The most reliable, efficient, and accurate means to diagnose the power lock system requires the use of a scan tool and the proper Diagnostic Procedures manual. The scan tool can provide confirmation that the Control Area Network (CAN) is functional, that all of the electronic modules are sending and receiving the proper messages on the CAN data bus, and that the power lock motors are being sent the proper hard wired outputs by the relays for them to perform their power lock system functions.