P0A78 / INF510
P0A78-510Description
The inverter converts high-voltage direct current from the HV battery and alternating current for MG2 and MG1. The inverter contains a three-phase bridge circuit, which consists of six power transistors each for MG2 and MG1, that converts direct current to three-phase alternating current. The MG ECU controls the actuation of the power transistors. The inverter transmits information that is necessary for effecting control, such as the amperage and voltage, to the MG ECU.
The MG ECU uses a voltage sensor, which is built into the inverter, to detect boosted high voltage to allow control of the voltage boost.
The inverter voltage sensor outputs voltage that varies between 0 and 5 V in accordance with the changes in the high voltage. The higher the high voltage, the higher the output voltage, and the lower the high voltage, the lower the output voltage.
The MG ECU monitors the inverter voltage and detects malfunctions.
DTC Logic
DTC Detection Logic
Upon receiving a motor gate shutdown signal from the MG ECU, the inverter forcibly stops MG2 by turning off all power transistors that are actuating MG2.
The MG ECU monitors the motor gate shutdown signal line and detects malfunctions.
The MG ECU monitors the current that flows in MG2. If the current flows in MG2 while the vehicle is stationary with the ignition switch ON or the shift lever in the N position, the MG ECU will detect a malfunction. The hybrid vehicle control ECU will illuminate the MIL and set a DTC.
NOTE:
- If DTC P0A78-510 is output, the hybrid system cannot be restarted until the DTC is cleared.
- If the malfunction is not reproduced, leave the vehicle for 1 minute with the shift lever in the N position in order to easily reproduce the malfunction.
Diagnostic Procedure
