Locking problems

Good morning. Disco 2 has a central locking problems. Press the key to lock and beeps as if a door has been left open. Does the same if you turn the key I'n the door. At moment having to lock manually but will still unlock when the key is pressed. Any ideas? Cheers

Bonnet open or faulty sensor maybe, try adjusting the bracket or some other way to make better contact.

Anaconda said:

Bonnet open or faulty sensor maybe, try adjusting the bracket or some other way to make better contact.

Click to expand...

Cheers mate. That makes sense as the alarm has been randomly going off

To rule out the bonnet switch simply unplug it and lock then, if you still get the misslock audible warning with it unplugged it's not that but a door swicth

On mine the rubber boot over the bonnet switch has gone a bit plastic-e due to age & heat under there so the plunger in the switch doesn't return properly straight away. So if I've been under the bonnet, shut it & lock the car immediately the horn sounds once but if I leave it a minute before locking it, all is well. I might try some of that Autoglym rubber reviver stuff to make it more rubbery again.

Andy Warren said:

... the plunger in the switch doesn't return properly straight away. So if I've been under the bonnet, shut it & lock the car immediately the horn sounds once but if I leave it a minute before locking it, all is well.

Click to expand...

The switch is N/C, it opens when the bonnet is closed and the plunger returns to closed circuit when the bonnet is open so if the rubber boot was the problem you should have got the misslock warning all the time... that 1 minute delay with misslock warning after the bonnet was closed is common, happenes to many, not an issue but i couldnt find any 100% logical explanation for it, i suspect that it's because the bonnet monitoring circuit is different than the one for the doors and the BCU needs a short time to calculate the voltage drop on it. I can tell you for sure that the rubber boot is no factor in this behaviour.

here's for the doors:
"The input from the door latch switches to the BCU is either zero volts or an open circuit. Zero volts indicates the door
is open. An open circuit indicates that the door is closed. When the BCU sees an open circuit, it pulls the input high
internally."

and the bonnet:

"When the bonnet is closed the bonnet activated alarm switch is in an open condition and the input to the BCU is more
than 6 volts, in which case the BCU pulls the input high internally. When the bonnet is open the bonnet activated alarm
switch is closed and the input to the BCU is less than 2 volts.
The bonnet activated alarm switch has a dedicated signal input to the BCU. This allows the BCU to identify the
position of the bonnet."

Andy Warren said:

On mine the rubber boot over the bonnet switch has gone a bit plastic-e due to age & heat under there so the plunger in the switch doesn't return properly straight away. So if I've been under the bonnet, shut it & lock the car immediately the horn sounds once but if I leave it a minute before locking it, all is well. I might try some of that Autoglym rubber reviver stuff to make it more rubbery again.

Click to expand...

My son's does this also, if you don't want the horn to sound then cycle the ignition on and off then it resets itself.