rufport2

I had to replace my ignition lock cylinder and received a new pass key with the purchase.Is there any instructions on how I can reprogram my Vehicle to recognize the the new ignition and key, My Vehicle is a 1998 C5

rufport2

Can someone please walk me thru how to reprogram my 1998 C5 so it will recognize the new lock and key.

3sACROWD

Does the new key have the same resistance in the pellet? If yes, just install new switch. If not, is there a reason you are replacing the old key? If the old key isn't worn, it would be easier to have the tumblers changed in the ignition switch cylinder. (I had mine done for $20 at a local key shop). Keeping your old key keeps functionality with the rest of the locks on the car.

Not sure how to reprogram the BCM to accept new key resistance. Someone else will have to chime in.

rufport2

Thanks 3sACROWD this has resolved the issue foe me. The forum is a great resource.

SkinS

I realize this thread is 4 years old but hoping #sACROWD is still reading it.
How do you know if the new switch will have the same resistance as your old key? I dont want to change the door locks just replace the tumbler in the ignition cylinder?

Smoken1

If you re-key the new switch to fit your old key you will be fine

mmartinez

The switch doesn't have resistance, only the key has the resistor pellet.

3sACROWD

Agreed. Think of the ignition switch as a place to plug in the key resistor. The BCM then reads the key resistor value and if a match will allow the car to start. The tumblers in the switch are mechanical and the profile of the key has to match the tumblers for the cylinder to turn.