Power and Ground Distribution: Description and Operation
CIRCUIT OPERATIONCircuit Z12 connects to cavities 10 and 50 of the Powertrain Control Module (PCM) connector. The Z12 circuits provides ground for the PCM internal drivers that operate high current devices like injectors and ignition coils.
Internal to the PCM, the power (device) ground circuit connects to the PCM sensor return circuit from circuit K4.