Right got one working one, and one that after non use can only start car (remote lock unlock wont work)

read that before changing battery to try re-initialize it steps are clear, but am worried that it will screw up fully working key

would best bet be trying to re initialize already working key, followed immediately by non working key

get into car close doors-turn key to position one , take out key after max 5 seconds-then press unlock button and at same time in sequence the center round button 3 times with a few seconds interval between pushes, and then release buttons...this should lock and unlock doors it says...just dang concerned got 1 fully working key and may mess that up too....


anyway done it this way in case of one bad oem key and been successful?

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E53 X5 3.0d SUV prod.date 11/2004 eng.variant M57N Europe Right hand drive N