Ok,

2nd Discovery II owned. Thousandath time similar locking alarm issue however Here's the specifics to my somewhat difference issue and I am at a loss.

2004, 88k miles
Key Fob unlocks and locks all doors properly and Yes double checked, they are all unlocking and locking, No doors are still locked
Immobilization is not reacting to doors being unlocked,
Car is staying armed, red led blinking after doors unlocked
Under hood switch relay checked, and good
Battery volts checked and is good

Process to start vehicle; only valet key will turn drivers door tumbler, (and yes both keys look identical in the key cut except master fob looks worn) back to process; valet key, two turns to the left to disable alarm,
get into vehicle and with only FOB key, wiggle steering wheel and key and pray, 1 of 5 times it will turn the ignition and truck starts fine. The other 4 and the alarm sounds...valet key will not turn ignition (odd, seems as though maybe the worn key has also worn tumbler, which would be fine is immobalized would turn off)

So, where do I start?
, PS I live 3 hours from a dealer...so when I say any help is appreciated. I mean it!

 

Driver's door lock has a Lock-center-unlock switch. It is not changing status, so the Body Control Unit does not turn off the alarm.

On the BCU, pin c0661-22 is the unlock. That wire needs to be shorted to ground momentarily to disarm. It is a blue/gray. It can be found at connector C0460, pin 10. That is under the side panel on driver's side (left of brake). See Pix attached from RAVE.

When you turn door key, it should make the C0460 pin 10 (blue gray) short to ground. On C0459, pin 5, (same pix) the blue/green is the "arm" the alarm point, it goes to ground when key is turned the other way. Ground can be found on C0460 pin 2 (black wire). You can unplug and read toward door with ohm meter before you tear open door to replace the switch. Once you disarm, you may want to cut the blue green and the blue slate wires to prevent re-arming.

You'll need to get a new door switch most likely.

 

Thanks for the details response. Silly question. Once I disarm, if i cut the blue/green (the arm wire) should things work fine from that point on just without the alarm system? or will it cause other issues?

Do you know the door switch part number by chance? tough install?

PS, thank you!

 

Just unplug the drivers' door lock actuator and see if everything works right with the remote.

 

Like jafir says, you can disconnect and test. It involves the two connectors above, under the kick panel, or one connector inside the door, where you have to remove the whole door panel. That comes out by gently prying these one-way plastic fasteners with an upholster removal tool (plastic, cheap, at parts store). Be patient, work your way all around the edge of the door. The head of the fastener is held in the plastic foam core of the door and grandma could rip it apart. See attached for pix of door with panel off, there was a clear plastic seal across mine as well (cut and repair with duct tape).

If you just want to meter things, and have to drive the truck while you wait for parts, may not want to take the door panel on/off twice.

In the RAVE you'll find the wiring drawings in the circuits file, and the actual ocation and picture of connectors in the electrical library.

 

04 Disco SE.....and I have the same problems that JBoever described. It is extremely intermittent, but sometimes when I unlock the truck using the FOB, the alarm stays on....red light still blinking.....and the truck won't start. My fix has been to lock and unlock using the FOB and it starts right up. I read the replies above and am slightly confused. Is there a connector or two that I can unplug behind the kick panel that will disable the alarm, fix the issue, and not harm anything else? i am hoping to avoid taking off the door panel if it is not necessary. Thanks for the help.

 

Nope, can't disable without reprogramming by dealer level computer. The truck immobilses ignition every time it is shut off. When you turn the key, the BCU (alarm and other devices) exchanges a psuedo random code with the ECU, if they don't match; no engine operation. The fob use forces resync of this code. Good idea to have good batteries in the fob. If immobilised without a fob, problem escalates.

 

Thanks Savannah. What is the right fix for this issue? I have read many posts on multiple sites for this and you seem to have the best grasp on the problem. Of course.....everytime I take my truck in, the shop can't replicate the problem. It's more of a nusance than anything, but like you said, I don't want to have this happen someday and then find out the batteryin the FOB is bad too. Thanks.

 

If I owned a D2, I would pay them the time at the shop next time it was in to turn off every program option they could related to immobilization and alarm, but I live in the boonies where car doors can be left unlocked, and the neighbors all have scopes on their rifles; not a metro area where you have to be a master mechanic and take the engine block inside each night.

ROver was lilely forced into this by various other contries laws about reducing vehicle theft. I'm sure that most road wariors don't want SWMBO to be stuck with immobilized truck while they are five states away.