I need to change the batteries in the key fob as the central locking is not working (3years plus since last battery change) I understand the immobiliser uses the key fob for authentication.
As car is off road and this is last set of keys which has not lost coding I am concerned about losing the code.
Should I change them with the engine running or would this not make much of a difference?
Also can I get spare key/fobs coded to match working key without taking the vehicle into dealers?