Cooling System [09/2023 - ]: 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 intercooler reserve tank assembly is above the low line.	A
   No leaks are found and the HV coolant level in the intercooler 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 "Control the Intercooler Water Pump" (Engine Control System) and "Control the Engine 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 does not operate	A
  Cooling fan does not stop
  Cooling fan operates	B

Post-procedure1

• Turn the ignition switch off.

Result: 

A 

CHECK COOLING FAN SYSTEM. Refer to  Cooling Fan Circuit [09/2023 - ] 

Result: 

B 

See step  5

HINT: 

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

Pre-procedure1

• None

• Read the Data List during 85% drive of the inverter water pump assembly (with motor).

  Powertrain > Engine > Active Test 

  Active Test Display
  Control the Intercooler Water Pump

  Data List Display
  Intercooler Water Pump Speed

  Result

  GTS Operation	Intercooler Water Pump Speed
  85%	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 (with motor) is not operating, the Data List item "Intercooler Water Pump Speed" displays a value 200 rpm or less.

  Result

  Proceed to
  OK
  NG

Post-procedure1

• Turn the ignition switch off.

Result: 

NG 

See step  8

Result: 

OK 

See step  6

Pre-procedure1

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

• Read the Data List with the engine stopped.

  Powertrain > Hybrid Control > Data List 

  Tester Display
  Motor Inverter Temperature
  Rear Motor Inverter Temperature
  Inverter Coolant Water Temperature

  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 "Motor Inverter Temperature, Rear Motor Inverter Temperature" 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 [09/2023 - ] 

Result: 

A 

See step  7

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 radiator or water pump, the coolant temperature in the inverter 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 [09/2023 - ] 

1. Check the connector connections and contact pressure of the relevant terminals for the ECM connectors.

   HINT: 

   Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [09/2023 - ]

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK

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

   Result

   Proceed to
   OK
   NG

Result: 

NG 

CONNECT SECURELY 

Result: 

OK 

See step  9

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

   HINT: 

   Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [09/2023 - ]

   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  10

Pre-procedure1

• Disconnect the ECM connector.
• Disconnect the inverter water pump assembly (with motor) connector.

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

  Standard Resistance (Check for Open)

  Tester Connection	Condition	Specified Condition	Result
  C26-45 (IWPO) - C33-3 (SWP)	Ignition switch off	Below 1 Ω	Ω

  Standard Resistance (Check for Short)

  Tester Connection	Condition	Specified Condition	Result
  C26-45 (IWPO) or C33-3 (SWP) - Body ground and other terminals	Ignition switch off	10 kΩ or higher	kΩ

  Result

  Proceed to
  OK
  NG

Post-procedure1

• Reconnect the inverter water pump assembly (with motor) connector.
• Reconnect the ECM connector.

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  11

HINT: 

When the auxiliary battery voltage is low, the inverter water pump 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.
• Turn the ignition switch to ON.

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

  Powertrain > Engine > Data List 

  Tester Display
  Intercooler Water Pump Speed

  Result

  Result	Proceed to
  The value of Intercooler Water Pump Speed 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 ECM. Refer to  REMOVAL [09/2023 - ] 

Result: 

A 

See step  12

Pre-procedure1

• Disconnect the ECM connector.
• Turn the ignition switch to ON.

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

  Standard Voltage

  Tester Connection	Condition	Specified Condition	Result
  C26-45 (IWPO) - Body ground	Ignition switch ON	11 to 14 V	V

  NOTE:

  If the ignition switch is turned to ON with the ECM connectors disconnected, other DTCs will be stored. Be sure to clear the DTCs after the inspection.

  Result

  Proceed to
  OK
  NG

Post-procedure1

• Turn the ignition switch off.
• Reconnect the ECM connector.

Result: 

NG 

See step  14

Result: 

OK 

See step  13

Pre-procedure1

• Disconnect the inverter water pump assembly (with motor) connector.

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

  Powertrain > Engine > Active Test 

  Tester Display
  Control the Intercooler Water Pump

  Standard Resistance

  Tester Connection	Condition	Specified Condition
  C33-3 (SWP) - Body ground	Active Test OFF → ON	Active Test OFF: Resistance stabilized → ON: Resistance changes*

  HINT: 

  *: The transistor inside the ECM performs duty control according to the Active Test being operated. The resistance of the IWPO terminal changes while the Active Test is on due to duty control. If the resistance is stable while the Active Test is off and changes while the Active Test is on, the transistor is working correctly. If the transistor does not operate when the Active Test is on, there may be a malfunction in the ECM.

  Result

  Proceed to
  OK
  NG

Post-procedure1

• Reconnect the inverter water pump assembly (with motor) connector.

Result: 

NG 

REPLACE ECM. Refer to  REMOVAL [09/2023 - ] 

Result: 

OK 

See step  14

HINT: 

Refer to REMOVAL [09/2023 - ]

Result

Result: 

NEXT 

See step  15

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

   HINT: 

   Refer to REPLACEMENT [09/2023 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

END