)
 
Before you put the BECM back together and when it's thoroughly dry, you could treat the tracks and components with Conformal Coating which will damp proof things to some extent. Available from CPC and others.
 
Progress at last - ribbon cable swapped on the logic board and BeCM re-assembled with the spare power board. eBay source connector spliced in place of the melted large grey one - soldered and insulated with glue lined heat shrink + loom taped. Battery connected back up - lots of fiddling with remote fob button presses to enable starting, and she runs!
Have been able to bleed the cooling system through - all seems well with no leaks inside the cabin or outside from the new rad. (note - tip I read from one of the Au boards for the Thor engines: disconnect the top hose and pour the coolant into it via a funnel - tricky, but it works very well with little in the way of air locks).

However, the issues with the key fob still persist, and if anything are slightly worse in that the unlock is now very very intermittent - I did manage to lock the car twice though with it: this is the first time it has ever worked for me - It seems totally random with maybe 1 in >40 tries working. As I've said before - the LED lights when you press the buttons & I've tried another (proven working) RF receiver. I'm tempted to dismantle the fob, but having done this to another one on the past, they are really glued together well and you can damage the board if you are not very careful.

Next task is to put the trim back together in preparation for taking it for an MoT - this lapsed while I've been sorting out the unexpected water / BeCM issues.
I will pull the BeCM when the weather improves and spray conformal coating in a few areas (good idea Datatek) if I can find the can - bought this years age when I was doing component level repairs. BTW there is coating on the board, but not around the soldered connector pins. I will also seal around the BeCM lid 'screws' (the machine threaded ones) - I noticed the lid holes are larger than needed and have gaps where the Torx bolts doesn't cover the lid hole: the burnt power board had signs of corrosion around a couple of the power / switching mosfets where water must have got it previously.
 
I had previously swapped it over from the known good working 4.0l HSE - however, given that water had been getting in from the air vent / cabin filter, I'll now look closely at the cabling and connectors in the footwell, they could be corroded. Job for Saturday.
 
Well, there was corrosion on some of the pins on the footwell connectors: cleaned them up and applied contact cleaner, but that hasn't solved it. Also tried swapping over the door station - again no change. New water shedder now fitted to the drivers door.
Also, my heat exchanger swap has a slight weep from the silicone pipes where they fit on the exchanger connectors, so have ordered different clamps as I think the constant pressure ones I fitted must not be a tight enough fit - hey-ho. Still pleased on how that went. I also need to swap the accelerator cable over as the one on the car is stiff - fortunately the one on the HSE is good: new ones seem to be unavailable.
Lots more to do......
 
Zaphodbb said:
Well, there was corrosion on some of the pins on the footwell connectors: cleaned them up and applied contact cleaner, but that hasn't solved it. Also tried swapping over the door station - again no change. New water shedder now fitted to the drivers door.
Also, my heat exchanger swap has a slight weep from the silicone pipes where they fit on the exchanger connectors, so have ordered different clamps as I think the constant pressure ones I fitted must not be a tight enough fit - hey-ho. Still pleased on how that went. I also need to swap the accelerator cable over as the one on the car is stiff - fortunately the one on the HSE is good: new ones seem to be unavailable.
Lots more to do......
Click to expand...
Cleaning the footwell connectors rarely produces a fix, cut the connectors out one wire at a time, solder and insulate with glue filled heat shrink.
 
It's been a while - life getting in the way again: have fixed the rear wiper (bad motor) and the headlamp & rear screen wash (bad pumps) with the parts I salvaged from the now scrapped Blue 4.0 HSE. I've also replaced the engine to heater hoses & the hoses that feed the LPG reduced/evaporator (slight weeping) only to find I now have a weep from the evaporator hose connectors (Prins VSI 235kw) so that's another job to add to the list.
On the plus side I finally got fed-up with the key-fob not working and hacksawed it open to find someone had been in it before, and made a pretty poor attempt at replacing the buttons and had also bypassed one of the PCB tracks with a badly soldered wire (which I can't see why it was done). Anyway - buttons re-soldered and wire 'repair' undone, it it works (finally!) - now to find a better after-market fob case as the one I bought doesn't lock closed the key blade properly.
I've also bought two NOS genuine RR key fobs off of eBay - does anyone know of someone who can program these?
 
Zaphodbb said:
It's been a while - life getting in the way again: have fixed the rear wiper (bad motor) and the headlamp & rear screen wash (bad pumps) with the parts I salvaged from the now scrapped Blue 4.0 HSE. I've also replaced the engine to heater hoses & the hoses that feed the LPG reduced/evaporator (slight weeping) only to find I now have a weep from the evaporator hose connectors (Prins VSI 235kw) so that's another job to add to the list.
On the plus side I finally got fed-up with the key-fob not working and hacksawed it open to find someone had been in it before, and made a pretty poor attempt at replacing the buttons and had also bypassed one of the PCB tracks with a badly soldered wire (which I can't see why it was done). Anyway - buttons re-soldered and wire 'repair' undone, it it works (finally!) - now to find a better after-market fob case as the one I bought doesn't lock closed the key blade properly.
I've also bought two NOS genuine RR key fobs off of eBay - does anyone know of someone who can program these?
Click to expand...
Unfortunately it's not possible to re-program the key fobs. You can still buy a genuine key fob from JLR for about £250.
 
nigelbb said:
Unfortunately it's not possible to re-program the key fobs. You can still buy a genuine key fob from JLR for about £250.
Click to expand...
As Nigel says, the P38 FOB cannot be reprogrammed. If you have the equipment, the chip can be transferred from your FOB to the new one. No need for a hacksaw to open the FOB case, a penknife and small hammer working along the seam will open the case with minimal damage.
 
Thank you both for the confirmation re second hand key fobs: I had read this. However, maybe I didn't make myself clear: these key fobs are NOS - new-old-stock - i.e. brand new, never been used ones. I've looked very closely at them and they are not knock-offs - inside the battery compartment the board looks exactly as it should: same as my very used one, except they are totally new & clean. They come with the correct stickers re fob 1 to 4, a proper (loose) blank key and new roll-pin to fit it to the flick-out assy. ~£16 each.
So, do we think a dealership can still program these?
I'll try the penknife/hammer on the next one I need to take apart - bit late now for this one ;-)

Oh, and I also bought & fitted one of P38 parts shop RF receiver filters (cut's out false BCM triggering) - definatly made a difference to the time the car battery lasts charged if the vehicle isn't used for a while.
 
You must log in or register to reply here.

Similar threads

I
L322 Range Rover 2005 - rear doors, tailgate, fuel cap locked
Replies
1
Views
579
pwood999
pwood999
awkwardbob
L322 2003 remote locking locked !
Replies
3
Views
439
Mark Piercy
Mark Piercy
D
Disco 4 (LR4) Faulty remote locking and unlocking
Replies
7
Views
399
Dave.d
D
I
Replacing/repairing BCU (Body Control Unit) on 2005 RR HSE
Replies
9
Views
389
invisible999
I
300bhp/ton
P38A EKA woes....
Replies
16
Views
1K
Datatek
Datatek
Back
Top