P0A78-523

L110F HYBRID VEHICLE CONTROL: HYBRID CONTROL SYSTEM: P0A78-523: Drive Motor "A" Inverter Performance

DTC P0A78-523 - Drive Motor "A" Inverter Performance

DESCRIPTION

The inverter contains a three-phase bridge circuit, which consists of six power transistors each for MG2 and MG1. The inverter converts high-voltage direct current from the HV battery into three-phase alternating current for MG2 and MG1, it also converts three-phase alternating current supplied by MG2 and MG1 into direct current for the HV battery. The MG ECU controls the actuation of the power transistors (IGBTs). The inverter transmits information necessary for control, such as amperage and voltage, to the MG ECU.

The MG ECU uses an inverter voltage sensor, which is built into the inverter, to detect boosted high voltage to allow control of the voltage boost.
The MG ECU monitors the inverter voltage sensor and detects the following malfunctions.

HINT: When the power switch is turned off, the MG ECU applies current to MG2 in a way that does not generate torque, in order to discharge the residual voltage in the inverter. When the hybrid system is normal, the VH value is almost 0 V after discharge. This DTC will be stored if the VH value is more than the specified value after discharge.

MONITOR DESCRIPTION

The hybrid vehicle control ECU monitors the inverter voltage (VH) sensor signal. If the hybrid vehicle control ECU detects a fault in the sensor signal, the hybrid vehicle control ECU interprets this as a VH sensor failure. The hybrid vehicle control ECU will illuminate the MIL and set a DTC.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

COMPONENT OPERATING RANGE

INSPECTION PROCEDURE

PROCEDURE

1. CHECK DTC OUTPUT (HV)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.
(d) Check if DTCs are output.
Result:

B -- GO TO DTC CHART
A -- REPLACE INVERTER WITH CONVERTER ASSEMBLY