* Locked out: Try your spare key. If you don't have a spare, you'll need a locksmith or a dealership to help you regain access.
* Keyless entry problems: If you have a keyless remote, check its battery. The remote may also need to be reprogrammed to the vehicle. This usually requires a dealership visit or a specialized scan tool.
* Faulty door lock actuators: One or more of the door lock mechanisms may be malfunctioning. This requires mechanical repair.
* Electrical problems: A problem in the car's electrical system could be interfering with the locking mechanism. This would require professional diagnosis.
If you're thinking of a different type of code (like a security code for an aftermarket alarm system), you'll need to consult your alarm system's manual or contact the alarm system installer for instructions.
