Td5 Horn sounding when lock button pressed.

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Phill013

New Member
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20
Location
Manchester
Hi I have a 2003 discovery 2 TD5, I have done a search around google for my problem there's loads of threads but not many answers. I press the lock button on either key and the horn sounds once but the door doesn't lock. I did have a dodgy drivers lock but have changed that for a new one. I have gone around all doors opening them to see if the internal lights come on and then goes off as they are supposed too and they do, I have disconnected the bonnet switch to eliminate that. But it still does it. Every now and again it works but it's not very often. I have to lock it with the internal switch then lock the drivers door with the key. I have reset the bulkhead switch. I think the next step is to get it on a computer. Anyone have any ideas or have I missed something??. Cheers guys :)
 
I thought that but I believe the alarm uses the central locking uses the same system as the interior lights and they all work, and by disconnecting the bonnet switch the car sees it as permanently closed.
 
The horn bipping is the mislock indicator - the alarm def reckons something isn't closed properly.

I can't comment on whether the alarm uses the central locking as input sensors, but if you have a read of RAVE you'll find out for sure.

HTH
 
Cheers for your replys guys iv scoured the various forums and really am struggling one thread says you cam disconnect the bonnet sensor and it will think its closed rave says the bcu looks for 0 yo 2 volts which says there should be a circuit. Iv tested my switch and is just a on off micro switch. Think im going to have to get it hooked up to give me a clue.
 
Have just brought home today A disco 2 yr2002, auto,.
Replaced my 1996 300Tsi auto,in great condition being a jap import/.
Anyway my problem is the same. All locks lock/unlock from inside switch.
When I press lock button outside, horn sounds and doors don't lock.
Lock doors except driver from inside then lock drivers door with key and the horn sounds but all doors are locked. Can unlock doors from outside ok.
|As for as I can test everything else works on the car.
Any help appreciated

Jim A.
 
Have just brought home today A disco 2 yr2002, auto,.
Replaced my 1996 300Tsi auto,in great condition being a jap import/.
Anyway my problem is the same. All locks lock/unlock from inside switch.
When I press lock button outside, horn sounds and doors don't lock.
Lock doors except driver from inside then lock drivers door with key and the horn sounds but all doors are locked. Can unlock doors from outside ok.
|As for as I can test everything else works on the car.
Any help appreciated

Jim A.

you tried pressing the lock button twice to lock all doors.
 
Yes, I think I have tried that. Also the horn is so strident I don't want to try again tonight. Reading about the locks on back door and bonnet, do I really have to BANG them shut to make sure they work properly.
Have just seen my old Disco 1 for sale and getting nostalgic already.
Thanks

Jim A
 
Hi I have a 2003 discovery 2 TD5, I have done a search around google for my problem there's loads of threads but not many answers. I press the lock button on either key and the horn sounds once but the door doesn't lock. I did have a dodgy drivers lock but have changed that for a new one. I have gone around all doors opening them to see if the internal lights come on and then goes off as they are supposed too and they do, I have disconnected the bonnet switch to eliminate that. But it still does it. Every now and again it works but it's not very often. I have to lock it with the internal switch then lock the drivers door with the key. I have reset the bulkhead switch. I think the next step is to get it on a computer. Anyone have any ideas or have I missed something??. Cheers guys :)

just confirm, did you try that courtesy light function with ALL the doors + taildoor one by one? and it works on each of them?

cos all the door switches, as the bonnet switch are normally open when the doors/bonnet are closed so when you open any of them an earth is sent to the BCU to indicate it's open...

so if the courtesy lighting works normal by opening each door one at a time it means that the BCU gets all the inputs and if it still gives you the misslock theres some trouble with it(works normally means it doesnt stay on for 10 minutes just for 15 seconds).......you have to turn ignition on after each attempt to reset the timer in the BCU, or there's a short to ground on the bonnet switch's wiring somewhere cos that's the only one which does affect the alarm but doesnt affect the courtesy lights ..albeit it must partially arm even with the bonnet open...so the BCU is suspect anyway
RAVE said:
Partial arming
Partial arming allows protection of as much of the vehicle as possible if the alarm is armed with one or more doors or
the bonnet open.
Partial arming allows the vehicle alarm to be armed even if the following conditions exist. When the bonnet or door is
closed, the BCU activates the perimetric alarm and the volumetric alarm after 15 seconds have elapsed:
l The bonnet is not closed: If the bonnet is open when the alarm is armed, the BCU activates super locking and
volumetric sensing. In this condition, the alarm enters a partially armed state. All other functions of the alarm are
active and the BCU monitors the bonnet for a change of state. If the bonnet closes, the system is completely
armed.
l The passenger door, a rear door or the tail door is not closed: If a door is open when the alarm is armed, the BCU
does not activate super locking or volumetric sensing. In this condition the alarm enters a partially armed state.
All other alarm functions are armed and the BCU monitors the open door. If the door closes volumetric sensing
and super locking become active.
l Failure of a door latch switch: If a short circuit in the door latch switch occurs, the BCU presumes the door is not
closed. In this situation the BCU does not activate super locking or volumetric sensing. All other alarm functions
are armed.
l Damaged wiring harness: If a short circuit in the wiring harness for the door latch switch occurs, the BCU
presumes the door is not closed and does not activate super locking or volumetric sensing; all other alarm
functions are armed. If an open circuit in the wiring harness for the door latch switch occurs, the BCU presumes
the door is closed and arms the alarm as normal.
 
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After 9 years learning about disco 1's now I have to start all over with Disco 2's.
Johnny, what do you do with the switch? and exactly where is it on the wing.
thanks for the help already

Jim A.
 
Iv had 10 mins on a computer today all door locks function ok we turned the alarm functions off it now opens the doors by pressing the key but wont lock. Iv just ordered a BEARMACH HAWKEYE DIAGNOSTIC to try and sus it out as my access to a computer is limited.
 
wish you'd said you were thinking of buying a hawkeye - I'm selling mine as I've just bought a Testbook tool (as used by Dealers) - you could have had mine and saved a fair whack ;)

Hope you track down the issue soon anyway, I know how frustrating it can be.
 
After 9 years learning about disco 1's now I have to start all over with Disco 2's.
Johnny, what do you do with the switch? and exactly where is it on the wing.
thanks for the help already

Jim A.

The switch is on the inner nearside wing rain gutter channel near the front. Its covered by a small black rubber boot. It seems to stick at times so I just give it a push a couple of times and it closes down. Haven't bothered to take the boot off it yet to see why it sticks - too many other things on the car to deal with. Probably only be a 5 minute job though (famous last words)
 
Wish I'd know Articfox I'd already bought one :-( iv come to the conclusion the BCU is playing up. Iv been using my HawkEye ( it's awesome ) all doors etc function fine inc the bonnet the fog lights have started to come on randomly even with the keys out when they are on the hawk eye doesn't register them on, also the relay doesn't engage iv even swapped it. Think I'll get hold of another BCU see where it goes. My concern is the sunroof leaks and the water is getting on the ecu's I'll have to get a look.
 
Do you have a rechargable torch etc plugged into either cigar sockets???

Don't know how old this thread is, but just been to try this fix given above. I did plug my rechargeable torch in before I set off this aft, unable to lock back home, Found this fix, torch unplugged and all's well, locked and no problem. Thanks stchris356.
 
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