Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001APSB
Model Year Start: 2019 Model: Avalon Prod Date Range: [04/2018 -           ]
Title: SEAT: SEAT HEATER SYSTEM (for Gasoline Model): OPERATION CHECK; 2019 - 2022 MY Avalon [04/2018 -        ]

OPERATION CHECK

CHECK FRONT SEAT HEATER

(a) Turn the engine switch on (IG).

(b) Turn the seat heater switch (radio and display receiver assembly) on and check that the indicator illuminates and the surface of the front seat warms up.

(c) Check that the front seat surface temperature changes according to the operation of the seat heater switch (radio and display receiver assembly) as follows: HI → MID → LO.

CHECK REAR SEAT HEATER (w/ Rear Seat Heater)

(a) Turn the engine switch on (IG).

(b) Turn the seat heater switch on and check that the indicator illuminates and the surface of the rear seat warms up.

CHECK THERMOSTAT OF SEAT HEATER ASSEMBLY (REAR SEAT CUSHION HEATER LH) (w/ Rear Seat Heater)

(a) Remove the seat heater assembly (rear seat cushion heater LH).

Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; SEAT: REAR SEAT CUSHION HEATER: REMOVAL

(b) Remove the seat heater assembly (rear seatback heater LH).

Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; SEAT: REAR SEATBACK HEATER: REMOVAL

(c) Connect the B seat heater assembly (rear seatback heater LH) connector and A seat heater assembly (rear seat cushion heater LH) connector.

*a

Component without harness connected

(Seat Heater Assembly (Rear Seat Cushion Heater LH))

*b

Component without harness connected

(Seat Heater Assembly (Rear Seatback Heater LH))

(d) Apply battery voltage and check the operation of the rear seat heater as shown in the table below.

NOTICE:

To prevent the rear seat heater from overheating, be sure to disconnect the battery from the rear seat heater immediately after this inspection is completed.

OK:

Battery Connection

Specified Condition

Battery positive (+) → Terminal K57-1

Rear seat heater operates (Temperature 36 to 44°C (96.8 to 111.2°F))

Battery negative (-) → Terminal K57-2

CHECK THERMOSTAT OF SEAT HEATER ASSEMBLY (REAR SEAT CUSHION HEATER RH) (w/ Rear Seat Heater)

(a) Remove the seat heater assembly (rear seat cushion heater RH).

Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; SEAT: REAR SEAT CUSHION HEATER: REMOVAL

(b) Remove the seat heater assembly (rear seatback heater RH).

Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; SEAT: REAR SEATBACK HEATER: REMOVAL

(c) Connect the C seat heater assembly (rear seat cushion heater RH) connector and D seat heater assembly (rear seatback heater RH) connector.

*a

Component without harness connected

(Seat Heater Assembly (Rear Seat Cushion Heater RH))

*b

Component without harness connected

(Seat Heater Assembly (Rear Seatback Heater RH))

(d) Apply battery voltage and check the operation of the rear seat heater as shown in the table below.

NOTICE:

To prevent the rear seat heater from overheating, be sure to disconnect the battery from the rear seat heater immediately after this inspection is completed.

OK:

Battery Connection

Specified Condition

Battery positive (+) → Terminal K58-1

Rear seat heater operates (Temperature 36 to 44°C (96.8 to 111.2°F))

Battery negative (-) → Terminal K58-2