Theory Of Operation
WARNING: This page is about a different car, the 2016 RAM 3500 HD and 2016 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.
The Powertrain Control Module (PCM) contains a set of capacitors that are used to generate the large currents need to operate the fuel injectors. The PCM monitors the voltage across these capacitors and will increment an error counter if the voltage falls below a calibratible threshold. Once the counter reaches a calibrated count threshold, this fault will set. The PCM will illuminate the MIL lamp and solidly light (not flash) the ETC Lamp in the EVIC after the diagnostic runs and fails in two consecutive drive cycles.