Functional Description - Powertrain Control Module (Pcm)
The Powertrain Control Module (PCM) is the main module controlling operation of the starting system relays. When the PCM receives a CRANK command message it sends a signal to the Body Control Module (BCM) to energize the BCM controlled relay while simultaneously energizing the PCM controlled relay through in internal High Side Driver (HSD). The PCM also disables the double start over ride once the engine is started.