Door lock error, immobilised fault

My 1998 p38 4.6 has an ongoing door lock problem . The fobs are long gone so I manually lock / unlock the truck . I have not been able to confidently lock the truck lately , it locks fine but upon unlocking I can be restricted to just the drivers door unlocking , the rest remain locked and I get an " immobilised fault " and cant start the truck until I can get the central locking to work again , 10 mins of locking / unlocking key . Very annoying and probably a wiring fault .

Has anyone had this issue ? Ive had the door off and looked into the problem but before I take the door lock unit apart, I thought I would put it to the group . Maybe someone has documented how to take apart , clean / fix and put back together the connector ?

Thanks .

It's probably the microswitches in the door latch itself. They are known to fail over time - and if you are relying on using the key to get in, then it's necessary to have all the microswitches working.

I refurbish door latches here in the UK - so have them apart all the time. The internals are all fairly simple - a bunch of plastic parts to make up the mechanism, and then 3 microswitches. On a 1998, it's probably the second version of the latch - and more than likely will have 3 microswitches all moulded together and a short loom coming out of the latch to 2 connectors. If so, they can be a pain to replace as you can't get the moulded units, you have to replace them with 3 individual switches. On the latches I refurbish, I pin 3 switches together with threaded rod, and then drill new holes in the casing etc to get them lines up with the mechanical mechanisms so they trigger properly. There were some earlier loom ones that had 3 individual switches inside, before the went to moulded blocks - which are easy to replace.

If you can send a picture of the latch (even in the door is fine) I can identify what version it is and let you know how much of a pain it's going to be to repair.

I would consider - if you plan on keeping the RR, and just using the key to lock/unlock - actually buying a brand new latch (they're available here in the UK - someone like island4x4 will ship internationally, or I can supply refurbished one even) as going second-hand and then having to rely on the microswitches behaving is a bit of a gamble. At least if you have a new one, then you know it's going to be good for years to come.

If the vehicle is immobilised and requiring the EKA, only the drivers door will unlock with the key, so that aspect of the behaviour is "normal".
What you need to track down is why it's suddenly started to go into alarmed mode when locked. It could still be the drivers door latch microswitches at fault. @martyuk is the door latch king and has produced a test sheet for checking the latch microswitches. He also refurbishes and sells door latches through his webstore
http://p38webshop.co.uk/
As you don't use the fob, I take it you've removed the RF receiver in rear loadspace to eliminate spurious RF triggering, and have a good fully charged battery on the car?

EDIT- and Marty replied as I was typing this!

I was guessing that being Byron Bay, and there's some sunshine in the picture, that it's in Australia...

In which case, the EKA is probably not enabled, as it wasn't turned on by default on the AU market vehicles (at least the early ones) - likewise passive immobilisation isn't generally enabled.
My best guess on the issue is that either the CDL or Key switches have become intermittent, and thus when unlocking it sometimes either doesn't see it as the door moving the the unlocked position (CDL switch failing) or it's not seeing it being unlocked with the key (Key switch failing).
If the CDL is failing - it won't detect door being unlocked, and thus won't trigger other doors to unlock/vehicle to disarm and allow starting.
If key switch is failing then it will see door being unlocked, but won't see it's being done with the key (will be like using the sill lock button from inside the vehicle) and also won't disarm and allow starting, as that would be like smashing a window and unlocking it.

Either way, the issue is in the switches in the latch. If you can sometimes get lucky after a few turns of the key and it will then unlock and allow you to start, then again points to intermittent switch(es)

Thanks for the information ! Yes I will be keeping the truck , recently drove from Byron Bay to Melbourne ( 20 hours ) and she didn't miss a beat , such a nice ride ! I will replace the latch . Here are some images of the door . Do you happen to know the part number I will be chasing ?

Thanks

I think you misunderstood Marty, he needs a picture of the latch even if it is still in the door. So pop the door card off and take a snap!

Yes, A picture of the door latch and wiring going to it if you can. As Saint.V8 says - the door card needs to come off for that.

I can tell from the wiring as to what version of latch it is, and how much of a pain it is to replace the switches separately. Likewise, I can also tell you what the part number is that you need if you wish to replace it.

maybe this is my fault on mine intresting read that