Toyota Avalon (XX50) 2019-2022 Service & Repair Manual: Problem Symptoms Table

PROBLEM SYMPTOMS TABLE

NOTICE:

If the auxiliary battery voltage becomes low, auxiliary battery load control will operate in order to ensure sufficient power is supplied to the power steering system. In this case, the seat heater system (for HV model) may not operate.

HINT:

Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.
Inspect the fuses and relays related to this system before inspecting the suspected areas below.

Seat Heater System

Symptom	Suspected Area	Link
Front seat heater does not operate for driver side and front passenger side seat	Seat heater switch (radio and display receiver assembly)	-
	Air conditioning amplifier assembly	-
	S/HTR F/R relay	-
	Wire harness or connector	-
Seat heater for front right seat does not operate	Refer to the "Seat Heater for Front Right Seat does not Operate".
Seat heater for front left seat does not operate	Refer to the "Seat Heater for Front Left Seat does not Operate".
Seat heater for rear left and rear right seat do not operate	Air conditioning amplifier assembly	-
Seat heater for rear right seat does not operate	Seat heater assembly (rear seat cushion heater RH)
	Seat heater assembly (rear seatback heater RH)
	Seat heater switch (RH)
	S/HTR R/R relay	-
	Wire harness or connector	-
	Air conditioning amplifier assembly	-
Seat heater for rear left seat does not operate	Seat heater assembly (rear seat cushion heater LH)
	Seat heater assembly (rear seatback heater LH)
	Seat heater switch (LH)
	S/HTR R/L relay	-
	Wire harness or connector	-
	Air conditioning amplifier assembly	-

Toyota Avalon (XX50) 2019-2022 Service & Repair Manual > Lighting System(for Gasoline Model): Interior Light Circuit
DESCRIPTION The main body ECU (multiplex network body ECU) controls the operation of the following lights: Map Light (Roof Console Box Sub-assembly) Spot Light Assembly WIRING DIAGRAM CAUTION / NOTICE / HINT NOTICE: Inspect the fuses for circuits related to this system before performing the followin ...

Toyota Avalon (XX50) 2019-2022 Owners Manual