Do you need to reprogramme the immobilizer if you change the key barrel?

Yes, if you change the key barrel in a vehicle, you may need to reprogram the immobilizer system to ensure that the new key works properly. This is because the immobilizer is typically linked to the original key's transponder, which communicates with the vehicle's security system. If the new key barrel does not match the existing system, the vehicle may not start until the immobilizer is reprogrammed to recognize the new key. Always consult the vehicle’s manual or a professional locksmith for specific instructions.