1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.
  2. Welcome To LandyZone!

    LandyZone is the biggest Land Rover forum on the net. We have plenty of very knowledgable members so if you have any questions about your Land Rover or just want to connect with other Landy owners, you're in the right place.

    Registering is free and easy just click here, we hope to see you on the forums soon!

P38 rear door won't open

Discussion in 'Range Rover' started by Rock ape, Feb 8, 2020.

< Previous Thread | Next Thread >
  1. martyuk

    martyuk Well-Known Member

    Joined:
    Aug 31, 2012
    Posts:
    821
    Likes Received:
    366
    Location:
    Swindon, UK
    Don't put 12V on the Black wire - it's connected to ground and in the rear doors is only connected to the door open switch - to tell the BECM if the door is open or not.

    By default the 3 wires to the 2 locking motors are all grounded in the relay, as they are a double-coil twin contact relay to allow for polarity changes.

    The Superlocking motor is ONLY used when superlocking the vehicle, it doesn't need to be operated at all when unlocking the door.

    The Locking/Unlocking relay in the BECM holds the Orange wire to ground, and pulses 12V on the Pink wire to lock the door normally. If you superlock it, then it will first pulse the Pink wire with 12V to lock the door, then pulse BOTH the Pink and Orange/Pink with 12V to superlock. The superlocking motor only moves a spring loaded pawl (that usually stops the latch mechanism at 'Locked') out of the way so that the mechanism will move all the way to 'Superlocked'

    To unlock the door, all you need to do is ground the Pink wire, and pulse 12V on the Orange wire, and this will drive the Central Locking motor back in the unlock direction. You might need to pulse it twice, as sometimes with the resistance of the springs etc in there the first pulse will drive it back to normal 'Lock' and the second will then drive it all the way to 'Unlock'

    If you can't get the door card off whilst the door is closed, then with the front door open, you should be able to access the rear door wiring through the B pillar. Pull the rubber sheath away from the bodywork side, and then you should be able to pull the connector(s) out of the bodywork, unplug them, and then have access to the wires you need - they run directly to the latch from there.

    Hope this helps,
    Marty
     
    Grrrrrr and Mark Piercy like this.
  2. tomcat59alan

    tomcat59alan Well-Known Member

    Joined:
    Apr 3, 2011
    Posts:
    13,904
    Likes Received:
    5,365
    Location:
    wirral and triquivijate
    I stand corrected.it's not hard to admit when your wrong is iit?
     
    Grrrrrr and Mark Piercy like this.
  3. Mark Piercy

    Mark Piercy Well-Known Member

    Joined:
    Jul 11, 2016
    Posts:
    7,352
    Likes Received:
    3,425
    Location:
    sud ouest France
    get stuffed im never wong!:rolleyes:








    :p
     
    tomcat59alan likes this.
  4. tomcat59alan

    tomcat59alan Well-Known Member

    Joined:
    Apr 3, 2011
    Posts:
    13,904
    Likes Received:
    5,365
    Location:
    wirral and triquivijate
    I assumed with the plug/s disconnected it would remove the earthing from the black wire.
     
  5. pwood999

    pwood999 Well-Known Member

    Joined:
    Nov 6, 2006
    Posts:
    1,200
    Likes Received:
    412
    Location:
    Near Heathrow.
    Black wire has nothing to do with the lock motors. It's only for the "Door Open" switch.
     
< Previous Thread | Next Thread >