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

Toyota Avalon (XX50) 2019-2022 Service & Repair Manual / Vehicle Interior / Heating / Air Conditioning / Air Conditioning System(for Gasoline Model) / Problem Symptoms Table

PROBLEM SYMPTOMS TABLE

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.

VEHICLE CHECK ITEMS

HINT:

You can reduce the number of systems to check by using the results of the following operation check
Perform the following checks based on Customer Feedback and the vehicle condition.
The customer's opinion may not be consistent with the actual problem (eg: the cooling performance of the air conditioner is bad → actually, the wind volume is weak). It is important to check the problem symptoms accurately and judge correctly based on various sources of information.
Judgment as to whether the air conditioner panel is normal or abnormal can be judged by checking if the indicator illuminates or turns off when the switch is operated.
During servo motor initialization, the AUTO indicator light comes on, and then goes off when initialization has finished.
If the performance of the air conditioner is poor or there is a foul odor, check for clogging in the clean air filter.

Malfunction Operation/Function:

Common Function of Cool and Heater Function				Only Cool Air Function	Only Heater Function	Suspected Area
A/C Switch Operation	Blower Operation	Recirculation/Fresh Function	Air Outlet Changing Function	Only Cool Air Function	Only Heater Function	Suspected Area
x	o	o	o	x	x	Go to "Problem Symptoms Table: Air Conditioning Control"
o	o	o	o	x	o	Go to "Problem Symptoms Table: Cooling Function"
o	o	o	o	o	x	Go to "Problem Symptoms Table: Heater Function"
o	x	o	o	x	x	Go to "Problem Symptoms Table: Blower Control"
o	o	x	o	x	x	Go to "Problem Symptoms Table: Air Inlet Control"
o	o	o	x	x	x	Go to "Problem Symptoms Table: Air Outlet Control"
x	x	x	x	x	x	Air Conditioning Amplifier Assembly or Air Conditioning Assembly is Defective

AIR CONDITIONING CONTROL

Symptom	Suspected Area	Link
Air conditioning system cannot be operated using air conditioning control panel (radio and display receiver assembly) (With the exception of the switch indicators, no inputs are reflected when other switches operated)	Air conditioning amplifier assembly Air conditioning control panel (radio and display receiver assembly)
Air conditioning system cannot be operated using air conditioning control panel (radio and display receiver assembly) (Air conditioning system display operates)	Air conditioning control panel (radio and display receiver assembly)
Air conditioning system cannot be operated using air conditioning control panel (radio and display receiver assembly) immediately after starting the engine (Air conditioning system display operates) (Only AUTO indicator illuminates) (A/C switch indicator does not illuminate)	Refer to "INITIALIZATION"
A/C switch indicator does not illuminate	Air conditioning amplifier assembly Air conditioning control panel (radio and display receiver assembly) A/C switch A/C switch indicator Servo motor Damper and damper link Refrigerant pressure Ambient temperature

COOLING FUNCTION

Symptom	Suspected Area	Link
No cool air comes out (Blower control is normal)	Cooler compressor assembly Refrigerant pressure Refrigerant volume Cooler condenser assembly Cooling fan system Damper and damper link No. 1 cooler thermistor High inlet air temperature
Cooling effectiveness is poor Cooling response is slow	ECO switch assembly (electric parking brake switch assembly) Cooler compressor assembly Refrigerant volume Cooler condenser assembly Cooling fan system Damper and damper link Automatic light control sensor High inlet air temperature Harness or connector
Temperature of outlet air is cooler on left or right side (when same temperature set for both sides)	Cooler compressor assembly Refrigerant volume Damper and damper link Automatic light control sensor Harness or connector
Compressor assembly with pulley does not stop operating Refrigerant pressure does not decrease when A/C switch is turned off	Short to +B in air conditioning amplifier assembly circuit MG CLT relay Magnet clutch assembly

HEATER FUNCTION

Symptom

Suspected Area

Link

No warm air comes out
(Blower control is normal)
Outlet air temperature does not increase
(Blower control is normal)

Engine coolant temperature
Refrigerant volume
No. 1 air conditioning radiator damper servo sub-assembly
Damper and damper link
Warm-up control
Blockage in heater radiator unit sub-assembly
Heater radiator unit sub-assembly

Temperature of outlet air is warmer on left or right side

(when same temperature set for both sides)

Damper and damper link
Blockage in heater radiator unit sub-assembly
Harness or connector

BLOWER CONTROL

Symptom

Suspected Area

Link

Blower motor does not operate at all

(Air does not blow from registers)

Blower motor with fan sub-assembly
Air conditioning amplifier assembly
Warm-up control
Engine coolant temperature sensor
Harness or connector

Airflow volume cannot be changed

Air conditioning amplifier assembly
Blower motor with fan sub-assembly
Harness or connector

Airflow volume is constantly low
Airflow volume sometimes becomes low

Blower motor with fan sub-assembly
ECO switch assembly (electric parking brake switch assembly)
Clean air filter
No. 1 cooler evaporator sub-assembly or heater radiator unit sub-assembly fins
No. 1 cooler thermistor
Aspirator

AIR INLET CONTROL

Symptom	Suspected Area	Link
Air inlet mode changes between recirculation/fresh randomly Recirculation/fresh switch indicator is blinking	Customize setting* Ambient temperature Refrigerant pressure Air conditioner pressure sensor circuit Engine coolant temperature
Air inlet mode cannot be changed between recirculation/fresh Air inlet mode does not change between recirculation/fresh automatically	No. 1 blower damper servo sub-assembly Damper link Air inlet damper mechanically locked Engine coolant temperature Air conditioner unit assembly

*: except USA and Canada

AIR OUTLET CONTROL

Symptom

Suspected Area

Link

Air outlet mode cannot be changed

(air outlet display changes)

No. 1 air conditioning radiator damper servo sub-assembly
Damper link
Air conditioner unit assembly

Air outlet mode cannot be changed

(air outlet display does not change)

Air conditioning control panel (radio and display receiver assembly)

DEFROSTER CONTROL

Symptom	Suspected Area	Link
Windshield frequently fogs up	Cooler compressor assembly Refrigerant volume Cooler expansion valve No. 1 air conditioning radiator damper servo sub-assembly Damper and damper link

Precaution

Recirculated/Fresh Air Modes do not Switch

See More:

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

Precaution

Recirculated/Fresh Air Modes do not Switch

See More:

Toyota Avalon (XX50) 2019-2022 Owners Manual

Toyota Avalon (XX50) 2019-2022 Service & Repair Manual