Part 1

L110 HYBRID VEHICLE CONTROL: HYBRID CONTROL SYSTEM: P0A78-286: Drive Motor "A" Inverter Performance

DTC P0A78-286 - Drive Motor "A" Inverter Performance

DESCRIPTION

The inverter converts high-voltage direct current from the HV battery and alternating current for MG2 and MG1. The inverter contains a three-phase bridge circuit, which consists of six power transistors each for MG2 and MG1, that converts direct current to three-phase alternating current. The MG 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 MG ECU.

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

If the motor inverter overheats, or has a circuit malfunction or internal short, the inverter transmits this information to the MFIV terminal of the MG ECU via the motor inverter fail signal line.

MONITOR DESCRIPTION

If the motor inverter detects a circuit malfunction, it transmits a motor inverter fail signal to the MG ECU. Upon receiving this signal, 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
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, check the voltage at 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.
- After inspection, be sure to replace 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: DTC P0A78-286 may be set due to a malfunction which also causes DTCs in the table above to be set. First troubleshoot the output DTCs in the table above. After troubleshooting all output DTCs, be sure to replace the inverter with converter assembly.

YES -- GO TO DTC CHART
NO -- Continue to next step.
2. CHECK CONNECTOR CONNECTION CONDITION (INVERTER WITH CONVERTER ASSEMBLY)
(a) Turn the power switch off.

(b) Check the connection of the low voltage connector of the inverter with converter assembly.
Result:
The connector is connected securely and there are no contact problems.
NG -- CONNECT SECURELY
OK -- Continue to next step.
3. CHECK QUANTITY OF HV COOLANT

(a) Check for coolant leaks.
(b) Check that the water filler assembly contains coolant, and the coolant in the radiator reserve tank assembly is above the low level.
Result:

HINT: After repairing the coolant leaks and adding coolant, perform the "Activate the Water Pump" and "Control the Electric Cooling Fan" active tests and make sure that there are no malfunctions.

C -- CHECK FOR COOLANT LEAKS AND ADD COOLANT
B -- ADD COOLANT
A -- Continue to next step.
4. CHECK COOLANT HOSE
(a) Check if the hoses of the cooling system are kinked or clogged.
NG -- CORRECT THE PROBLEM
OK -- Continue to next step.
5. PERFORM ACTIVE TEST USING TECHSTREAM (WATER PUMP)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Select the following menu items: Powertrain / Hybrid Control / Active Test / Activate the Water Pump.
(d) Perform the "Activate the Water Pump" active test.

(e) During the "Activate the Water Pump" active test, open the inverter radiator cap and check that there are ripples in the coolant. Continue the active test for at least 1 minute.
Result:
There are ripples in the coolant in the water filler assembly for 1 minute.
- Turning the power switch off or finishing the active test with the inverter radiator cap open will cause the coolant to overflow. Be sure to close the inverter radiator cap before turning the power switch off or finishing the active test.
- The water with motor pump assembly operates even with the power switch on (READY). However, the water with motor pump assembly will operate at low speed for 20 seconds after power switch is turned on (READY).
HINT: The water pump motor operates even in maintenance mode.

NG -- PERFORM ACTIVE TEST USING TECHSTREAM (WATER PUMP)
OK -- Continue to next step.
6. PERFORM ACTIVE TEST USING TECHSTREAM (COOLING FAN)
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Select the following menu items: Powertrain / Engine and ECT / Active Test / Control the Electric Cooling Fan.
(d) Perform the "Control the Electric Cooling Fan" active test.
OK:
The cooling fan rotates.
NG -- CHECK CONNECTOR CONNECTION CONDITION (COOLING FAN ECU CONNECTOR)
OK -- Continue to next step.
7. CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - GENERATOR RESOLVER)
CAUTION:
Be sure to wear insulated gloves.
(a) Turn the power switch off and remove the service plug grip L110 Hybrid Vehicle Control System.
NOTICE:
After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Disconnect connector A60 from the inverter with converter assembly.
(c) Turn the power switch on (IG).
(d) Measure the voltage according to the value(s) in the table below.
Standard voltage:

NOTICE:
Turning the power switch on (IG) with the low voltage connector of the inverter with converter assembly disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
8. CHECK GENERATOR RESOLVER

(a) Turn the power switch off.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open):

NG -- CHECK CONNECTOR CONNECTION CONDITION (GENERATOR RESOLVER CONNECTOR)
OK -- Continue to next step.
9. CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - MOTOR RESOLVER)
CAUTION:
Be sure to wear insulated gloves.
(a) Turn the power switch off and remove the service plug grip L110 Hybrid Vehicle Control System.
NOTICE:
After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Disconnect connector A60 from the inverter with converter assembly.
(c) Turn the power switch on (IG).
(d) Measure the voltage according to the value(s) in the table below.
NOTICE:
Turning the power switch on (IG) with the low voltage connector of the inverter with converter assembly disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

Standard voltage:

(a) Turn the power switch off.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open):

NG -- CHECK CONNECTOR CONNECTION CONDITION (MOTOR RESOLVER CONNECTOR)
OK -- Continue to next step.
11. CHECK INVERTER WITH CONVERTER ASSEMBLY (GENERATOR CABLE CONNECTION CONDITION)
CAUTION:
Be sure to wear insulated gloves.
(a) Turn the power switch off and remove the service plug grip L110 Hybrid Vehicle Control System.
NOTICE:
After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

(b) Check for arc marks at the bolts for the generator cable.
(c) Check that the bolts for the generator cable are tightened to the specified torque, the generator cable terminals are connected securely, and there are no contact problems.
NOTICE:
Make sure that the tightening torque of the bolts is between 6.4 and 9.6 N*m (65 and 98 kgf*cm, 57 and 85 in.*lbf).

Torque: 8.0 Nm (82 kgf-cm, 71in-lbf)
Result:

C -- REPLACE MALFUNCTIONING PARTS
B -- TIGHTEN TO SPECIFIED TORQUE
A -- Continue to next step.
12. CHECK INVERTER WITH CONVERTER ASSEMBLY (MOTOR CABLE CONNECTION CONDITION)
CAUTION:
Be sure to wear insulated gloves.
(a) Check that the service plug grip is not installed.

(b) Check for arc marks at the bolts for the motor cable.
(c) Check that the bolts for the motor cable are tightened to the specified torque, the motor cable terminals are connected securely, and there are no contact problems.
NOTICE:
Make sure that the tightening torque of the bolts is between 6.4 and 9.6 N*m (65 and 98 kgf*cm, 57 and 85 in.*lbf).

Torque: 8.0 Nm (82 kgf-cm, 71in-lbf)
Result:

C -- REPLACE MALFUNCTIONING PARTS
B -- TIGHTEN TO SPECIFIED TORQUE
A -- Continue to next step.
13. CHECK HYBRID VEHICLE TRANSMISSION ASSEMBLY (MG1)
CAUTION:
Be sure to wear insulated gloves.
(a) Check that the service plug grip is not installed.
(b) Disconnect the generator cable and motor cable from the inverter with converter assembly Components.

(c) Using a milliohmmeter, measure the resistance according to the value(s) in the table below. (Check MG1 for an interphase short.)
HINT: If the MG1 temperature is high, the resistance varies greatly. Therefore, measure the resistance at least 8 hours after the vehicle is stopped.

Standard resistance:

To correct the variation of the measured resistance due to temperature, use the following formula to calculate the resistance at 20°C (68°F).
R20 = Rt / {1 + 0.00393 X (T - 20)}
The calculation is based on the following:
R20: Resistance at 20°C (mOhms)
Rt: Measured resistance (mOhms)
T: Temperature when the resistance is measured (°C)
(d) Using a megohmmeter set to 500 V, measure the resistance according to the value(s) in the table below.
NOTICE:
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:

NG -- CHECK HYBRID VEHICLE TRANSMISSION ASSEMBLY (GENERATOR CABLE CONNECTION CONDITION)
OK -- Continue to next step.
14. CHECK HYBRID VEHICLE TRANSMISSION ASSEMBLY (MG2)
(a) Check that the service plug grip is not installed.
CAUTION:
Be sure to wear insulated gloves.
(b) Disconnect the generator cable and motor cable from the inverter with converter assembly Components.

(c) Using a milliohmmeter, measure the resistance according to the value(s) in the table below. (Check MG2 for an interphase short.)
HINT: If the MG2 temperature is high, the resistance varies greatly. Therefore, measure the resistance at least 8 hours after the vehicle is stopped.

Standard resistance:

To correct the variation of the measured resistance due to temperature, use the following formula to calculate the resistance at 20°C (68° F).
R20 = Rt / {1 + 0.00393 X (T - 20)}
The calculation is based on the following:
R20: Resistance at 20°C (mOhms)
Rt: Measured resistance (mOhms)
T: Temperature when the resistance is measured (° C)
(d) Using a megohmmeter set to 500 V, measure the resistance according to the value(s) in the table below.
NOTICE:
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:

NG -- CHECK HYBRID VEHICLE TRANSMISSION ASSEMBLY (MOTOR CABLE CONNECTION CONDITION)
OK -- Continue to next step.
15. CHECK CONNECTOR CONNECTION CONDITION (GENERATOR RESOLVER CONNECTOR)

(a) Check the connection of the generator resolver connector.
Result:
The connector is connected securely and there are no contact problems.
NG -- CONNECT SECURELY
OK -- Continue to next step.
16. CHECK CONNECTOR CONNECTION CONDITION (MOTOR RESOLVER CONNECTOR)

(a) Check the connection of the motor resolver connector.
Result:
The connector is connected securely and there are no contact problems.
NG -- CONNECT SECURELY
OK -- REPLACE INVERTER WITH CONVERTER ASSEMBLY
17. PERFORM ACTIVE TEST USING TECHSTREAM (WATER PUMP)

(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Select the following menu items: Powertrain / Hybrid Control / Active Test / Activate the Water Pump.
(d) Perform the "Activate the Water Pump" active test.

(a) Check the fuse (INV W/P) in the engine room R/B No. 1 for improper installation and open circuits.
Result:
The fuse is installed securely. There is no open circuit in the fuse.
NG -- CHECK CONNECTOR CONNECTION CONDITION (WATER WITH MOTOR PUMP ASSEMBLY CONNECTOR)
OK -- Continue to next step.
19. CHECK INTEGRATION RELAY

(a) Remove the integration relay from the engine room R/B No. 1.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:

NG -- REPLACE INTEGRATION RELAY
OK -- Continue to next step.
20. CHECK CONNECTOR CONNECTION CONDITION (WATER WITH MOTOR PUMP ASSEMBLY)

(a) Check the connection of the water with motor pump assembly connector.
Result:
The connector is connected securely and there are no contact problems.
NG -- CONNECT SECURELY
OK -- Continue to next step.
21. CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU CONNECTOR)
(a) Turn the power switch off.

(b) Check the connections of the hybrid vehicle control ECU connectors.
Result:
The connectors are connected securely and there are no contact problems.
NG -- CONNECT SECURELY
OK -- Continue to next step.
22. CHECK HARNESS AND CONNECTOR (WATER WITH MOTOR PUMP ASSEMBLY CIRCUIT)
(a) Remove the integration relay from the engine room R/B No. 1.

(b) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open):

Standard resistance (Check for short):

(c) Disconnect connector A49 from the water with motor pump assembly.
(d) Disconnect connector A54 from the hybrid vehicle control ECU.
(e) Measure the resistance according to the value(s) in the table below.

Standard resistance (Check for open):

Standard resistance (Check for short):

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
23. CHECK WATER WITH MOTOR PUMP ASSEMBLY

(a) Disconnect connector A54 from the hybrid vehicle control ECU.
(b) Remove the integration relay from the engine room R/B No. 1.
(c) Apply 12 V to terminal 4 of integration relay vehicle side connector 1V and check that the water with motor pump assembly operates.
OK:
The water with motor pump assembly operates.
NG -- REPLACE WATER WITH MOTOR PUMP ASSEMBLY
OK -- REPLACE HYBRID VEHICLE CONTROL ECU