Dodge/Cummins ECU (1998.5 - 2002 ISB)   ECU Hardware There are 2 computers on the Ram. One on the passenger side firewall behind the air cleaner assembly (the Powertrain Control Module, or PCM), and the ECU, which is located on the left side of the engine, mounted directly on the engine block. The ECU is connected with a single 50-pin connector. The ECU itself is a sealed unit, with a single air vent device. It is constructed of an aluminum 'frame', or center section, that