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) monitors the Power Take Off (PTO) system. This diagnostic will fail and the PCM will light the ETC lamp if P061A - LEVEL 2 TORQUE PERFORMANCE is active, and the PTO system is operating but the independent reading of PTO switch inputs, brake inputs, transmission inputs, and engine speed inputs indicate that the PTO system should not operating.