P0A78-282

P112 HYBRID VEHICLE CONTROL: HYBRID CONTROL SYSTEM: P0A78-282: Drive Motor "A" Inverter Performance

DTC P0A78-282 - 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.

If the motor inverter detects a circuit malfunction or over-voltage, the inverter transmits this information to the OVH terminal of the HV control ECU via the motor inverter over-voltage signal line.






MONITOR DESCRIPTION

If the motor inverter detects a circuit malfunction, it transmits a motor inverter over-voltage signal to the HV control ECU. Upon receiving this signal, 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. READ OUTPUT DTC (HV ECU)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch ON (IG).
(c) Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.
(d) Check if DTCs are output.

Result: DTC listed in table below is output





YES -- GO TO THE TEST INDICATED IN THE TABLE ABOVE
NO -- Continue to next step.

2. CHECK CONNECTION CONDITION OF INVERTER CONNECTOR (LOOSENESS AND POOR CONTACT)
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) Check the connection condition of the I9 and I10 inverter connectors.
OK:
Connectors have been connected securely and there is no poor connection.
(e) Reinstall the inverter cover Installation.
(f) Reinstall the service plug grip Installation.
NG -- CONNECT SECURELY
OK -- Continue to next step.

3. READ OUTPUT DTC (HV ECU)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch ON (IG).
HINT: DTCs for the interlock switch system are output when turning the power switch ON (IG) with both service plug grip and inverter cover removed.
(c) Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.
(d) Check if DTCs are output.
Result:
DTCs P0A78 (INF 282, 286) and P0A7A (INF 324) (inverter circuit malfunction) are output
NO -- REPLACE INVERTER WITH CONVERTER ASSEMBLY
YES -- Continue to next step.

4. INSPECT INVERTER WITH CONVERTER ASSEMBLY (IGCT VOLTAGE)
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) Turn the power switch ON (IG).
HINT: DTCs for the interlock switch system are output when turning the power switch ON (IG) with both service plug grip and inverter cover removed.




(e) Measure the voltage between the terminals of the inverter connector.
Standard voltage:





(f) Turn the power switch OFF.
(g) Reinstall the inverter cover Installation.
(h) Reinstall the service plug grip Installation.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE INVERTER WITH CONVERTER ASSEMBLY