DTC P0657: Description

The DTC P0657 sets when the powertrain control module (PCM) has determined that the control module has an internal fault in the ignition voltage supply circuit 1. The PCM performs continuous self checks of all internal circuits. The PCM provides ignition positive voltage to the throttle actuator control (TAC) motor on circuit 1. The DTC P0657 diagnostic monitors the internal voltage of circuit 1.