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Home >> Lexus >> 2008 >> RX 400h FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 160 (Hybrid Vehicle Control (P310) - RX400H - DTC P0A37-258 Through P0A79-812) >> DTC P0A78-266 Drive Motor "A" Inverter Performance: DTC P0A78-267 Drive Motor "A" Inverter Performance >> Description

DTC P0A78-266 Drive Motor "A" Inverter Performance: DTC P0A78-267 Drive Motor "A" Inverter Performance: Description

WARNING: This page is about a different car, the 2006 Lexus RX 400h. However, it is still accessible from the selected car via links, so may be relevant.

The inverter converts high-voltage direct current from the HV battery and alternating current for the Motor and Generator. The inverter contains a three-phase bridge circuit, which consists of six power transistors each for the Motor and the Generator, 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.

Fig 1: Description Of Drive Motor "A" Inverter Performance System Diagram
G04112002Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

The MG ECU uses a voltage sensor, which is built into the inverter, to detect boosted high voltage for boost control.

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 a malfunction.

DTC DETECTION TROUBLE CONDITION

DTC No. INF Code DTC Detection Condition Trouble Area
P0A78 266 Open or short to GND in the inverter voltage (VH) signal line w/ converter inverter assembly (MG ECU)
267 Short to +B in the inverter voltage (VH) signal line w/ converter inverter assembly (MG ECU)