I have seen a lot of this and this might sound stupid and no offence is being made to anyone but what happens is that people think they are saving themselves money and buy a fob battery off eBay and take the key apart... they install the new fob battery and the key does not work. Then they pay £70 at Landrover to have the key reprogrammed. All you need to do is to remove the sticker off the bottom of the new fob battery and then the battery will work and the key will work.

 

I know this is an old thread but wanted to share a solution I just got to this issue with my 2003 Discovery II:

Key was accidentally left on in the accessory mode for a couple of days which completely drained the battery. I didn't notice until I was ready to drive it so I hooked up my jump starter/charger to jump it off. Battery was so dead it took a couple of minutes charging at high output before it would start - attempts at starting it caused power to rapidly cut in and out to the truck. Got it started and drove for 15 minutes which was sufficient time to recharge the battery, but when I got to my destination the key fob wouldn't lock/unlock the doors. I've had dead batteries many times before with this truck (I bought it new) but this is the first time the fob stopped working after a jump start,

In an attempt to be thorough I changed the fob battery even though the red fob light was coming on when I pressed the buttons - no luck. I tried the "press the unlock button once then lock 5 times" thing and still not working.

Fortunately I've got a great relationship with the local LR dealer so I reached out to the head tech for help. His response was like "I haven't seen that issue in a long time so not exactly sure what to do but try this: unhook the ground lead from the truck's battery and touch it to the positive terminal for a few seconds which will drain any stored power in the truck's systems then reconnect it and test the fob out." I did exactly what he suggested and there was a small spark when I touched the terminals which suggested there was a little power being stored elsewhere. Reconnected and tightened the battery leads and fob started working immediately.

Hopefully this will help someone else that has the same issue I did!

 

Thanks for contributing.
welcome to the forum mate.

 

nlampley2, thanks for sharing this information as it has allowed me to reconnect my key fob after having a dead battery. Great appreciated.!!

 

just did this and successfully reconnected my fob to the car. Thanks much appreciated!

Disco 3 2005

 

The key fob fix worked exactly as described. Thank you nlampley2 for your input.

 

Where you the advice is to touch earth cable to positive cable is that with the positive still connected to the battery? Sorry to ask a daft question but won't that damage the electrics,

disco 2 TD5 a bit like triggers broom!

 

As long as you don’t have the negative side of the battery connected you won’t damage anything.

 

Thanks Havlr, so the correct procedure is to disconnect the negative terminal from the battery and then provide a separate earth connection to the positive terminal that's still connected to the battery? So sorry for the questions.

 

It doesn’t matter which you disconnect, pos, neg, or both. But, of course, pulling the neg is safe and pulling the pos is hazardous. Pull one or both and connect them together and hold it for several seconds. By doing this you are ensuring that all charge is drained from all of the components, ensuring that they are OFF OFF. It is the same as disconnecting the batt and letting it sit for an extended time. Shorting the batt leads just speeds things and ensures success.