P0A78-304

P112 HYBRID VEHICLE CONTROL: HYBRID CONTROL SYSTEM: P0A78-304: Drive Motor "A" Inverter Performance

DTC P0A78-304 - Drive Motor "A" Inverter Performance

DTC P0A78-305 - Drive Motor "A" Inverter Performance

DTC P0A78-507 - Drive Motor "A" Inverter Performance

DESCRIPTION

The inverter converts the high-voltage direct current of the HV battery and the alternating current for the MG1/MG2. The inverter contains a three-phase bridge circuit, which consists of 6 power transistors each for the MG1 and the MG2, in order to convert the direct current and the three-phase alternating current. The HV control 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 HV control ECU.





The HV control ECU uses a voltage sensor, which has been built into the inverter, to detect the high voltage after boost control.





The inverter voltage sensor outputs a 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 HV control ECU monitors the inverter voltage and detects a malfunction.

Upon receiving a motor gate shutdown signal from the HV control ECU, the inverter forcefully stops the operation of the MG2 by turning OFF the power transistors that are actuating the MG2.
The HV control ECU monitors the motor gate shutdown signal line and detects a malfunction.






MONITOR DESCRIPTION

The HV control ECU monitors the motor gate shutdown (MSDN) signal line. If the HV control ECU detects an open or short malfunction of the MSDN signal circuit, the HV control ECU illuminates the MIL and sets a DTC.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS





COMPONENT OPERATING RANGE





WIRING DIAGRAM





INSPECTION PROCEDURE
CAUTION:
- Before inspecting the high-voltage system, take safety precautions to prevent electrical shocks, such as wearing insulated gloves and removing the service plug grip. After removing the service plug grip, put it in your pocket to prevent other technicians from reconnecting it while you are servicing the high-voltage system.
- After disconnecting the service plug grip, wait for at least 5 minutes before touching any of the high-voltage connectors or terminals.
HINT: At least 5 minutes are required to discharge the high-voltage condenser inside the inverter.

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - INVERTER)




(a) Disconnect the H15 HV control ECU connector.
(b) Measure the voltage between the terminal of the HV control ECU connector and body ground.
Standard voltage:






NG -- CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - INVERTER)
OK -- Continue to next step.

2. CHECK INVERTER AND HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - INVERTER)




CAUTION: Wear insulated gloves before performing the following operation.
(a) Turn the power switch OFF.
(b) Remove the service plug grip Removal.
NOTE: Turning the power switch ON (READY) with the service plug grip removed could cause malfunction. Therefore, never turn the power switch ON (READY) in this state.
(c) Remove the inverter cover Removal.
(d) Measure the resistance between the wire harness side connectors.
Standard resistance:





NOTE: When measuring the resistance, wait until the value is stable before reading the tester.

OK -- REPLACE HYBRID VEHICLE CONTROL ECU
NG -- Continue to next step.

3. CHECK INVERTER AND HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - INVERTER)




(a) Disconnect the I10 inverter connector.
(b) Measure the resistance between the wire harness side connectors and body ground.
Standard resistance (Check for open):






Standard resistance (Check for short):





(c) Reinstall the inverter cover Installation.
(d) Reinstall the service plug grip Installation.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE INVERTER WITH CONVERTER ASSEMBLY
4. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - INVERTER)




CAUTION: Wear insulated gloves before performing the following operation.
(a) Turn the power switch OFF.
(b) Remove the service plug grip Removal.
NOTE: Turning the power switch ON (READY) with the service plug grip removed could cause malfunction. Therefore, never turn the power switch ON (READY) in this state.
(c) Remove the inverter cover Removal.
(d) Measure the resistance between the wire harness side connectors.
HINT: DTCs for the interlock switch system are output when the power switch is turned ON (READY) while the service plug grip and inverter cover are removed.

Standard voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE INVERTER WITH CONVERTER ASSEMBLY