Hello,
The buttons on my key fob were wearing out, so I bought a new key fob (a plastic case and blank blade) for £15 from Euro Car Parts, then transplanted the circuit board and blade from the old case to the new one.
Now the new fob will unlock the doors, but not disable the immobiliser. The engine will not start with the new fob (even though it has the circuit board and blade from the previous fob).
Electronically nothing has changed - it's the same old circuit board. The only change is the new plastic case of the fob.
There's only two possible reasons I can think of for this:-
The fob (just a plastic case) contains some hidden electronic component the immobiliser needs, or
The circuit board has lost settings in the half hour while disconnected for the coin battery while I transplanted it to the new case.
How do I make the immobiliser re-recognise the same fob chip its been using for years? Fortunately I've got another working fob and key.
Thanks.
Lee.