Unlocking Problems Disco 4

Hi,

I have a Disco 4 that has just decided to let the locking system play up. It locks all 5 doors using the fob but will then only unlock the boot with the fob. Once I have crawled back into the car and pushed the ignition, all the doors will unlock when I push the unlock button on the driver's side. Any suggestions would be hugely appreciated

That's an odd one - have you tried a battery disconnect / reconnect? what happens if you push the unlock button on the door without the ignition on? what happens if you press & hold the unlock button on the key for >5 seconds? Have you tried the second key?

Once the doors are unlocked, have you tried pressing the unlock button on the fob?
Wonder if the unlock button is working?
Boot unlock is a different button?

Is it the same as a discovery three when water gets into the passenger foot well and there was a splice in the loom under the trim between the seat and the door which goes green and nesses up central locking?

Have you tried the other key?

Graculus said:

That's an odd one - have you tried a battery disconnect / reconnect? what happens if you push the unlock button on the door without the ignition on? what happens if you press & hold the unlock button on the key for >5 seconds? Have you tried the second key?

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Hi Graculus, thanks for taking the time to respond and please excuse the delay I have been out of mobile range. I have tried disconnecting the battery. When I push the unlock button on the door without the ignition on or press and hold the unlock button on the key for >5 seconds nothing happens. Sadly I don't have the second key. Perhaps I need to get a new one made?

The behaviour you describe seems to be a 'logic' problem rather than a hardware problem, not unlocking without the ignition on is expected behaviour (as is the disabling of the interior sensor) if the received signal is coded to unlock the liftgate only. I don't think you're going to get anywhere by carrying out wiring checks etc, the receiver is clearly operational, as is the lock control output from the CJB so yes, I agree that the best way forward is to get another key as the next diagnostic step.

lynall said:

Is it the same as a discovery three when water gets into the passenger foot well and there was a splice in the loom under the trim between the seat and the door which goes green and nesses up central locking?

Click to expand...

what he said

lynall said:

Is it the same as a discovery three when water gets into the passenger foot well and there was a splice in the loom under the trim between the seat and the door which goes green and nesses up central locking?

Click to expand...

Do you mean this > https://www.disco3.co.uk/forum/topic103468.html ?

sierrafery said:

Do you mean this > https://www.disco3.co.uk/forum/topic103468.html ?

Click to expand...

Yes that is it

lynall said:

Is it the same as a discovery three when water gets into the passenger foot well and there was a splice in the loom under the trim between the th seat and the door which goes green and nesses up central locking?

Click to expand...

The body harness is largely the same and does have the splice referred to - but the symptoms for that being the cause are loss of remote opening / closing completely as the splice is the supply (or LIN, can't remember which) to the radio receiver - which prevents any activity at all.
In this case, the vehicle is locking fully & partially unlocking together with disabling the interior sensors, which suggests that the receiver and it's wiring is not compromised. Being able to command the CJB to unlock the doors once the ignition is on also confirms the CJB is operating as expected, so it's an input logic problem, possibly the key is only transmitting 'boot open' rather than global unlock.