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Matt, Mechanical Engineer
Category: Jaguar
Satisfied Customers: 23199
Experience:  BEng hons Mech engineering, in auto industry 22 years
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I replaced battery in key fob on 54 x type jag, this was

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I replaced battery in key fob on 54 x type jag, this was because it was not responding,
it still isn't working I have to lock and unlock with key but every time I unlock with the key it sets the car alarm off until I have turned the ignition on.
Customer: replied 7 months ago.
I have been waiting for two hours for my answer to my question, why is it taking so long, not impressed?


Sorry for the extended wait time you've experienced, I've only just come online now and would like to assist you with your question.

I'd suggest to try this re-sync procedure:

1.)I would recommended that you ensure all key fobs are fitted with new batteries.
2.)Get in the car and close the drivers side door.
3.)Put the key into the ignition and turn to position I.
4.)Wait 5 seconds
5.)Turn the key quickly to position II then back to I four times. (do this only once)
6.)You should hear a single chime.
7.)Remove the Key
8.)For each Key fob in rapid succession. Press any single button on the key fob you wish to pair, you should hear a chime as each Key fob is paired with the security system. After the chime press a button on the next Key fob you wish to pair.
9.)On compleation after all keys have been programed, wait 3 minutes then check the operation of each Key fob by locking/unlocking the vehicle.

Important Note :-All the fobs that you wish to use Must be paired at the same time. Every time you operate the key as in step 5 above the code will be changed, previously programmed fobs will no longer work unless you pair them all at the same time.

Customer: replied 7 months ago.
Hi Matt tried the re-sync of my key fob on the jag, did not work? what next, would it have to be re-coded and if so who by.


OK next try doing a full reset of the car by disconnecting the battery cables and clamping them together for 10 mins. Remove both battery leads from the battery then use a nut and bolt or G-clamp to hold both battery lead terminals together.

This discharges any capacitors / memory within the ECU and around the car so ensures all memory settings are wiped clear - back to the factory default.

This will reset all the systems on the car and you may need the radio security code to get it going again, and ensure that the keys are in your hand when you re-connect the battery as the car may lock and turn on the alarm

then try running through the re-sync procedure again

if this doesn't work then yes the services of the Jaguar service tool is required

any Jag specialist should be able to cope with this as well as the dealers

Matt and other Jaguar Specialists are ready to help you