Replacement [07/2020 - 12/2021]: Procedure

DRAIN COOLANT (for Inverter)

WARNING:

To avoid the danger of being burned, do not remove the reserve tank cap while the coolant (for inverter) is still hot. Pressurized, hot coolant (for inverter) and steam may be released and cause serious burns.

NOTE:

Do not reuse the drained coolant because it may contain foreign matter.
Collect the drained coolant and measure its volume to establish a benchmark. When adding coolant, make sure to add more coolant than the measured amount.

Remove the reserve tank cap from the inverter reserve tank assembly.

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

Loosen the drain cock plug indicated in the illustration and drain the coolant.
WARNING:
To avoid the danger of being burned, do not loosen the drain cock plug while the coolant (for inverter) is still hot. Pressurized, hot coolant (for inverter) and steam may be released and cause serious burns.
Tighten the drain cock plug by hand.
Disconnect the hose from the drain cock.

ADD COOLANT (for Inverter)

NOTE:

Do not reuse the drained coolant because it may contain foreign matter.

If the vehicle is driven with air in the inverter cooling system, damage may occur and the following DTCs may be stored.

DTC No.	Detection Item
P0A9300	Inverter "A" Cooling System Performance
P0A001C	Motor Electronics Coolant Temperature Sensor Circuit Voltage Out of Range
P0A789E	Drive Motor "A" Inverter Stuck On
P1C5D19	Drive Motor "A" Inverter Circuit Current Above Threshold
P0A7A9E	Generator Inverter Stuck On
P1C5F19	Generator Inverter Circuit Current Above Threshold
P0A949E	DC/DC Converter Stuck On
P0D3319	DC/DC Converter Circuit Current Above Threshold
P0AED1C	Drive Motor Inverter Temperature Sensor "A" Circuit Voltage Out of Range
P0C381C	DC/DC Converter Temperature Sensor "A" Circuit Voltage Out of Range
P0C3D1C	DC/DC Converter Temperature Sensor "B" Circuit Voltage Out of Range
P1CCC96	DC/DC Converter Enable Component Internal Failure

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

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Standard Capacity

2.0 liters (2.1 US qts, 1.8 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.

When using the GTS:

Activate the Inverter Water Pump

Powertrain > Hybrid Control > Active Test

Tester Display
Activate the Inverter Water Pump

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 with motor assembly at 1 minute intervals.
Standard

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

HINT:

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

When not using the GTS:
1. Turn the ignition switch to ON (READY). [*1]
2. Turn the ignition switch off and add coolant to the FULL line as the coolant level will drop as the air bleeds. [*2]
  NOTE:
  - Be sure to turn the ignition switch off before adding SLLC.
  - Do not work on the components in the engine compartment while the ignition switch is ON (READY) as the engine will operate intermittently.
3. Repeat steps [*1] and [*2] until air bleeding from the cooling system is completed.
  Standard
  
  Air bleeding from the inverter cooling system is completed when the noise made by the inverter water pump with motor assembly becomes smaller and the circulation of coolant in the inverter reserve tank assembly improves.
  
  HINT:
  
  Loud noises made by the inverter water pump with motor assembly and poor circulation of coolant in the inverter reserve tank assembly indicate that there is air in the cooling system.

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

INSPECT FOR COOLANT LEAK (for Inverter)
Refer to PROCEDURE - Step 1