Discovery 2 - central locking issue

Hi all, having a problem with the locking on a disco 2 (98-03 body type)

• Worked fine when i bought the car a while back
• The remote/fob started to be intermittent, working better at close range, over time i needed to be next to the car. i assumed it was the fob battery.
• After being sat still a week or two, it wouldnt open with the central locking remote at all.
  
• Works properly with key, unlocks all doors as intended
• When the car is locked, the red dash light seems to respond/pause if i press and hold the unlock button on the remote

I used the key to gain entry, turned out the vehicle battery had died. When i opened the door it was incredibly humid, felt it on my skin it was like a cloud leaving the car. The vehicle had no power at all, wouldn't start. i took the following actions since:

• vehicle battery was replaced
• fob battery was replaced
• the receiver unit was replaced with a 'tested' used unit, i added an earth wire to the third pin no help

Still not working.

• checked voltage at the receiver. Purple wire @12.37-12.38v Brown [email protected]
• checked for source of humidity, found damp carpet in both footwell corners and NSR footwell
• checked fuses/relays under bonnet and steering wheel
• checked connecting plugs near BCU, some had minor powder corrosion on a couple of pins

I tried to trace the wiring from the roof to the BCU, but am not entirely sure if i have the right connecting plug/wires. The connectors i tested at the BCU end do match in voltage with the receiver connector. Unfortunately the haynes is too vague for me to be confident i have the right wires. Any help here would be great. Im hesitant to pull the BCU out in case id need to reset something with a diagnostics tool, but am willing to have a look inside if it could give answers. Same with the drivers side fusebox, ive only checked the connectors are in place, ive not removed and inspected them.


Having dug around on forums, unless mistaken, my symptoms fit either a faulty receiver or faulty wiring rather than faulty BCU. The only thing i think maybe contradicts is that i get a pause on the dash light by holding the keyfob buttons. Again, any input here at all would be really helpful.


Unfortunately in almost 2 years of trying to fix the problem casually, it is not resolved. Its become a real problem now. The door lock barrel isnt holding up well to actually being used. Snapped a key and the lock barrel failed. Tools inside, so lost a days work. Had to have a specialist break in so i could rebuild the lock barrel, he almost couldn't get in. Im worried next time the key fails the car could end up on the scrap pile.

Cheers for reading

Hi. You need diagnostic tool to run a RF test cos if the receiver is not new you can't rely on it and as long as it's not ruled out any other action is feckles... unless you change the fusebox too on a guess

It should be in for a retest monday. Ill ask them to run the test you mention. Are there any other specific checks i should ask them to run if the receiver happens to be working? (not sure what the rf test will show and my guess is they wont be motivated) - cheers

MOT station has no diagnostic machine for our car, so ill have to book diagnostics elsewhere.

Anyone near barrow (cumbria) with a nanocom/hawkeye willing to take a look? Got a few things id like changing in the settings too (eka/immobilser/deadlocks), willing to pay of course.