Theory Of Operation

WARNING: This page is about a different car, the 2015 RAM 3500 HD and 2015 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

The Variable Geometry Turbocharger (VGT) Actuator is supplied power directly from the Powertrain Control Module (PCM) using a Pulse-Width Modulated (PWM) output. This is referred to as "smart power". Smart Power is a program completely internal to the PCM. The Smart Power supplies 12 Volts to the VGT. The Smart Power Control circuit is a high side driver controlled by the PCM. The Smart Power is powered up at key on, and remains powered until just after key off. The power supply to the VGT is wired directly from the PCM. The PCM will illuminate the Malfunction Indicator Lamp (MIL) immediately after the diagnostic runs and fails (1 trip). During this time there will likely also be communication faults for the VGT. The PCM will turn off the MIL once the diagnostic runs and passes in four consecutive drive cycles.