Thread: TD5 Mislocking

Originally Posted by Koopo900

...Any Clue or Ideas?...

Just something to note on mixing the use of the key and the fob. May not be relevant to your situation.

I purchased a D2 that would not start. The owner explained that the vehicle was lent to someone to pick up something. The the driver used the fob to close it, but used the key to open it, then got horn noises...got flustered...and started using any combo of key and fob to end the noise and get the car open. Got the car open to find vehicle would not start.

In theory you can overcome a non start issue with some combination of key turns in the drivers door or the ignition key holder - can't remember which - the code is written in the owners manual - the code can be changed - daunting when you turn to the page and find four codes, all crossed out (don't work) and the current code not written anywhere.

I took the vehicle to the local independent. He explained the situation had gone beyond using the recovery code. He said there are two computers, one controls the body (BCU) and the other controls the engine (ECU). I forget which one he said had shut down on the premise the vehicle was being stolen. That control unit can no longer be communicated with - there is no magic code that a dealer has - no reset that can be done by the company. The only solution is to find a 2nd hand unit that has not shut down, then program it to the vehicle. I got the guy to silence the code that sends the computer(s) into shut down.

Check your owners manual for your key code, just in case. Consider professional alteration to the program - although others would argue the vehicle becomes easier to steal. You can get a code reader for diagnostic purposes but I'm not sure you can alter computer code - the machine to change code may be in the domain of the professional mechanics shop.

I'm sure others with vastly greater knowledge will chime in soon.

Originally Posted by Koopo900

G'Day team,
New owner to TD5 Disco 2, no issues for the first month. Then out of the blue starts to mislock when using the remote to lock. But will lock when using central locking button inside then turning key in the door (still sounds horn though). Even better to ad to this, if I unlock the car after being parked, then lock I get no horn or mislock sound
Any Clue or Ideas?
Thanks

Not really an answer, but this is from RAVE ...

Locking
The doors are locked by pressing the lock button on the handset or by locking the vehicle from the driver's door with
the key.
In order to lock the vehicle, the following conditions must be met:

The driver's door is closed.

The ignition is off.

The fuel cut off switch is not tripped.

The bonnet is closed.

The vehicle is not super locked.

Depending on system configuration a mislock occurs if these conditions are not met. The doors may lock (depending
on condition not met) and the system may not fully arm, depending on configuration of the system. If a mislock occurs
an audible warning is emitted and the vehicle becomes partially armed.

drivers door 'could' be a problem.

if fuel cut off switch has been tripped, you can't start the car.

check bonnet and or it's switch.

If one of those things listed above isn't a problem and going from your description of using the key to lock, could potentially be a problem with the drivers door lock switch.
That is, the BCU monitors the drivers door lock position as a single unit, and all the other doors as a whole unit too. If your drivers door switch is acting up, even tho you have closed the door, BCU would think it's still open, therefore not locking the car.

Haven't had this issue on any of the D2s I own, but currently have the same problem with my little red Peugeot. Pug won't lock all the time, and the BCU monitors the state of all doors independently. Not like the D2 where drivers door and all other doors together.
On the Pug, my problem is a dodgy pass front door lock. The switch must be getting stuck or something. If I only use the drivers door and remote I get a message saying door open ... just doesn't tell you which one which is stupid because it knows which one!
Anyhow, I used the key in the front pass door to lock-unlock-lock-unlock, then left it unlocked. The locked with remote and it locks fine. If I then open the front pass door, the error routine starts again. So I have to manually lock and unlock the front pass door to use the remote to lock the car. i.e. the front pass door is playing up. Manually moving the lock must somehow reset the switch for a bit, and this could be your problem.

I would test for a similar situation with your front drivers door. if you can manually lock, but suddenly can't remotely lock, then use the key again in the drivers door and suddenly it can remotely lock, I'd say more than likely it's the drivers door switch.

The problem could be another door, but as all other doors are monitored as one, good luck finding that one!
I can't remember with the D2, but I think you can lock the car with one of the non drivers doors open. If that the case(eg. you can lock the D2 with the tailgate open) then like I said, first place to check would be drivers door lock switch .. or maybe wiring.

Note. If you are new to Disco 2 ownership, and it's a TD5, I strongly advise that a nanocom is going to be your best friend. If it's a V8, I think a good quality OBD scanner can do many things the nanocom can.
The nanocom can monitor and display if a door or other switch is active or not. That is, lets say your drivers door IS closed, but the nanocom shows it's open, then pretty much 100% guaranteed that your problem is the drivers door switch.

Not sure what is meant by mislocking. But, to sort of follow on. Mine will sometimes, not often, sullenly refuse to respond to a press on the fob. I have found that simply inserting the key in the door and turning it to lock ( doesn't trigger the alarm ) will "wake it up" and it works fine. Opening it with the key will often trigger the alarm and immobiliser, which is why I always turn it anticlockwise. My alarm is disabled, but not the immobiliser ( Nobody is going to steal my 15 yo , 360,000 k Disco ), but in any case you still need the right key to start it.
Do you have, or can you get your hands on, a Nanocom? The process mentioned by workingonit is the EKA. Emergency Key Access. It's a complete PITA, as it involves turning the key multiple times, in varying directions, following an insanely complex series of numbers, which you will get wrong. The Nanocom can read what the code actually is, but better still it can change it to something quite simple. Do that, and then if you're a nice bloke write it down for the next owner. I haven't. I have owned mine for 16 years, and I imagine the next owner will be the scrap yard, as my executor won't want it.

The only security system I have come across more idiotic than the one in the D2 is the one in the P38 Range Rover. It's one of the reasons I keep a Nanocom.

To answer the question of a Nanocom, Yes i have one, just one that was never registered, so in the process of getting Nanocom to revalidate the ID so I can get the unlock codes.
Under the BCU controls to my knowledge there is a mislock option, unsure if this just allows the overriding or just doesn't toot the horn.
And what I mean by mislocking is what the BCU data sheet describes it as "The Mislock sound alerts the driver to a failed attempt to lock thevehicle. This may be because one or more of the doors, bonnet or tail door is notcorrectly closed or the key is inserted into the ignition (any position)." But all doors have been checked as closed

Originally Posted by Koopo900

G'Day team,
New owner to TD5 Disco 2, no issues for the first month. Then out of the blue starts to mislock when using the remote to lock. But will lock when using central locking button inside then turning key in the door (still sounds horn though). Even better to ad to this, if I unlock the car after being parked, then lock I get no horn or mislock sound
Any Clue or Ideas?
Thanks

Hi, about the red part... when you say "mislock" you mean only the sonud or the doors don't lock? if it's about the sound the dash switch it's not supposed to trigger the sound at all so irrelevant.

if the doors are all locking and it's just about te sound unplug the bonnet switch and try then...if the symptom is gone the problem is there, misslock has to do with the door position monitoring switches only not with other elements so it's possible to get the misslock warning sound even if all the doors or bonnet are closed and locked but if one of theyr's switches is stuck closed or there's a short to earth on that circuit cos then for the BCU means it's open as those switches are N/C to earth with open doors and they cut the earth input to the BCU when the door/bonnet is closed if you see what i mean.

to understand the system you'll have to corroborate the part quoted from RAVE by @AK83 with the following:

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.

BLUF: I fixed it.
So in regards to mislocking, both, it was not locking and was sounding the horn.
Got my Nanocom up and running and went searching in the inputs. All the doors and bonnets readable where closed.
Firstly changed the door key locking/unlocking feature to lock/unlock all the time, and the three stage unlock (three button presses) to just one.
Now realising that it cant be any of the front doors my attention changed to the tail door, I was poking around seeing if there was anything wrong with the locking and door handle before I go rip the whole thing out, I saw the child lock I believe PFA the photo for reference and put it down shut the door and it magicallystarted working again, so not 100% sure how or why but it works now.
Thanks for the help.
signal-2025-10-14-082827.jpg

Thanks for coming back and telling us. I wish more people would do that. Err, me included....

Originally Posted by Koopo900

......
Now realising that it cant be any of the front doors my attention changed to the tail door, I was poking around seeing if there was anything wrong with the locking and door handle before I go rip the whole thing out, I saw the child lock I believe PFA the photo for reference and put it down shut the door and it magicallystarted working again, so not 100% sure how or why but it works now.
.....

While it's a good thing, note that it could be a bad thing too.

While not a definitive statement, why it could be 'bad' is that D2 rear door lock mechanisms are notorious for playing up and not opening, leading to a lot of heartache and headaches.

Recall that the non drivers doors don't get recorded as individual items, and any one of them can signal an open position, even tho it's physically closed, your rear door is most likely the problem. Sticking mechanism or worn parts.

Do some searching on Disco 2 rear door locks and read up on what happens and stuff.

On my D2, had same problem, door wouldn't open, rear full of stuff at the time, so unloading to get to it was a partial problem ... etc. The problem wasn't locking/unlocking, it just wouldn't open. It started only intermittently, got gradually worse then finally just wouldn't open, just intermittently(open). In the end I changed the door lock to a known good secondhand one from my parts wreck ... so didn't really cost me, but new they are madly expensive.

If you feel competent too ... pull it out, clean it up thoroughly, and lubricate it well. If you do pull it out just make sure you don't lose or break the small green rod retainer clips ... like the idiot making this reply!