HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): PROBLEM SYMPTOMS TABLE; 2020 - 2022 MY Corolla Corolla HV [01/2019

Last Modified: 07-31-2024	6.11:8.1.0	Doc ID: RM100000001H96Z
Model Year Start: 2020	Model: Corolla	Prod Date Range: [01/2019 - 09/2022]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): PROBLEM SYMPTOMS TABLE; 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022]

PROBLEM SYMPTOMS TABLE

NOTICE:

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 assembly (With the exception of the switch indicators, no inputs are reflected when other switches operated)	Air conditioning amplifier assembly Air conditioning control assembly Harness or connector
Air conditioning system cannot be operated using air conditioning control assembly (Air conditioning system display operates)	Air conditioning control assembly
Air conditioning system cannot be operated using air conditioning control 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 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)	Compressor with motor 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 (air conditioning control assembly) Compressor with motor assembly Refrigerant volume Cooler condenser assembly Cooling fan system Damper and damper link Automatic light control sensor High inlet air temperature Harness or connector

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 No. 1 air conditioning radiator damper servo sub-assembly Damper and damper link Warm-up control Blockage in heater radiator unit sub-assembly Quick heater assembly* Heater radiator unit sub-assembly
Heating performance is poor when it is cold*	Quick heater assembly Air conditioning amplifier assembly PTC HTR relay Harness or connector

BLOWER CONTROL

Symptom	Suspected Area	Link
Blower motor does not operate at all (Air does not blow from registers)	Air conditioning amplifier assembly Blower motor with fan sub-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 (air conditioning control assembly) Clean air filter No. 1 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 Air conditioner unit assembly Engine coolant temperature

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 No. 2 air conditioning radiator damper servo sub-assembly* No. 3 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 assembly

DEFROSTER CONTROL

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