Vehicles are equipped with the COP (Coil on Plug) system to provide the ignition spark necessary for the right engine operation. In this system, the coil checks that the engine operates in a specific way to use a spark plug wire for ignition. These ignition coils are electronically controlled by the Powertrain Control Module (PCM).
The DTC P0357 OBDII code is related to the electrical circuit between the PCM and the ignition coil. If any recorded voltage has a difference of more than 10% from the values already set by the manufacturer, this code will be set and the Check Engine light will illuminate.