Ignition Circuit Sense - Pcm Input
WARNING: This page is about a different car, the 2008 Dodge Magnum, 2008 Dodge Charger, and 2008 Chrysler 300. However, it is still accessible from the selected car via links, so may be relevant.
The ignition switch power feeds to the PCM originate from the Integrated Power Module (IPM) after it determines what position the ignition key is in. The ACC and Run/Start feeds are hard wired from the IPM to the PCM. There is no hard wire Start feed to the PCM, because the IPM indicates via a CAN bus message to the PCM when the key is in the START (Crank) position.