Problem Symptoms Table [10/2020 - 07/2022]
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2024 Lexus UX 250h, 2023 Lexus UX 250h, 2022 Lexus UX 250h, 2021 Lexus UX 250h, and 2020 Lexus UX 250h. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
- 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 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
Refer to Operation not Accepted Even If Air Conditioning Switch is Operated [10/2018 - ] Air conditioning system cannot be operated using air conditioning control assembly - (Air conditioning system display operates)
Air conditioning control assembly Refer to REMOVAL [10/2018 - 07/2022] 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" Refer to INITIALIZATION [10/2018 - ] 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
Refer to A/C Switch Indicator does not Turn On [10/2018 - 07/2022] - 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
Refer to No Cool Air Comes Out [10/2018 - 07/2022] - Cooling effectiveness is poor
- Cooling response is slow
- ECO switch (satellite switch set)
- 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
Refer to Cooling is Poor [10/2018 - 07/2022] Temperature of outlet air is cooler on left or right side - (When same temperature set for both sides)
- Compressor with motor assembly
- Refrigerant volume
- Damper and damper link
- Automatic light control sensor
- Harness or connector
Refer to Air Vent Temperature does not Change and Right Vent is Different from Left and Vice Versa (Same Left/Right Temperature Setting) [10/2018 - 07/2022] - 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
- Flow shutting valve (water by-pass hose assembly)
Refer to No Warm Air Comes Out [10/2018 - ] 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
Refer to Air Vent Temperature does not Change and Right Vent is Different from Left and Vice Versa (Same Left/Right Temperature Setting) [10/2018 - 07/2022] - No warm air comes out
- 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
Refer to Blower Motor does not Operate [10/2018 - ] Airflow volume cannot be changed - Air conditioning amplifier assembly
- Blower motor with fan sub-assembly
- Harness or connector
Refer to Blower Motor Circuit [10/2018 - ] - Airflow volume is constantly low
- Airflow volume sometimes becomes low
- Blower motor with fan sub-assembly
- ECO switch (satellite switch set)
- Clean air filter
- No. 1 cooler evaporator sub-assembly or heater radiator unit sub-assembly fins
- No. 1 cooler thermistor
- Aspirator pipe
Refer to Weak Blower Output [10/2018 - ] - 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
Refer to Recirculated/Fresh Air Modes Switch without User Input [10/2018 - 07/2022] - Air inlet mode cannot be changed between recirculation/fresh
- Air inlet mode does not change between recirculation/fresh automatically
- Exhaust gas odor when set to recirculation
- No. 1 blower damper servo sub-assembly
- Damper link
- Air inlet damper mechanically locked
- Air conditioner unit assembly
- Engine coolant temperature
Refer to Recirculated/Fresh Air Modes do not Switch [10/2018 - ] - *: w/o Satellite Radio
- 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
Refer to Air Vent cannot be Switched [10/2020 - ] Air outlet mode cannot be changed - (Air outlet display does not change)
Air conditioning control assembly Refer to REMOVAL [10/2018 - 07/2022] - 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
Refer to Front Window Fogging [10/2018 - 07/2022]