Hi all, as the originator of this thread let me make a final detailed account of the whole story so that others can maybe profit from it.
- Bought second hand 2000 4.6l Range Rover, here in Qatar
- Was given 2 key fobs, one of which worked fine, the other had a flat battery
- Decided to be "efficient" and replace batteries in both key fobs at the same time. After doing so, neither key fob would remote-unlock the vehicle.
My understanding is that this happened because the vehicle had gone into immobilisation mode (thanks to passive immobilisation), and replacing the batteries cleared the memory from the key fobs and lost their synchronisation with the vehicle's alarm system.
From this point on it became impossible to automatically re-sync the keys with the vehicle following any number of the many suggested re-sync methods on the internet, because automatic re-syncing apparently only works when the alarm/immobilisation is de-activated.
Hence what I should have done was change the batteries in one key fob and re-synced it, and then changed the batteries in the other key-fob and re-synced it.
At this point my manual key would unlock the driver's door, but it wouldn't centrally unlock/lock, and turning the key in the ignition gave the error message "engine immobilised / press remote". Pressing key fob did nothing.
- Consulted owners manual, which said to follow the Emergence Key Access (EKA) Code procedure. Went through all the papers I'd been given but couldn't find the code, so got the local Land Rover dealer to ask headquarters. They sent an e-mail back saying "EKA Code: None"
- Then consulted the Internet (mainly
Security and Alarm System Operation & Diagnosis on Range Rover 4.0/4.6/P38A) and followed these suggestions:
: 1515 code for North American vehicles did not work
: 1234 that one lone person mentioned didn't work
: disconnecting the battery and re-connecting it with key in position II didn't work (although it did freak out the BECM a bit, which starting giving me error messages about windows not being "set" as well as the immobilisation message)
I am not sure if the door lock switches were detecting my lock/unlock turns or not. I kept an eye on the red alarm LED on the dashboard and it did not seem to change its flashing rythym when I made the turns. I was on the verge of taking off the door lining to check the switches but didn't trust myself and called the workshop instead
- Truck came and took vehicle away. Got a call from the workshop a day later saying they had got engine starting again but the key fob didn't work. In other words sticking the manual key in the drivers door worked the central locking/unlocking (not just the drivers door now), and obviously the key started the engine, but the key fob would not activate the central locking.
To be clear, at this point the red light on the key fob lit up when you pushed its buttons, so it was "alive". However the various suggested key fob re-sync methods (eg. just putting in the ignition; turning it in the door lock with different button-pushing schedules) did not work for me. I found this to be one of the most inexplicable problems and no-one else seems to have reported similar, so maybe the workshop did something funny to my BECM which prevents key re-synching.
The workshop charged $75 (the towing was free, which I was happy about. Land Rovers seems to be dodgy but they treat you nicely!)
- So now I can operate the central locking with the manual key only (the key fob does nothing) and I can start the car.
My experience seems to be fairly unique compared to most of what I have read on the Internet, so don't take this as what you should necessarily do or expect, but I hope it makes some contribution to the conversation. And may I thank everyone who responded to my question and spent the time to put up information of their own elsewhere, especially
Security and Alarm System Operation & Diagnosis on Range Rover 4.0/4.6/P38A, without which I would have been completely lost.
- Ben