Problem Symptoms Table
WARNING: This page is about a different car, the 2008 Lexus IS F. However, it is still accessible from the selected car via links, so may be relevant.
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.
Air Conditioning System
PROBLEM SYMPTOMS CHART
| Symptom | Suspected Area | See | ||||
|---|---|---|---|---|---|---|
| All functions of the A/C system do not operate | IG power source circuit | IG POWER SOURCE CIRCUIT | ||||
| Back-up power source circuit | BACK-UP POWER SOURCE CIRCUIT | |||||
| Integration control and panel assembly(1) | AIR CONDITIONING PANEL | |||||
| Multi-display(2) | REMOVAL | |||||
| A/C amplifier | AIR CONDITIONING AMPLIFIER | |||||
| Air Flow Control No blower operation | Blower motor circuit | BLOWER MOTOR CIRCUIT | ||||
| Integration control and panel assembly(1) | AIR CONDITIONING PANEL | |||||
| Multi-display(2) | REMOVAL | |||||
| A/C amplifier | AIR CONDITIONING AMPLIFIER | |||||
| Air Flow Control No blower control | Blower motor circuit | BLOWER MOTOR CIRCUIT | ||||
| Integration control and panel assembly(1) | AIR CONDITIONING PANEL | |||||
| Multi-display(2) | REMOVAL | |||||
| A/C amplifier | AIR CONDITIONING AMPLIFIER | |||||
| Air Flow Control Insufficient air flow | Blower motor circuit | BLOWER MOTOR CIRCUIT | ||||
| A/C amplifier | AIR CONDITIONING AMPLIFIER | |||||
| Temperature Control No cool air comes out | Refrigerant volume | REFRIGERANT | ||||
| Refrigerant pressure | REFRIGERANT | |||||
| Pressure sensor circuit | DTC B1423/23 PRESSURE SENSOR CIRCUIT | |||||
| Compressor solenoid circuit | DTC B1451/51 COMPRESSOR SOLENOID CIRCUIT | |||||
| Air mix control servo motor circuit (Driver side) | DTC B1446/46 AIR MIX DAMPER CONTROL SERVO MOTOR CIRCUIT (DRIVER SIDE) | |||||
| Air mix control servo motor circuit (Passenger side) | DTC B1441/41 AIR MIX DAMPER CONTROL SERVO MOTOR CIRCUIT (PASSENGER SIDE) | |||||
| Evaporator temperature sensor circuit | DTC B1413/13 EVAPORATOR TEMPERATURE SENSOR CIRCUIT | |||||
| Room temperature sensor circuit | DTC B1411/11 ROOM TEMPERATURE SENSOR CIRCUIT | |||||
| Ambient temperature sensor circuit | DTC B1412/12 AMBIENT TEMPERATURE SENSOR CIRCUIT | |||||
| Expansion valve | AIR CONDITIONING UNIT | |||||
| Integration control and panel assembly(1) | AIR CONDITIONING PANEL | |||||
| Multi-display(2) | REMOVAL | |||||
| A/C amplifier | AIR CONDITIONING AMPLIFIER | |||||
| ECM | REMOVAL | |||||
| Temperature Control No warm air comes out | Air mix control servo motor circuit (Driver side) | DTC B1446/46 AIR MIX DAMPER CONTROL SERVO MOTOR CIRCUIT (DRIVER SIDE) | ||||
| Air mix control servo motor circuit (Passenger side) | DTC B1441/41 AIR MIX DAMPER CONTROL SERVO MOTOR CIRCUIT (PASSENGER SIDE) | |||||
| Evaporator temperature sensor circuit | DTC B1413/13 EVAPORATOR TEMPERATURE SENSOR CIRCUIT | |||||
| Room temperature sensor circuit | DTC B1411/11 ROOM TEMPERATURE SENSOR CIRCUIT | |||||
| Ambient temperature sensor circuit | DTC B1412/12 AMBIENT TEMPERATURE SENSOR CIRCUIT | |||||
| Integration control and panel assembly(1) | AIR CONDITIONING PANEL | |||||
| Multi-display(2) | REMOVAL | |||||
| A/C amplifier | AIR CONDITIONING AMPLIFIER | |||||
| ECM | REMOVAL | |||||
| Temperature Control Output air is warmer or cooler than the set temperature or response is slow | Refrigerant volume | REFRIGERANT | ||||
| Refrigerant pressure | REFRIGERANT | |||||
| Solar sensor circuit (Driver side) | DTC B1424/24 SOLAR SENSOR CIRCUIT (DRIVER SIDE) | |||||
| Solar sensor circuit (Passenger side) | DTC B1421/21 SOLAR SENSOR CIRCUIT (PASSENGER SIDE) | |||||
| Room temperature sensor circuit | DTC B1411/11 ROOM TEMPERATURE SENSOR CIRCUIT | |||||
| Ambient temperature sensor circuit | DTC B1412/12 AMBIENT TEMPERATURE SENSOR CIRCUIT | |||||
| Air mix control servo motor circuit (Driver side) | DTC B1446/46 AIR MIX DAMPER CONTROL SERVO MOTOR CIRCUIT (DRIVER SIDE) | |||||
| Air mix control servo motor circuit (Passenger side) | DTC B1441/41 AIR MIX DAMPER CONTROL SERVO MOTOR CIRCUIT (PASSENGER SIDE) | |||||
| Cool air bypass damper control servo motor circuit | DTC B1445/45 FRONT PASSENGER SEAT SIDE COOL AIR BYPASS DAMPER CONTROL SERVO MOTOR CIRCUIT | |||||
| Air inlet control servo motor circuit | DTC B1442/42 AIR INLET DAMPER CONTROL SERVO MOTOR CIRCUIT | |||||
| Radiator unit sub-assembly | AIR CONDITIONING UNIT | |||||
| Expansion valve | AIR CONDITIONING UNIT | |||||
| Integration control and panel assembly(1) | AIR CONDITIONING PANEL | |||||
| Multi-display(2) | REMOVAL | |||||
| A/C amplifier | AIR CONDITIONING AMPLIFIER | |||||
| ECM | REMOVAL | |||||
| Temperature control No temperature control (only Max cool or Max warm) | Air mix control servo motor circuit (Driver side) | DTC B1446/46 AIR MIX DAMPER CONTROL SERVO MOTOR CIRCUIT (DRIVER SIDE) | ||||
| Air mix control servo motor circuit (Passenger side) | DTC B1441/41 AIR MIX DAMPER CONTROL SERVO MOTOR CIRCUIT (PASSENGER SIDE) | |||||
| Cool air bypass damper servo motor circuit | DTC B1445/45 FRONT PASSENGER SEAT SIDE COOL AIR BYPASS DAMPER CONTROL SERVO MOTOR CIRCUIT | |||||
| Room temperature sensor circuit | DTC B1411/11 ROOM TEMPERATURE SENSOR CIRCUIT | |||||
| Ambient temperature sensor circuit | DTC B1412/12 AMBIENT TEMPERATURE SENSOR CIRCUIT | |||||
| Evaporator temperature sensor circuit | DTC B1413/13 EVAPORATOR TEMPERATURE SENSOR CIRCUIT | |||||
| Solar sensor circuit (Driver side) | DTC B1424/24 SOLAR SENSOR CIRCUIT (DRIVER SIDE) | |||||
| Solar sensor circuit (Passenger side) | DTC B1421/21 SOLAR SENSOR CIRCUIT (PASSENGER SIDE) | |||||
| Integration control and panel assembly(1) | AIR CONDITIONING PANEL | |||||
| Multi-display(2) | REMOVAL | |||||
| A/C amplifier | AIR CONDITIONING AMPLIFIER | |||||
| No air inlet control | Air inlet control servo motor circuit | DTC B1442/42 AIR INLET DAMPER CONTROL SERVO MOTOR CIRCUIT | ||||
| Integration control and panel assembly(1) | AIR CONDITIONING PANEL | |||||
| Multi-display(2) | REMOVAL | |||||
| A/C amplifier | AIR CONDITIONING AMPLIFIER | |||||
| No air flow mode control | Air outlet control servo motor circuit | DTC B1443/43 AIR OUTLET DAMPER CONTROL SERVO MOTOR CIRCUIT | ||||
| Integration control and panel assembly(1) | AIR CONDITIONING PANEL | |||||
| Multi-display(2) | REMOVAL | |||||
| A/C amplifier | AIR CONDITIONING AMPLIFIER | |||||
| Engine idle up does not occur, or is continuous | Compressor solenoid circuit | DTC B1451/51 COMPRESSOR SOLENOID CIRCUIT | ||||
| A/C amplifier | AIR CONDITIONING AMPLIFIER | |||||
| Blinking of A/C indicator | Compressor solenoid circuit | DTC B1451/51 COMPRESSOR SOLENOID CIRCUIT | ||||
| A/C amplifier | AIR CONDITIONING AMPLIFIER | |||||
| Diagnostic trouble codes are not recorded Set mode is cleared when engine switch is off | Back-up power source circuit | BACK-UP POWER SOURCE CIRCUIT | ||||
| A/C amplifier | AIR CONDITIONING AMPLIFIER | |||||
|
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