Cooling System [11/2021 - 03/2023]: 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 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 inverter with converter 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

1. 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

2. Turn the ignition switch off.

Result: 

B 

CHECK COOLING FAN SYSTEM. Refer to  Cooling Fan Circuit [11/2021 - ] 

Result: 

A 

See step  5

HINT: 

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

1. 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	3176 to 8617 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.
2. Turn the ignition switch off.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  8

Result: 

OK 

See step  6

1. Turn the ignition switch to ON (READY) and wait for 1 minute with the engine stopped.
2. Read the Data List with the engine stopped.

   Powertrain > Hybrid Control > Data List 

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

   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.

3. Turn the ignition switch off.

Result: 

B 

REPLACE INVERTER WITH CONVERTER ASSEMBLY. Refer to  REMOVAL [11/2021 - ] 

Result: 

A 

See step  7

1. Read the Freeze Frame Data item "Ambient Temperature" using the GTS.

   Powertrain > Hybrid Control > Trouble Codes 

2. 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 inverter with converter 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.
3. Turn the ignition switch off.

Result: 

A 

COOLING SYSTEM NORMAL (PERFORM NEXT STEP FOR REFERENCED DTC) 

Result: 

B 

REPLACE HV COOLANT. Refer to  REPLACEMENT [11/2021 - 03/2024] 

Refer to PROCEDURE - Step 1

Result

Result: 

NG 

CONNECT SECURELY 

Result: 

OK 

See step  9

1. Check the connector connections and contact pressure of the relevant terminals for the A56 inverter water pump assembly connector.

   Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [11/2021 - ]

   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

1. Disconnect the hybrid vehicle control ECU connector.
2. Disconnect the inverter water pump assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance (Check for Open)

   Tester Connection	Condition	Specified Condition
   A27-31 (IWP) - A48-3 (SWP)	Ignition switch off	Below 1 Ω

   Standard Resistance (Check for Short)

   Tester Connection	Condition	Specified Condition
   A27-31 (IWP) or A48-3 (SWP) - Body ground and other terminals	Ignition switch off	10 kΩ or higher

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Hybrid Vehicle Control ECU)
   *b	Front view of wire harness connector (to Inverter Water Pump Assembly)

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

   Result

   Proceed to
   OK
   NG

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 assembly may not operate.

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

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

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE HYBRID VEHICLE CONTROL ECU. Refer to  REMOVAL [11/2021 - ] 

Result: 

OK 

See step  12

1. Disconnect the hybrid vehicle control ECU connector.
2. Turn the ignition switch to ON.
3. 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
   A27-31 (IWP) - D67-15 (E1)	Ignition switch ON	11 to 14 V

   NOTE:

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

4. Turn the ignition switch off.
5. Reconnect the hybrid vehicle control ECU connector.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  14

Result: 

OK 

See step  13

1. Connect an oscilloscope between the hybrid vehicle control ECU terminals specified in the table below.
2. Turn the ignition switch to ON.
3. 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	A27-31 (IWP) - D67-15 (E1)
   Equipment Setting	5 V/DIV., 50 ms./DIV.
   Condition	Ignition switch ON

   OK

   Waveform duty ratio is between 3% and 9%.

4. Turn the ignition switch off.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE HYBRID VEHICLE CONTROL ECU. Refer to  REMOVAL [11/2021 - ] 

Result: 

OK 

See step  14

Refer to REMOVAL [11/2021 - 03/2024]

Result

Result: 

NEXT 

See step  15

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

   Refer to REPLACEMENT [11/2021 - 03/2024]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

END