FOB only locks, will not unlock
 

Hey guys,

Having an issue with my 96 disco1, key fob locks the doors (central locking all works) but will not unlock.
key in door will lock and unlock all the doors as expected.

multimeter check at the chip on the key fob circuit board shows it is getting the correct 3V as i push the unlock button, so the solder/traces appear to be intact.

Any ideas on what might be the issue?

Thanks

Have you tried a new battery in fob?

yes, confirmed no change with a new battery as expected

Now you have me wondering about those tiny little springs inside the door. Perhaps they may need replacing. When the key is used it creates enough resistance to lock/unlock.
But not with the fob. Search the forum for these tiny lock/unlock springs as this my get you closer to resolving this issue. :)

It could be the miniature tact switch in the FOB came unsoldered from the circuit board or isn't working at all.
I had that happen with my Disco 2 FOB. It was an easy fix by soldering another mini tact switch back onto the circuit board. The switch cost a $1 for 10 and took a month to get here from China.

What little springs are you referring to?
I don't hear any relays clicking when i press the fob unlock either, so I'm not sure anything is getting a signal.

I confirmed with a multimeter that the switch on the fob is working (I did fix the cracked solder joint at the battery contact to the board already) so i don't think a replacement will help here.
but wow a month, you are patient! amazon prime has me trained to be unwilling to wait over a couple days for any shipment.


Where is the receiver end of the FOB signal in the truck? is there a chance that there are failed solder joints on that board? I already had to fix the window ECU solder joints so can there be a similar issue on the unlock signal traces on the receiver board?

These are the springs:

I posted on a thread awhile ago and got this response about alarm module location
https://landroverforums.com/forum/di...ey-fobs-91229/

gc3. I'm afraid I don't have an easy answer for you, but I'd point you to the electrical troubleshooting manual for your 1996 (etlj960x.pdf, start on page 291) for more detail on the system. The Theft Alarm Unit (component Z163) resides behind the glove box.

All the manuals can be found in the google drive folder linked in my signature.

so it seems i now have a 100% working fob... assuming i hold the fob right up against the door.
so yay, problem solved. not sure if i changed anything or if it was purely a range issue

On my to-do-list is to get to the alarm module and attach a more improved antenna for the better than 1ft range.