HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): PROBLEM SYMPTOMS TABLE; 2023 - 2025 MY Corolla Corolla HV [09/2022

Last Modified: 07-31-2024	6.11:8.1.0	Doc ID: RM1000000025THA
Model Year Start: 2023	Model: Corolla	Prod Date Range: [09/2022 - ]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): PROBLEM SYMPTOMS TABLE; 2023 - 2025 MY Corolla Corolla HV [09/2022 - ]

PROBLEM SYMPTOMS TABLE

NOTICE:

Perform the inspection when the vehicle is at ambient temperature. If this is not done, there could be a risk of injury depending on the location being inspected.
Inspect the fuses and relays related to this system before inspecting the suspected areas below.
The air conditioning system uses the CAN communication system. First, confirm that there is no malfunction in the CAN communication system. Refer to the How to Proceed with Troubleshooting procedure.
Click here

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 turns 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 Conditioner Unit 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)	LIN communication line (air conditioning amplifier assembly - air conditioning control assembly) +B or ground in air conditioning amplifier assembly circuit 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 hybrid system (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 Servo motor Damper and damper link Refrigerant pressure Ambient temperature

COOLING FUNCTION

Symptom	Suspected Area	Link
Cool air is not discharged (Air is discharged)	Compressor with motor assembly Refrigerant pressure Refrigerant volume Cooler condenser assembly Cooling fan system Damper and damper link Evaporator temperature sensor
Cooling effectiveness is poor Cooling response is slow	Drive mode select switch (combination switch assembly) Compressor with motor assembly Refrigerant volume Cooler condenser assembly Cooling fan system Damper and damper link Solar sensor (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 Refrigerant volume Damper and damper link Warm-up control Heater radiator unit sub-assembly
Heating performance is poor when it is cold*	PTC heater (quick heater assembly) Air conditioning amplifier assembly Harness or connector

BLOWER CONTROL

Symptom	Suspected Area	Link
No air flows from the 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	Drive mode select switch (combination switch assembly) Blower motor with fan sub-assembly Air conditioning amplifier assembly Clean air filter Evaporator or heater radiator fins Evaporator temp. sensor Aspirator pipe not connected properly Harness or connector

AIR INLET CONTROL

Symptom	Suspected Area	Link
Recirculation/fresh mode changes without permission Recirculation/fresh mode light blinks	Customize setting Ambient temperature Refrigerant pressure Air conditioning pressure sensor circuit Engine coolant temperature
Air inlet mode cannot be changed between recirculation/fresh Exhaust gas odors can be smelled when air inlet mode set to recirculation mode	Servo motor Damper and damper link Engine coolant temperature Air conditioner unit assembly

AIR OUTLET CONTROL

Symptom	Suspected Area	Link
Air outlet mode cannot be changed (Air outlet display changes)	Servo motor 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 Servo motor Damper and damper link Cooler expansion valve Mechanical locking of damper and damper link