I have just finished fitting OEM remote locking to my 2003 Mk2 and it all works wonderfully. However, I have discovered that when I have the doors locked and I open the boot using the key fob, it sets the alarm off. I assume this is not supposed to happen, but I would like confirmation from someone who has OEM remote locking on an NB to confirm.
If the doors are unlocked, no issue. If the car is locked and I open the boot by putting the key in the slot, no issue. I suspect it may be happening because of the power source I chose to splice into and it causing a brief voltage drop which freaks the alarm out, but for all I know it might just be how the alarm is supposed to function.
It wasn’t a kit, I had to source all the parts from eBay and FB marketplace. The keyless module, key and electric boot latch are pretty easy to source. Finding OEM connectors (for the boot release relay for instance) was the hard part.
no, it shouldn’t happen. You can press the little boot button on the OEM remote and the boot will pop open, the rest of the car will remain locked, the alarm silent.
The boot can remain open with no impact on the alarm.
Thank you sir!
The only thing I have done differently to the wiring diagram is run the power from the room fuse instead of the door locks fuse. As I mentioned in the original post, I think the voltage fluctuation caused by the boot release might be tripping the alarm for some reason. I might try running power directly from the battery with its own remote inline fuse. I can’t think what else could be causing it.
I didn’t have chance to take a look at it today, but my running theory is:
The key barrel for the boot has a microswitch in it which disables the alarm when the key turns a tiny amount (before the switch for the boot light activates and before the latch opens). The actuator is supposed to turn the key barrel - as if there was a key in it - via the metal rod/linkage and therefore disable the alarm in the exact same way. I think this metal rod needs adjusting/bending because right now there is too much slack in the system and the actuator is trying to turn on the lights and pop the latch before the alarm is deactivated, causing it to trip.
If yours has factory fitted OEM remote locking and has the same issue then it reinforces my theory that it’s a problem with the physical mechanism rather than the wiring!
No luck. The key barrel microswitch I mentioned is activated (by the key) separately/before the lever rotates so it isn’t that. I did however notice that there is wire (green & red) coming from the key barrel in the boot which terminates at the connector just above it. I have a feeling this wire is potentially the solution, but I can’t find any wiring diagrams that show where it is supposed to go (probably because of security reasons).
Follow those wires to the first connector. It should be right above the key barrel. Those 3 wires go in, but the green/red stops there. The other 2 become a blue/white and a solid black which I assume is a ground.
I can’t seem to find any reference to these wires anywhere on the internet, but I assume they hold the key (no pun intended) to solving the alarm issue.
That wire and the associated switch are very reliable, as almost impossible for water ingress. Similar wires/switches cause far more of a problem on the doors. Very easy to test; as already mentioned, if there is issue here it will very likely be articulation of the switch rather than the switch itself.
These wires and switches, if faulty or rather not operating correctly will set off the alarm.
I’m guessing here as I don’t have a wiring diagram to hand but I reckon that as your car didn’t have keyless entry from build its lacking the wire in the main loom to continue the green/red wire back to the alarm control module. If you can give me a few days I’ll confirm what should do what. Give me a nudge towards the end of the week if you’ve heard nothing.
Edit… actually that doesn’t make sense as your issue is when you open the boot with the transmitter isn’t it…
Correct. I know for a fact that the key barrel has something to do with the issue as I can stop the alarm triggering by inserting the key and turning it 45 degrees or so which is obviously disarming the alarm. This happens before the lever attached to the latch/key barrel even moves. At this stage I can pop the boot with the fob and not set off the alarm. As long as the microswitch in the key barrel is engaged with the initial turn of the key, I can do whatever I like to the switch on the latch and the latch itself and the alarm won’t trigger. I’ve also discovered that the alarm triggers if all the doors are locked and you open the boot using the pull cable inside the car. This confirms that the issue isn’t anything to do with the wiring I added as all that stuff was of course already present. I’ve also tried disconnecting the connector that the key barrel plugs into and the only difference was that I could no longer disarm the alarm via the key in the slot. I have seen 1 or 2 pictures/videos of cars which came with remote boot release and they seem to have no wires at all coming from the adjacent key barrel, so perhaps these wires/this type of key barrel only exists for non-keyless cars?
Anyway, latest theory is: the initial turn of the key disarms the alarm before anything happens to the latch so either there’s a way I can link the turning of the latch with the turning of that microswitch or (more likely) the wires coming from the key barrel are supposed to somehow bypass the alarm in a different way.
I imagine that this circuit is present in the door locks as well since they also utilise actuators activated by the fob and the alarm doesn’t get set off. I’ve looked all over, but I can’t find a wiring diagram that mentions the wires on the key barrel anywhere. I’m guessing it’s for security reasons being alarm/lock related. The keyless module and central locking module don’t seem to connect directly to the key cylinder at all other than the red/white signal wire being sent to the boot latch itself.
Thank you all for the help so far. It’s rather annoying to breeze through the entire process and then hit this massively confusing hurdle right at the end, but that’s always the way it goes right!
The Red/White wire from the keyless unit is for the trunk lid opener relay. The wire should T off in the harness to arrive at terminal 2B (Red/White) at the theft deterrent control module. Check for battery voltage at 2B with the boot release button not pressed and a pulse to zero volts when the boot release button is pressed.
Can’t point you in a direction of a wiring diagram I’m afraid but I’m pretty sure that the TDM is under the shear bolted cover in the passenger footwell with the PCM. I’d guess that the wire in position 2B is missing.
Immobiliser unit is completely different. Can’t tell what the other unit is from the photo. I’m pretty sure the TDM is with the PCM, I’m away until Wednesday but will be able to confirm after then.
I shall take a look at mine tomorrow
