P0A7A-344

P112 HYBRID VEHICLE CONTROL: HYBRID CONTROL SYSTEM: P0A7A-344: Generator Inverter Performance

DTC P0A7A-344 - Generator Inverter Performance

DESCRIPTION

See the description of the inverter P0A78.

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 HV control ECU controls MG1 torque in accordance with the driving condition.






MONITOR DESCRIPTION

If the difference between the requested MG1 torque and the actual MG1 torque exceeds a predetermined value, the HV control ECU determines that there is a malfunction in the execution or monitoring of the MG1 torque. Then, the HV control ECU illuminates the MIL and sets a DTC.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS





COMPONENT OPERATING RANGE





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.
- When measuring insulation resistance using a megohmmeter, set the megohmmeter to 500 V.

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 P0A7A (INF 344) and other DTCs are output
HINT: If any other codes besides P0A7A (INF 344) are output, perform troubleshooting for those DTCs first.

YES -- GO TO RELEVANT DTC CHART
NO -- Continue to next step.

2. CHECK HYBRID VEHICLE GENERATOR ASSEMBLY
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 if the three-phase alternating current cable installation bolts on the hybrid vehicle generator are tightened to the specified torque.
Torque: 8.0 Nm (82 kgf-cm, 71 in-lbf)
NG -- TIGHTEN THEM TO SPECIFIED TORQUE
OK -- Continue to next step.

3. INSPECT HYBRID VEHICLE GENERATOR ASSEMBLY
CAUTION: Wear insulated gloves before performing the following operation.
(a) Check that the service plug grip and inverter cover have been removed.




(b) Disconnect the three-phase alternating current cable for the hybrid vehicle generator from the inverter.
(c) Using a milliohm meter, measure the resistance between the three-phase alternating current cable terminals of the hybrid vehicle generator.
NOTE: If the generator temperature is too high, the resistance varies considerably, which hinders determining malfunction. Therefore, measure the resistance at a minimum 8 hours after the vehicle has been stopped.

Standard resistance:





- *: Apply the formula given below to correct the resistance.
- R20 = Rt / {1 + 0.00393 x (T - 20)}
- R20: Resistance converted to 68°F (20°C) (mOhms)
- Rt: Resistance between measured lines (mOhms)
- T: Ambient air temperature during measurement (°C)
(d) Calculate the difference between the maximum and minimum resistance between terminals U - V, V - W, and W - U.
Standard resistance:
Below 2 mOhms
(e) Using a megohmmeter set to 500 V, measure the insulation resistance between the three-phase alternating current cable terminals of the hybrid vehicle generator and the body ground.
NOTE: Be sure to set the megohmmeter to 500 V when performing this test. Using a setting higher than 500 V can result in damage to the component being inspected.

Standard resistance:





(f) Reconnect the three-phase alternating current cable for the hybrid vehicle generator.
(g) Reinstall the inverter cover Installation.
(h) Reinstall the service plug grip Installation.
NG -- REPLACE HYBRID VEHICLE GENERATOR ASSEMBLY
OK -- REPLACE INVERTER WITH CONVERTER ASSEMBLY