Thread: Key Fob Battery

As far as I am aware you should be able to as it is the unpowered micro chip in the fob that talks to the immobilizer - however you need a battery in the fob to unlock the car to get in, unless you go in through the emergency route via the passenger door.

Originally Posted by 101RRS

As far as I am aware you should be able to as it is the unpowered micro chip in the fob that talks to the immobilizer - however you need a battery in the fob to unlock the car to get in, unless you go in through the emergency route via the passenger door.

Thanks , thats what i thought might be the case but could not find any info in the handbook .

Not a Landrover but a Mitsubishi - the fob was broken with a cracked circuit board. The chip which is unpowered (like in your dog) was at the key blade end and would still start the car. Later when we got a new key fob we removed the chip from the old key and holding the chip up to the steering column using a key blade the car would still start.

My understanding is the LR fob works the same and the smarts are in the powered electronics which are just to unlock the doors and do whatever else it is programmed for - now I am talking D3 - not sure of later D4s which may be different.

Originally Posted by Fatso

Can you start disco 3 with key fob flat battery . Thanks 4 any info .

If you have a working key you can use an elastic band or tape to attach your not working key to the working one they charge by proximity it should charge alittle drive around for a while and then give it a go. Genuine keys aren’t too dear nowadays @400 or you can get aftermarket ones that have replaceable batteries. If you have a iid tool you can code your own if you have a working one.

Originally Posted by landrovermick

If you have a working key you can use an elastic band or tape to attach your not working key to the working one they charge by proximity it should charge alittle drive around for a while and then give it a go. Genuine keys aren’t too dear nowadays @400 or you can get aftermarket ones that have replaceable batteries. If you have a iid tool you can code your own if you have a working one.

Yep thanks for that , no probs at moment just wanted to know if a key fob with a dud battery can actually start the car as can with other makes , could not find anything in handbook .

Originally Posted by Fatso

Yep thanks for that , no probs at moment just wanted to know if a key fob with a dud battery can actually start the car as can with other makes , could not find anything in handbook .

It will start it but won’t open it. You can open the door via the emergency entry on the passenger handle but the alarm will go off until you turn the ignition.

Originally Posted by landrovermick

You can open the door via the emergency entry on the passenger handle but the alarm will go off until you turn the ignition.

Or you hit the unlock button on the centre dash (D3).