Replacement [02/2024 - ]: Procedure

1. Remove the inverter reserve tank cap from the inverter reserve tank assembly.
2. Remove the front bumper guard base cover.

   Refer to PROCEDURE - Step 5

3. Remove the No. 1 engine under cover sub-assembly.

   Refer to PROCEDURE - Step 6

4. Connect a hose with an inside diameter of 9 mm (0.354 in.) to the drain cock as shown in the illustration.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *1	Drain Cock Plug
   *2	Hose

5. Loosen the drain cock plug and drain the coolant.
6. Tighten the drain cock plug.
7. Disconnect the hose from the radiator drain cock.
8. Install the No. 1 engine under cover sub-assembly.

   Refer to PROCEDURE - Step 48

9. Install the front bumper guard base cover.

   Refer to PROCEDURE - Step 49

1. Slowly pour coolant into the inverter reserve tank assembly until it reaches the FULL line.

   Standard Capacity

   2.4 liters (2.5 US qts, 2.1 Imp. qts)

   NOTE:

   To prevent foreign matter such as dust or dirt from entering the cooling system, make sure to confirm that the container used to add coolant is clean and free of foreign matter.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. Activate the Inverter Water Pump.

   Powertrain > Hybrid Control > Active Test 

   Tester Display
   Activate the Inverter Water Pump

   HINT: 

   The inverter water pump with motor assembly can also be operated using inspection mode.

   See step  3

3. While adding coolant to the inverter reserve tank assembly to keep the coolant at the FULL line and compensate for the drop in the coolant level as the air bleeds, operate and stop the inverter water pump assembly at 1 minute intervals.

   Standard

   Air bleeding from the inverter cooling system is completed when the noise made by the inverter water pump assembly becomes smaller and the circulation of coolant in the inverter reserve tank assembly improves.

   HINT: 

   Loud noises made by the inverter water pump assembly and poor circulation of coolant in the inverter reserve tank assembly indicate that there is air in the cooling system.

4. After the air is completely bled from the inverter cooling system, add coolant to the Full line of inverter reserve tank assembly and install the reserve tank cap.
   NOTE:

   Make sure that more coolant than the volume collected coolant volume is added.

1. Slowly pour coolant into the inverter reserve tank assembly until it reaches the FULL line.

   Standard Capacity

   2.4 liters (2.5 US qts, 2.1 Imp. qts)

   NOTE:

   To prevent foreign matter such as dust or dirt from entering the cooling system, make sure to confirm that the container used to add coolant is clean and free of foreign matter.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. Operation for entering Inspection Mode:
   1. If using the GTS, turn the ignition switch to ON and perform the following operations.

      Powertrain > Hybrid Control > Utility 

      Tester Display
      Inspection Mode

      1. Enter the following menus: Powertrain / Hybrid Control / Utility / Inspection Mode
      2. Select "4WD/AWD MAINTENANCE MODE (4WD for measuring Exhaust Gas)" according to the screen display and press "Next". (*1)
         NOTE:

         • Proceeding to step 2 (*1) will enter Inspection Mode and cause the inverter water pump with motor assembly to operate.
         • Because turning the ignition switch to ON (READY) will decrease the W/P rotation speed and prevent adequate air bleeding, perform replacement without turning the ignition switch to ON (READY).
         • After entering Inspection Mode, the inverter water pump with motor assembly will continue operating until Inspection Mode is canceled.
   2. If not using the GTS, turn the ignition switch to ON and perform the following operations within 60 seconds.
      1. With the shift position in P, fully depress the accelerator pedal 4 times.
      2. With the brake pedal depressed with your left foot, change the shift position to N and fully depress the accelerator pedal 4 times.
      3. Change the shift position to P and fully depress the accelerator pedal 4 times. (*2)
         NOTE:

         • Depressing the accelerator pedal from the fully released position to the fully depressed position counts as 1 time.
         • Proceeding to step 3 (*2) will enter Inspection Mode and cause the inverter water pump with motor assembly to operate.
         • Because turning the ignition switch to ON (READY) will decrease the W/P rotation speed and prevent adequate air bleeding, perform replacement without turning the ignition switch to ON (READY).
         • After entering Inspection Mode, the inverter water pump with motor assembly will continue operating until Inspection Mode is canceled.
3. Operation for canceling Inspection Mode:
   1. Turn the ignition switch off.
      NOTE:

      • Inspection Mode is not canceled simply by selecting "End" in the GTS. Be sure to turn the ignition switch off.
      • After canceling Inspection Mode, turn the ignition switch to ON again, and check that the display on the multi-information display when entering Inspection Mode has gone out.
4. While adding coolant to the inverter reserve tank assembly to keep the coolant at the FULL line and compensate for the drop in the coolant level as the air bleeds, operate and stop the inverter water pump assembly at 1 minute intervals.

   Standard

   Air bleeding from the inverter cooling system is completed when the noise made by the inverter water pump assembly becomes smaller and the circulation of coolant in the inverter reserve tank assembly improves.

   HINT: 

   Loud noises made by the inverter water pump assembly and poor circulation of coolant in the inverter reserve tank assembly indicate that there is air in the cooling system.

5. After the air is completely bled from the inverter cooling system, add coolant to the Full line of inverter reserve tank assembly and install the reserve tank cap.
   NOTE:

   Make sure that more coolant than the volume collected coolant volume is added.

Refer to PROCEDURE - Step 1