keys keys keys from a 2003 156

[cc]

Hi
I have a key problem and a 156 on the driveway who's key is in parts
(Its a story) mixed in with parts from 3 other keys (not done by me)
So there are 3 key bayonets and one key circuit board.
My question is!
Ive tried opening a door lock with just the key bayonet (the part that inserts in
to the key barrel) without any circuit board. None of the bayonetes open the door.
Is this beacause it needs the circuit board in proximity or because the bayonetes werent made for this particular door..
Or the the bayonet needs the circuit board in proximity?? and i need to get a new battery for the key and the car.
cheers CC

[Craig_m67]

The bayonets (keys) only open physical locks, you don't any need power (battery) for this.

The circuit board communicates with the ECU and disables the immobiliser (and alarm if fitted), it also opens/closes the physical locks/boot/tailgate/sunroof depending on ECU programming.

One of your bayonets (keys) should open the door and steering locks.  It will NOT disable the immobiliser/alarm without the correct fob chip/programming etal.

If you can't open a physical lock, then you have the wrong blades.  Try all the physical locks, they were originally keyed identically.

The ECU can be taught multiple key fobs (I had three), but in practice most people just buy another new (2nd hand) matching fobs/locks and ECU as it's a more cost effective repair (replacement, no programming).

[bazzbazz]

Just some clarification -

There are 3 parts to the key

1/ The Key Blade - This physically will unlock the car doors and operate the ignition barrel, it does not need anything else to operate the locks or ignition barrel. If non of the keys will open the car doors or ignition barrel then none of the keys are for this car.

2/ The circuit board in Alfa 156 keys has nothing to do with starting the car, it is only for the Remote Central Locking.

3/ The part that allows the immobiliser to be bypassed correctly is the small black plastic chip that is mounted in the key FOB separate form the circuit board. (See attached photo of immobiliser chip)

So if none of the keys will physically unlock anything it is unlikely that none of the immobiliser chips will be for the car either, and no, once a chip is programmed to a car it cannot be programmed again to a different car.

The ECU can be taught multiple key fobs (I had three), but in practice most people just buy another new (2nd hand) matching fobs/locks and ECU as it's a more cost effective repair (replacement, no programming).

This would be the best option to resolve your current situation.