P0A78-503

L110F HYBRID VEHICLE CONTROL: HYBRID CONTROL SYSTEM: P0A78-503,P0A78-504: Drive Motor "A" Inverter Performance

DTC P0A78-503 - Drive Motor "A" Inverter Performance

DTC P0A78-504 - 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.

If an overvoltage occurs in the motor inverter, the MG ECU detects it and transmits this information to the hybrid vehicle control ECU.






MONITOR DESCRIPTION

If the motor inverter detects overvoltage, it will transmit an overvoltage signal to the MG ECU. The MG ECU will send information about the malfunction to the hybrid vehicle control ECU. Upon receiving this information, the hybrid vehicle control ECU will illuminate the MIL and set a DTC.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS





COMPONENT OPERATING RANGE





WIRING DIAGRAM





INSPECTION PROCEDURE
CAUTION:
- Before inspecting the high-voltage system or disconnecting the low voltage connector of the inverter with converter assembly, take safety precautions such as wearing insulated gloves and removing the service plug grip to prevent electrical shocks. After removing the service plug grip, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.
- After disconnecting the service plug grip, wait for at least 10 minutes before touching any of the high-voltage connectors or terminals. After waiting for 10 minutes, check the voltage at the terminals in the inspection point in the inverter with converter assembly. The voltage should be 0 V before beginning work.
HINT: Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

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:










HINT:
- *1: If any INF codes are output for this DTC, refer to the corresponding diagnostic flowchart.
- P0A78-503 or P0A78-504 may be set due to a malfunction which also causes DTCs in the preceding table to be set. In this case, first troubleshoot the output DTCs in the preceding table. Then, perform a test to attempt to reproduce the problems, and check that no DTCs are output.

B -- GO TO DTC CHART
A -- Continue to next step.
2. CHECK CONNECTOR CONNECTION CONDITION (INVERTER WITH CONVERTER ASSEMBLY CONNECTOR) P0A1A
NG -- CONNECT SECURELY
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - GENERATOR RESOLVER) P0A1A
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. CHECK GENERATOR RESOLVER P0A1A
NG -- CHECK CONNECTOR CONNECTION CONDITION (GENERATOR RESOLVER CONNECTOR)
OK -- Continue to next step.
5. CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - MOTOR RESOLVER) P0A1A
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
6. CHECK MOTOR RESOLVER P0A1A
NG -- CHECK CONNECTOR CONNECTION CONDITION (MOTOR RESOLVER CONNECTOR)
OK -- Continue to next step.
7. CHECK CONNECTOR CONNECTION CONDITION (GENERATOR RESOLVER CONNECTOR) P0A1A
NG -- CONNECT SECURELY
OK -- Continue to next step.
8. CHECK CONNECTOR CONNECTION CONDITION (MOTOR RESOLVER CONNECTOR) P0A1A
NG -- CONNECT SECURELY
OK -- REPLACE INVERTER WITH CONVERTER ASSEMBLY
9. CHECK CONNECTOR CONNECTION CONDITION (GENERATOR RESOLVER CONNECTOR) P0A1A
NG -- CONNECT SECURELY
OK -- Continue to next step.
10. CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - GENERATOR RESOLVER) P0A1A
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE HYBRID VEHICLE TRANSMISSION ASSEMBLY
11. CHECK CONNECTOR CONNECTION CONDITION (MOTOR RESOLVER CONNECTOR) P0A1A
NG -- CONNECT SECURELY
OK -- Continue to next step.
12. CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - MOTOR RESOLVER) P0A1A
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE HYBRID VEHICLE TRANSMISSION ASSEMBLY