Cooling System [10/2022 - ]: Procedure

1. Make sure that the front side of the radiator grille is not blocked with anything.
2. Ask the customer if the front side of the radiator grille was blocked with anything.

   Result

   Result	Proceed to
   Not blocked.	A
   Is/was blocked.	B

   HINT: 

   If the radiator grille is blocked, the inverter coolant temperature will increase and this DTC may be stored.

Result: 

B 

IF EQUIPPED, EXPLAIN TO CUSTOMER THAT OPTIONAL COMPONENTS WILL BE REMOVED 

Result: 

A 

See step  2

1. Check the HV coolant level in the inverter reserve tank.
2. Check for HV coolant leaks.

   Result

   Result	Proceed to
   No leaks are found and the HV coolant level in the inverter reserve tank assembly is above the low line.	A
   No leaks are found and the HV coolant level in the inverter reserve tank assembly is below the low line.	B
   HV coolant leaks are evident.	C

   HINT: 

   • After repairing the HV coolant leaks and adding coolant, perform the Active Tests "Activate the Inverter Water Pump" (Hybrid Control System) and "Control the Cooling Fan Duty Ratio" (Engine Control System) and make sure that there are no malfunctions.
   • If there are signs of coolant leakage around the connecting parts of a hose and the hybrid motor control inverter assembly, replace the hose with a new one.

Result: 

B 

ADD HV COOLANT 

Result: 

C 

INSPECT FOR COOLANT LEAK AND ADD COOLANT 

Result: 

A 

See step  3

1. Check that the cooling system hoses are not kinked or clogged.

   OK

   The cooling system hoses are not kinked or clogged.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE COOLANT HOSE 

Result: 

OK 

See step  4

Pre-procedure1

• None.

• Perform the "Control the Engine Cooling Fan Duty Ratio" Active Test.

  Powertrain > Engine > Active Test 

  Tester Display
  Control the Engine Cooling Fan Duty Ratio

  OK

  GTS Operation	Fan Operation
  30 - 100%	Cooling fan operates
  0%	Cooling fan stops

  Result

  Result	Proceed to
  Cooling fan operate	A
  Cooling fan does not operate	B
  Cooling fan do not stop

Post-procedure1

• Turn the ignition switch off.

Result: 

B 

CHECK COOLING FAN SYSTEM. Refer to  Cooling Fan Circuit [10/2022 - 08/2023]  , or refer to  Cooling Fan Circuit [08/2023 - ] 

Result: 

A 

See step  5

Pre-procedure1

• None.

• Check the Grill Shutter System.

  HINT: 

  Refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2022 - ]

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None.

Result: 

NG 

CHECK GRILLE SHUTTER SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2022 - ] 

Result: 

OK 

See step  6

HINT: 

When the auxiliary battery voltage is low, the inverter water pump assembly may not operate.

Pre-procedure1

• None.

• According to the display on the GTS, perform the Active Test "Activate the Inverter Water Pump" and check the value of the Data List item "Inverter Water Pump Revolution".

  Powertrain > Hybrid Control > Active Test 

  Active Test Display
  Activate the Inverter Water Pump

  Data List Display
  Inverter Water Pump Revolution

  OK

  Tester Display	Condition	Specified Condition
  Inverter Water Pump Revolution	Ignition switch ON During Active Test	3000 to 9500 rpm

  HINT: 

  • Perform the Active Test with the inverter coolant temperature between -15 and 65°C (5 to 149°F).
  • When the inverter water pump assembly is not operating, the Data List item "Inverter Water Pump Revolution" displays a value 200 rpm or less.

  Result

  Result	Proceed to
  The value of Inverter Water Pump Revolution is between 3000 and 9500 rpm	A
  None of the above conditions are met	B

Post-procedure1

• Turn the ignition switch off.

Result: 

B 

See step  9

Result: 

A 

See step  7

Pre-procedure1

• Turn the ignition switch to ON (READY) and wait for 1 minute with the engine stopped.

• Enter the following menus: Powertrain / Hybrid Control / Data List / Generator Inverter Temperature, Motor Inverter Temperature, Rear Motor Inverter Temperature, Boosting Converter Temperature (Upper), Boosting Converter Temperature (Lower) and Inverter Coolant Water Temperature.

  Powertrain > Hybrid Control > Data List 

  Tester Display
  Generator Inverter Temperature
  Motor Inverter Temperature
  Rear Motor Inverter Temperature
  Boosting Converter Temperature (Upper)
  Boosting Converter Temperature (Lower)
  Inverter Coolant Water Temperature

• Read the Data List with the engine stopped.

  Result

  Result	Proceed to
  Other than below.	A
  "Inverter Coolant Water Temperature" value is higher than the displayed temperature of any other Data List item by 20°C (68°F) or more.	B

  HINT: 

  The lower limit temperature that can be displayed for "Generator Inverter Temperature", "Motor Inverter Temperature", "Boosting Converter Temperature (Upper)" and "Boosting Converter Temperature (Lower)" is 0°C (32°F). The lower limit temperature for "Inverter Coolant Water Temperature" is -40°C (-40°F). The "Inverter Coolant Water Temperature" value displayed on the GTS may be lower than the others, but this is not a malfunction.

Post-procedure1

• Turn the ignition switch off.

Result: 

B 

REPLACE HYBRID MOTOR CONTROL INVERTER ASSEMBLY. Refer to  REMOVAL [10/2022 - ] 

Result: 

A 

See step  8

Pre-procedure1

• Read the freeze frame data item "Ambient Temperature" using the GTS.

  Powertrain > Hybrid Control > Trouble Codes 

• Check if the freeze frame data item "Ambient Temperature" is below the freezing temperature of the HV coolant.

  Result

  Result	Proceed to
  Ambient Temperature value is above freezing temperature of the HV coolant.	A
  Ambient Temperature value is below freezing temperature of the HV coolant.	B

  HINT: 

  • HV coolant (SLLC) with a 30% concentration freezes at -15°C (5°F) and HV coolant (SLLC) with a 50% concentration freezes at -35°C (-31°F).
  • If the HV coolant freezes in the HV radiator or inverter water pump, the coolant temperature in the hybrid motor control inverter assembly rises because the HV coolant cannot circulate. As a result, a DTC may be stored.
  • A DTC is stored when the inverter water pump impeller cannot rotate due to freezing of the HV coolant.
  • If DTCs are output due to freezing of the LLC, the problem symptom cannot be reproduced. Check the LLC replacement history and whether the LLC was frozen based on the ambient temperature when the DTCs were stored.

Post-procedure1

• Turn the ignition switch off.

Result: 

A 

COOLING SYSTEM NORMAL (PERFORM NEXT STEP FOR REFERENCED DTC) 

Result: 

B 

REPLACE HV COOLANT. Refer to  REPLACEMENT [10/2022 - ] 

Refer to PROCEDURE - Step 1

Result

Result: 

NG 

CONNECT SECURELY 

Result: 

OK 

See step  10

1. Check the connector connections and contact pressure of the relevant terminals for the inverter water pump assembly connector.

   HINT: 

   Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [10/2022 - ]

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK

   The connector is connected securely, the terminals are not deformed or corroded and there are no contact problems.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

CONNECT SECURELY 

Result: 

OK 

See step  11

Pre-procedure1

• Disconnect the hybrid vehicle control ECU connector.
• Disconnect the inverter water pump assembly connector.

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

  Standard Resistance (Check for Open)

  Tester Connection	Condition	Specified Condition	Result
  A21-32 (IWP) - A42-3 (SWP)	Ignition switch off	Below 1 Ω	Ω

  Standard Resistance (Check for Short)

  Tester Connection	Condition	Specified Condition	Result
  A21-32 (IWP) or A42-3 (SWP) - Body ground and other terminals	Ignition switch off	10 kΩ or higher	kΩ

  Result

  Proceed to
  OK
  NG

Post-procedure1

• Reconnect the hybrid vehicle control ECU connector.
• Reconnect the inverter water pump assembly connector.

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  12

HINT: 

When the auxiliary battery voltage is low, the inverter water pump assembly may not operate.

Pre-procedure1

• Remove the INV W/PMP NO. 2 fuse from No. 1 engine room relay block and No. 1 junction block assembly.

• According to the display on the GTS, read the Data List.

  Powertrain > Hybrid Control > Data List 

  Tester Display
  Inverter Water Pump Revolution

  OK

  Tester Display	Condition	Specified Condition
  Inverter Water Pump Revolution	Ignition switch ON	200 rpm or less

  Result

  Result	Proceed to
  The value of Inverter Water Pump Revolution is 200 rpm or less	A
  None of the above conditions are met	B

Post-procedure1

• Turn the ignition switch off.
• Install the INV W/PMP NO. 2 fuse.

Result: 

B 

REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY. Refer to  REMOVAL [10/2022 - ] 

Result: 

A 

See step  13

Pre-procedure1

• Disconnect the hybrid vehicle control ECU connector.

• Measure the voltage according to the value(s) in the table below.

  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

  *a

  Component with harness connected (Hybrid Vehicle Control ECU)

  *b

  Front view of wire harness connector (to Hybrid Vehicle Control ECU)

  Standard Voltage

  Tester Connection	Condition	Specified Condition	Result
  A21-32 (IWP) - C59-1 (E1)	INV W/P relay holder terminals 3 and 5 connected Ignition switch off	11 to 14 V	V

  NOTE:

  Make sure to check for and clear DTCs after performing this inspection.

  Result

  Proceed to
  OK
  NG

Post-procedure1

• Turn the ignition switch to off.
• Reconnect the hybrid vehicle control ECU connector.

Result: 

NG 

See step  15

Result: 

OK 

See step  14

Pre-procedure1

• Connect an oscilloscope between the hybrid vehicle control ECU terminals specified in the table below.

• Check the waveform while turning the ignition switch to ON.

  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

  *a

  Component with harness connected (Hybrid Vehicle Control ECU)

  -

  -

  Item	Content
  Terminal	A21-32 (IWP) - C59-1 (E1)
  Equipment Setting	5 V/DIV., 50 ms./DIV.
  Condition	Ignition switch ON

  OK

  Waveform duty ratio is between 3% and 9%.

  Result

  Proceed to
  OK
  NG

Post-procedure1

• Turn the ignition switch off.

Result: 

NG 

REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY. Refer to  REMOVAL [10/2022 - ] 

Result: 

OK 

See step  15

HINT: 

Refer to REMOVAL [10/2022 - ]

Result

Result: 

NEXT 

See step  16

1. After replacing the inverter water pump assembly, add HV coolant and perform air bleeding.

   HINT: 

   Refer to REPLACEMENT [10/2022 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

END