DTC P0657: General Description
Main CPU and driver ICs are built into the powertrain control module (PCM). The main CPU receives drive commands and driver IC drives each corresponding devices. Power for the main CPU is provided from +B P/P VBU line via CPU power supply, and power for the driver ICs are provided from FI MAIN RLY OUT line via PGM-FI main relay 1 circuit. If the FI MAIN RLY OUT voltage is a specified voltage for a specified time, the PCM detects a malfunction and stores a DTC.