P0A93

L110 HYBRID VEHICLE CONTROL: HYBRID CONTROL SYSTEM: P0A93-346: Inverter Cooling System Performance
P0A93-346 - Inverter Cooling System Performance

DESCRIPTION

The inverter converts the boosted high-voltage direct-current from the HV battery into alternating current for MG2 and MG1. The inverter generates heat during the conversion process, and this heat could damage the inverter if a cooling system is unavailable. Therefore, similar to MG2 and MG1, the inverter is cooled by a special cooling system consisting of an electric water pump, cooling fan, and radiator. This cooling system is independent of the engine cooling system. The hybrid vehicle control ECU monitors the electric water pump, cooling fan, and cooling system, and detects malfunctions.

MONITOR DESCRIPTION

If the hybrid vehicle control ECU detects a malfunction of the electric water pump, fan or radiator, the 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.

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:

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

2. CHECK CONNECTOR CONNECTION CONDITION (INVERTER WITH CONVERTER ASSEMBLY CONNECTOR)

(a) Turn the power switch off.

(b) Check the connection of the low voltage connector of the inverter with converter assembly.

OK:

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.

NOTICE:
- 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. READ VALUE USING TECHSTREAM

(a) Stop the engine and leave the vehicle for at least 1 hour.

(b) Connect the Techstream to the DLC3.

(c) Select the following menu items: Powertrain / Hybrid Control / Data List / Inverter Coolant Water Temperature, Inverter Temp (MG1), Inverter Temp (MG2), Converter Temperature.

Result:

The displayed "Inverter Coolant Water Temperature" value is at least 20°C (68°F) higher than "Inverter Temp (MG1)", "Inverter Temp (MG2)" and "Converter Temperature".

NOTICE:
The lower limit temperature that can be displayed for "Inverter Temp (MG1)", "Inverter Temp (MG2)" and "Converter Temperature" is 15°C (59°F). The lower limit temperature for "Inverter Coolant Water Temperature" is -50°C (-58°F). The "Inverter Coolant Water Temperature" value displayed on the Techstream may be lower than the others, but this is not a malfunction.

NG -- REPLACE WATER WITH MOTOR PUMP ASSEMBLY Components

YES -- REPLACE INVERTER WITH CONVERTER ASSEMBLY Service and Repair

8. PERFORM ACTIVE TEST USING TECHSTREAM (WATER PUMP)

(a) Connect the Techstream to the DLC3.

(b) Compress the inlet hose for the water with motor pump assembly several times.

(c) Turn the power switch on (IG).

(d) Select the following menu items: Powertrain / Hybrid Control / Active Test / Activate the Water Pump.

(e) Perform the "Activate the Water Pump" active test.

(f) 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.

NOTICE:
- 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 the power switch is turned on (READY).

HINT
- Keep compressing the water pump inlet hose until the coolant level in the water filler assembly stops dropping.
- The water pump motor operates even in maintenance mode.
- 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.

OK -- ADD COOLANT
NG -- Continue to next step.

9. CHECK FUSE (INV W/P)

(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.

10. CHECK INTEGRATION NO.1 RELAY (INV W/P)

(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 NO.1 RELAY
OK -- Continue to next step.

11. CHECK CONNECTOR CONNECTION CONDITION (WATER WITH MOTOR PUMP ASSEMBLY CONNECTOR)

(a) Check the connection of the water with motor pump assembly connector.

OK:

The connector is connected securely and there are no contact problems.

NG -- CONNECT SECURELY
OK -- Continue to next step.

12. CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU CONNECTOR)

(a) Check the connections of the hybrid vehicle control ECU connectors.

OK:

The connectors are connected securely and there are no contact problems.

NG -- CONNECT SECURELY
OK -- Continue to next step.

13. 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.

14. CHECK WATER WITH MOTOR PUMP ASSEMBLY

(a) Disconnect connector A54 from the hybrid vehicle control ECU.

OK:

The connector is connected securely and there are no contact problems.

NG -- CONNECT SECURELY
OK -- Continue to next step.

16. CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU CONNECTOR)

(a) Check the connections of the hybrid vehicle control ECU connectors.

OK:

The connectors are connected securely and there are no contact problems.

NG -- CONNECT SECURELY
OK -- Continue to next step.

17. 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):

Standard resistance (Check for open):

Standard resistance (Check for short):

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

18. 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 pump operates.

OK:

The water pump operates.

NG -- REPLACE WATER WITH MOTOR PUMP ASSEMBLY
OK -- Continue to next step.

19. REPLACE HYBRID VEHICLE CONTROL ECU

(a) Replace the hybrid vehicle control ECU Service and Repair.

NEXT -- REPLACE FUSE (INV W/P)

20. CONNECT SECURELY

(a) Connect the water with motor pump assembly connector securely.

NEXT -- REPLACE FUSE (INV W/P)

21. CONNECT SECURELY

(a) Connect the hybrid vehicle control ECU connector securely.

NEXT -- REPLACE FUSE (INV W/P)

22. REPAIR OR REPLACE HARNESS OR CONNECTOR

(a) Repair or replace the harness or connector.

NEXT -- REPLACE FUSE (INV W/P)

23. REPLACE WATER WITH MOTOR PUMP ASSEMBLY

(a) Replace the water with motor pump assembly Components.

NEXT -- REPLACE FUSE (INV W/P)

24. CHECK CONNECTOR CONNECTION CONDITION (COOLING FAN ECU CONNECTOR)

(a) Check the connections of the cooling fan connectors.

OK:

The connectors are connected securely and there are no contact problems.

NG -- CONNECT SECURELY
OK -- Continue to next step.

25. CHECK CONNECTOR CONNECTION CONDITION (ECM CONNECTOR)

(a) Check the connections of the ECM connectors.

OK:

The connectors are connected securely and there are no contact problems.

NG -- CONNECT SECURELY
OK -- Continue to next step.

26. CHECK COOLING FAN MOTOR

(a) Disconnect the cooling fan motor connector.

(b) Apply 12 V to the cooling fan motor and check that the cooling fan rotates.

OK:

The cooling fan rotates.

NG -- REPLACE COOLING FAN MOTOR Components
OK -- Continue to next step.

27. CHECK COOLING FAN ECU

(a) Connect the cooling fan motor connector.

(b) Disconnect the cooling fan ECU connector.

(c) Apply 12 V to the cooling fan ECU and check that the cooling fan rotates.

OK:

The cooling fan rotates.

NG -- REPLACE COOLING FAN ECU
OK -- Continue to next step.

28. CHECK HARNESS AND CONNECTOR (ECM - COOLING FAN ECU)

(a) Disconnect connector A53 from the ECM.

(b) Measure the resistance according to the value(s) in the table below.

Standard resistance (Check for open):

Standard resistance (Check for short):

(c) Remove the FAN MAIN relay from the engine room R/B No. 1.

(d) Measure the resistance according to the value(s) in the table below.

Standard resistance:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ECM Components