Operation - Data Bus Communication Receive - Pcm Input
WARNING: This page is about a different car, the 2003 Dodge Intrepid, 2003 Chrysler Intrepid, 2003 Chrysler Concorde, and 2003 Chrysler 300M. However, it is still accessible from the selected car via links, so may be relevant.
The PCM uses the SCI communication bus to preform engine diagnostics and flash operations. The transmission side of the PCM uses the SCI communication bus to flash new software. However, diagnostics is performed via the vehicles J1850 bus for the transmission side of the PCM.