The coil pack is used to convert the low voltage of the primary circuit to a high secondary voltage. This is essential for the plugs to be activated. each cylinder has an individual coil with the coil pack, which is controlled by the Powertrain Control Module (PCM).
If a short is detected in the ignition coil control circuit, the PCM sets the DTC code P0356 OBDII. The last digit of this code refers to the cylinder where the problem is occurring. The number 6 cylinder is in this code.