Air Conditioning (Diagnostic Codes & Circuit Tests): Overview Lexus LX J200

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1. ACTUATOR CHECK Turn the engine switch on (IG) while pressing the A/C control AUTO switch and recirculation/fresh switch simultaneously. Press the recirculation/fresh switch. By performing the actuator check, each damper, motor, and relay are automatically operated at 1 second intervals in a continuous cycle from step No. 1 to No. 10. During this operation, check the temperature and airflow indicated on the display as well as by hand. HINT: If a slower display is desired, press the driver temperature up switch to stop the automatic display. The display changes to step operation display mode which allows the display to be changed 1 step for each press of the switch. The buzzer sounds when the display code changes. Codes are displayed from smaller to larger numbers in order. To cancel the check mode, press the OFF switch. FRONT AIR CONDITIONING UNIT Step No. Display Code Conditions Blower Level Air Mix Damper Dr. Pa. Air Mix Damper FrRr Dr. Pa. Airflow Vent Dr. Pa. Airflow Vent FrRr Air Inlet Cool Air Bypass Damper Compressor 1 0 0 0% 0% FACE FACE FRESH -14% OFF 2 1 1 3 2 17 RECIRCULATION/FRESH ON 4 3 17 RECIRCULATION 113.0% 5 4 17 50% 50% B/L B/L 6 5 17 7 6 17 FOOT FOOT FRESH 8 7 17 100% 100% FOOT 9 8 17 F/D 10 9 31 DEF 113.5% REAR AIR CONDITIONING UNIT Step No. Display Code Conditions Rear Blower Level Rear Air Mix Damper Dr. Pa. Rear Airflow Vent Dr. Pa. Rear Magnetic Valve 1 0 0 0% FACE OFF 2 1 3 3 2 17 ON 4 3 17 5 4 17 50% B/L OFF 6 5 17 7 6 17 FOOT 8 7 17 100% 9 8 17 10 9 31

DESCRIPTION

The front room temperature sensor for the front seat is installed in the instrument panel to detect the room temperature and control the heater and air conditioner auto mode. The resistance of the room temperature sensor changes in accordance with the front room temperature. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.

The air conditioning amplifier assembly applies voltage (5 V) to the front room temperature sensor and reads voltage changes as the resistance of the front room temperature sensor changes. This sensor also sends the appropriate signals to the air conditioning amplifier assembly.

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1. READ VALUE USING TECHSTREAM (FRONT ROOM TEMPERATURE SENSOR) Use the Data List to check if the front room temperature sensor is functioning properly. AIR CONDITIONER Tester Display Measurement Item/Range Normal Condition Diagnostic Note Room Temperature Sensor Front room temperature sensor / Min.: -6.5°C (20.3°F) Max.: 57.25°C (135.05°F) Actual room temperature for front seat displayed Open in the circuit: -6.5°C (20.3°F). Short in the circuit: 57.25°C (135.05°F). OK The display is as specified in the normal condition. NG --> See step 2 OK --> See step 4
2. INSPECT FRONT ROOM TEMPERATURE SENSOR Remove the front room temperature sensor. Refer to «REMOVAL». Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 1 (+) - 2 (-) 10°C (50°F) 3.00 to 3.73 kohms 15°C (59°F) 2.45 to 2.88 kohms 20°C (68°F) 1.95 to 2.30 kohms 25°C (77°F) 1.60 to 1.80 kohms 30°C (86°F) 1.28 to 1.47 kohms 35°C (95°F) 1.00 to 1.22 kohms 40°C (104°F) 0.80 to 1.00 kohms 45°C (113°F) 0.65 to 0.85 kohms 50°C (122°F) 0.50 to 0.70 kohms 55°C (131°F) 0.44 to 0.60 kohms 60°C (140°F) 0.36 to 0.50 kohms NOTE: Even slightly touching the sensor may change the resistance value. Be sure to hold the connector of the sensor. When measuring, the sensor temperature must be the same as the ambient temperature. HINT: As the temperature increases, the resistance decreases (See the graph). NG --> See step 5 OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (ROOM TEMPERATURE SENSOR - AIR CONDITIONING AMPLIFIER) Disconnect the E32 sensor connector. Disconnect the E35 amplifier connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition E32-1 (+) - E35-9 (TR) Always Below 1 ohms E32-2 (-) - E35-32 (SG-1) E35-9 (TR) - Body ground Always 10 kohms or higher E35-32 (SG-1) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 4
4. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
5. REPLACE FRONT ROOM TEMPERATURE SENSOR. Refer to «REMOVAL»

The ambient temperature sensor is installed in the front part of the condenser to detect the ambient temperature and control the air conditioner auto mode. The sensor connected to the air conditioning amplifier assembly detects fluctuations in the ambient temperature. This data is used for controlling the room temperature. The sensor sends a signal to the air conditioning amplifier assembly. The resistance of the ambient temperature sensor changes in accordance with the ambient temperature. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.

The air conditioning amplifier assembly applies voltage (5 V) to the ambient temperature sensor and reads voltage changes as the resistance of the ambient temperature sensor changes.

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1. READ VALUE USING TECHSTREAM (AMBIENT TEMPERATURE SENSOR) Use the Data List to check if the ambient temperature sensor is functioning properly. AIR CONDITIONER Tester Display Measurement Item/Range Normal Condition Diagnostic Note Ambient Temp Sensor Ambient temperature sensor / Min: -23.3°C (-9.94°F) Max: 65.95°C (150.71°F) Actual ambient temperature displayed Open in the circuit: -23.3°C (-9.94°F). Short in the circuit: 65.95°C (150.71°F). OK The display is as specified in the normal condition. NG --> See step 2 OK --> See step 5
2. INSPECT AMBIENT TEMPERATURE SENSOR Remove the ambient temperature sensor. Refer to «REMOVAL». Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 1 (+) - 2 (-) 10°C (50°F) 3.00 to 3.73 kohms 15°C (59°F) 2.45 to 2.88 kohms 20°C (68°F) 1.95 to 2.30 kohms 25°C (77°F) 1.60 to 1.80 kohms 30°C (86°F) 1.28 to 1.47 kohms 35°C (95°F) 1.00 to 1.22 kohms 40°C (104°F) 0.80 to 1.00 kohms 45°C (113°F) 0.65 to 0.85 kohms 50°C (122°F) 0.50 to 0.70 kohms 55°C (131°F) 0.44 to 0.60 kohms 60°C (140°F) 0.36 to 0.50 kohms NOTE: Even slightly touching the sensor may change the resistance value. Be sure to hold the connector of the sensor. When measuring, the sensor temperature must be the same as the ambient temperature. HINT: As the temperature increases, the resistance decreases (See the graph). NG --> See step 6 OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (AMBIENT TEMPERATURE SENSOR - AIR CONDITIONING AMPLIFIER) Disconnect the A14 sensor connector. Disconnect the E35 amplifier connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A14-1 (+) - E35-10 (TAM) Always Below 1 ohms A14-2 (-) - E35-16 (SG-2) E35-10 (TAM) - Body ground Always 10 kohms or higher E35-16 (SG-2) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 4
4. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
5. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
6. REPLACE AMBIENT TEMPERATURE SENSOR. Refer to «REMOVAL»

The No. 1 cooler thermistor is installed on the evaporator in the air conditioner unit to detect the cooled air temperature that has passed through the evaporator and control the air conditioning. It sends appropriate signals to the air conditioning amplifier assembly. The resistance of the No. 1 cooler thermistor changes in accordance with the cooled air temperature that has passed through the evaporator. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.

The air conditioning amplifier assembly applies voltage (5 V) to the No. 1 cooler thermistor and reads voltage changes as the resistance of the No. 1 cooler thermistor changes. This sensor is used for frost prevention.

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1. READ VALUE USING TECHSTREAM (NO. 1 COOLER THERMISTOR) Use the Data List to check if the No. 1 cooler thermistor is functioning properly. AIR CONDITIONER Tester Display Measurement Item/Range Normal Condition Diagnostic Note Evaporator Fin Thermistor No. 1 cooler thermistor / Min.: -29.7°C (-21.46°F) Max.: 59.55°C (139.19°F) Actual evaporator temperature displayed Open in the circuit: -29.7°C (-21.46°F). Short in the circuit: 59.55°C (139.19°F). OK The display is as specified in the normal condition. NG --> See step 2 OK --> See step 4
2. INSPECT NO. 1 COOLER THERMISTOR Remove the No. 1 cooler thermistor. Refer to «DISASSEMBLY». Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 1 (+) - 2 (-) -10°C (14°F) 7.30 to 9.10 kohms -5°C (23°F) 5.65 to 6.95 kohms 0°C (32°F) 4.40 to 5.35 kohms 5°C (41°F) 3.40 to 4.15 kohms 10°C (50°F) 2.70 to 3.25 kohms 15°C (59°F) 2.14 to 2.58 kohms 20°C (68°F) 1.71 to 2.05 kohms 25°C (77°F) 1.38 to 1.64 kohms 30°C (86°F) 1.11 to 1.32 kohms NOTE: Even slightly touching the sensor may change the resistance value. Be sure to hold the connector of the sensor. When measuring, the sensor temperature must be the same as the ambient temperature. HINT: As the temperature increases, the resistance decreases (See the graph). NG --> See step 5 OK --> See step 3
3. REPLACE AIR CONDITIONING HARNESS ASSEMBLY. Refer to «DISASSEMBLY»
4. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
5. REPLACE NO. 1 COOLER THERMISTOR. Refer to «DISASSEMBLY»

The rear evaporator temperature sensor is installed on the evaporator in the rear air conditioning unit to detect the cooled air temperature that has passed through the evaporator and control the air conditioning. It sends appropriate signals to the air conditioning amplifier assembly. The resistance of the rear evaporator temperature sensor changes in accordance with the cooled air temperature that has passed through the rear evaporator. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.

The air conditioning amplifier assembly applies voltage (5 V) to the rear evaporator temperature sensor and reads voltage changes as the resistance of the rear evaporator temperature sensor changes. This sensor is used for frost prevention.

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1. READ VALUE USING TECHSTREAM (REAR EVAPORATOR TEMPERATURE SENSOR) Use the Data List to check if the rear evaporator temperature sensor is functioning properly. AIR CONDITIONER Tester Display Measurement Item/Range Normal Condition Diagnostic Note Ambient Temp Sens (Rear) Rear evaporator temperature sensor / Min.: -29.7°C (-21.46°F) Max.: 59.55°C (139.19°F) Actual rear evaporator temperature displayed Open in the circuit: -29.7°C (-21.46°F). Short in the circuit: 59.55°C (139.19°F). OK The display is as specified in the normal condition. NG --> See step 2 OK --> See step 7
2. INSPECT REAR EVAPORATOR TEMPERATURE SENSOR Remove the No. 2 air conditioning harness assembly. Refer to «DISASSEMBLY». Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 7 (-) - 8 (+) -10°C (14°F) 7.30 to 9.10 kohms -5°C (23°F) 5.65 to 6.95 kohms 0°C (32°F) 4.40 to 5.35 kohms 5°C (41°F) 3.40 to 4.15 kohms 10°C (50°F) 2.70 to 3.25 kohms 15°C (59°F) 2.14 to 2.58 kohms 20°C (68°F) 1.71 to 2.05 kohms 25°C (77°F) 1.38 to 1.64 kohms 30°C (86°F) 1.11 to 1.32 kohms NOTE: Even slightly touching the sensor may change the resistance value. Be sure to hold the connector of the sensor. When measuring, the sensor temperature must be the same as the ambient temperature. HINT: As the temperature increases, the resistance decreases (See the graph). NG --> See step 8 OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (NO. 2 AIR CONDITIONING HARNESS - AIR CONDITIONING AMPLIFIER) Disconnect the K19 No. 2 air conditioning harness assembly connector. Disconnect the E35 amplifier connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition K19-8 (+) - E35-17 (TEC) Always Below 1 ohms K19-7 (-) - E35-1 (SG) Always Below 1 ohms E35-17 (TEC) - Body ground Always 10 kohms or higher E35-1 (SG) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK NO. 2 AIR CONDITIONING HARNESS ASSEMBLY (OPERATION) Replace the No. 2 air conditioning harness assembly with a normal one and check that the condition returns to normal. Refer to «DISASSEMBLY». NEXT: Go to next step
5. CHECK FOR DTC Clear the DTCs. Refer to «DTC CHECK / CLEAR». Check for DTCs. Refer to «DTC CHECK / CLEAR». OK DTC B1417 is not output. NG --> See step 9 OK --> See step 6
6. REPLACE NO. 2 AIR CONDITIONING HARNESS ASSEMBLY. Refer to «DISASSEMBLY»
7. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
8. REPLACE NO. 2 AIR CONDITIONING HARNESS ASSEMBLY. Refer to «DISASSEMBLY»
9. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»

The smog ventilation sensor, which is installed on the front of the cooler condenser assembly, automatically changes to fresh, fresh/recirculation or recirculation mode operation. The smog ventilation sensor detects CO and HC in the emission gas and transmits signals to the air conditioning amplifier assembly.

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1. INSPECT FUSE (A/C IG) Remove the A/C IG fuse from the cowl side junction block LH. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A/C IG fuse Always Below 1 ohms NG --> REPLACE FUSE OK: Go to next step
2. READ VALUE USING TECHSTREAM (SMOG VENTILATION SENSOR) Use the Data List to check if the smog ventilation sensor is functioning properly. AIR CONDITIONER Tester Display Measurement Item / Range Normal Condition Diagnostic Note Emission Gas Sensor Smog ventilation sensor / Min.: 0, Max.: 255 Decreases as the gas amount increases - OK The display is as specified in the normal condition. NG --> See step 3 OK --> See step 8
3. CHECK HARNESS AND CONNECTOR (SMOG VENTILATION SENSOR - BODY GROUND) Disconnect the A45 smog ventilation sensor connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A45-6 (E) - Body ground Always Below 1 ohms NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK HARNESS AND CONNECTOR (SMOG VENTILATION SENSOR - BATTERY) Disconnect the A45 smog ventilation sensor connector. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition A45-3 (IG) - Body ground Engine switch on (IG) 11 to 14 V NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
5. INSPECT SMOG VENTILATION SENSOR Remove the smog ventilation sensor. Refer to «REMOVAL». After applying battery voltage to terminals 3 (IG) and 6 (E) for more than 30 seconds, measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 1 (SG) - 2 (DGS) 15 to 25°C (59 to 77°F) 15 to 40 kohms HINT: When the sensor is exposed to the exhaust gas, the resistance decreases. NG --> See step 9 OK: Go to next step
6. CHECK HARNESS AND CONNECTOR (SMOG VENTILATION SENSOR - AIR CONDITIONING AMPLIFIER) Disconnect the A45 smog ventilation sensor connector. Disconnect the E35 amplifier connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A45-1 (SG) - E35-30 (SG-4) Always Below 1 ohms A45-2 (DGS) - E35-23 (DGS) E35-30 (SG-4) - Body ground Always 10 kohms or higher E35-23 (DGS) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 7
7. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
8. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
9. REPLACE SMOG VENTILATION SENSOR. Refer to «REMOVAL»

The rear room temperature sensor LH is installed in the rear quarter trim board LH to detect the rear room temperature and control the heater and air conditioner auto mode. The resistance of the rear room temperature sensor LH changes in accordance with the rear room temperature for the LH seat. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.

The air conditioning amplifier assembly applies a voltage (5 V) to the rear room temperature sensor LH and reads voltage changes as changes in the resistance of the rear room temperature sensor LH.

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1. READ VALUE USING TECHSTREAM (REAR ROOM TEMPERATURE SENSOR LH) Use the Data List to check if the rear room temperature sensor LH is functioning properly. AIR CONDITIONER Tester Display Measurement Item/Range Normal Condition Diagnostic Note Room Temp Sensor (Rear) Rear room temperature sensor LH / Min.: -6.5°C (20.3°F) Max.: 57.25°C (135.05°F) Actual rear room temperature for LH seat displayed Open in the circuit: -6.5°C (20.3°F). Short in the circuit: 57.25°C (135.05°F). OK The display is as specified in the normal condition. NG --> See step 2 OK --> See step 5
2. INSPECT REAR ROOM TEMPERATURE SENSOR LH Remove the rear room temperature sensor LH. Refer to «REMOVAL». Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 1 (+) - 2 (-) 10°C (50°F) 3.00 to 3.73 kohms 15°C (59°F) 2.45 to 2.88 kohms 20°C (68°F) 1.95 to 2.30 kohms 25°C (77°F) 1.60 to 1.80 kohms 30°C (86°F) 1.28 to 1.47 kohms 35°C (95°F) 1.00 to 1.22 kohms 40°C (104°F) 0.80 to 1.00 kohms 45°C (113°F) 0.65 to 0.85 kohms 50°C (122°F) 0.50 to 0.70 kohms 55°C (131°F) 0.44 to 0.60 kohms 60°C (140°F) 0.36 to 0.50 kohms NOTE: Even slightly touching the sensor may change the resistance value. Be sure to hold the connector of the sensor. HINT: As the temperature increases, the resistance decreases (See the graph). NG --> See step 6 OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (REAR ROOM TEMPERATURE SENSOR LH - AIR CONDITIONING AMPLIFIER) Disconnect the Z38 sensor connector. Disconnect the E35 amplifier connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition Z38-1 (+) - E35-18 (TR) Always Below 1 ohms Z38-2 (-) - E35-2 (SG-6) E35-18 (TR) - Body ground Always 10 kohms or higher E35-2 (SG-6) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 4
4. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
5. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
6. REPLACE REAR ROOM TEMPERATURE SENSOR LH. Refer to «REMOVAL»

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The automatic light control sensor (solar sensor), which is installed on the upper side of the instrument panel, detects sunlight and controls the air conditioning in auto mode. The output current from the solar sensor varies according to the amount of sunlight. When the sunlight increases, the output current increases. As the sunlight decreases, the output current decreases. The air conditioning amplifier assembly detects output current from the solar sensor.

HINT

If DTC B1244 is output at the same time, troubleshoot DTC B1244 first.

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1. READ VALUE USING TECHSTREAM (FRONT PASSENGER SIDE SOLAR SENSOR) Use the Data List to check if the front passenger side solar sensor is functioning properly. AIR CONDITIONER Tester Display Measurement Item/Range Normal Condition Diagnostic Note Solar Sensor (P Side) Passenger side solar sensor / Min.: 0, Max.: 255 Passenger side solar sensor voltage increases as brightness increases Open in the circuit: 0. Short in the circuit: 255. OK The display is as specified in the normal condition. NG --> See step 2 OK --> See step 5
2. CHECK HARNESS AND CONNECTOR (AUTOMATIC LIGHT CONTROL SENSOR - AIR CONDITIONING AMPLIFIER) Disconnect the F9 sensor connector. Disconnect the E35 amplifier connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition F9-2 (TSR) - E35-8 (TSP) Always Below 1 ohms E35-8 (TSP) - Body ground Always 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. INSPECT AUTOMATIC LIGHT CONTROL SENSOR (TSR - CLTE VOLTAGE) Remove the automatic light control sensor. Refer to «REMOVAL». Apply battery voltage between terminals 6 (CLTB) and 3 (CLTE) of the solar sensor. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Condition Specified Condition 2 (TSR) - 3 (CLTE) Sensor exposed to electric light 0.8 to 4.3 V Sensor covered with a cloth Below 0.8 V HINT: As the inspection light is moved away from the sensor, the voltage decreases. Use an incandescent light for inspection. Bring it about 300 mm (11.8 in.) from the solar sensor. NG --> See step 6 OK: Go to next step
4. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - AUTOMATIC LIGHT CONTROL SENSOR) Disconnect the E2 ECU connector. Disconnect the F9 sensor connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition E2-20 (CLTB) - F9-6 (CLTB) Always Below 1 ohms E2-19 (CLTS) - F9-5 (CLTS) E2-18 (CLTE) - F9-3 (CLTE) E2-20 (CLTB) - Body ground Always 10 kohms or higher E2-19 (CLTS) - Body ground E2-18 (CLTE) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> REPLACE MAIN BODY ECU (COWL SIDE JUNCTION BLOCK LH)
5. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
6. REPLACE AUTOMATIC LIGHT CONTROL SENSOR. Refer to «REMOVAL»

SYSTEM DESCRIPTION

The ECM sends the engine speed signal to the air conditioning amplifier assembly via CAN communication.

The air conditioning amplifier assembly reads the difference between compressor speed and engine speed. When the difference becomes too large, the air conditioning amplifier assembly determines that the compressor is locked, and turns the magnetic clutch off.

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1. CHECK CAN COMMUNICATION SYSTEM Use the Techstream to check if the CAN communication system is functioning normally. RESULT Result Proceed to CAN DTC is not output A CAN DTC is output B B --> See step 5 A: Go to next step
2. INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY Remove the air conditioning amplifier assembly with its connectors still connected. Refer to «REMOVAL». Measure the waveform of the connector. MEASUREMENT CONDITION Item Content Terminal No. (Symbol) E35-28 (LOCK) - E35-29 (SG-5) Tool Setting 200 mV/DIV., 10 ms/DIV. Condition Engine running A/C switch on Blower switch lo OK Waveform is as shown in the illustration. NG --> See step 3 OK --> See step 6
3. INSPECT COOLER COMPRESSOR ASSEMBLY (A/C LOCK SENSOR) Disconnect the C37 cooler compressor assembly connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition C37-1 (SSR+) - C37-2 (SSR-) 20°C (68°F) 65 to 125 ohms NG --> REPLACE COOLER COMPRESSOR ASSEMBLY (A/C LOCK SENSOR) OK: Go to next step
4. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - COOLER COMPRESSOR) Disconnect the E35 amplifier connector. Disconnect the C37 cooler compressor assembly connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition E35-28 (LOCK) - C37-1 (SSR+) Always Below 1 ohms E35-29 (SG-5) - C37-2 (SSR-) E35-28 (LOCK) - Body ground Always 10 kohms or higher E35-29 (SG-5) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 7
5. GO TO CAN COMMUNICATION SYSTEM. Refer to «HOW TO PROCEED WITH TROUBLESHOOTING»
6. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
7. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»

This DTC is stored when refrigerant pressure is extremely low (0.1762 MPa (1.8 kgf/cm 2 , 25 psi) or less) or extremely high (3.0732 MPa (31.4 kgf/cm 2 , 445 psi) or more). The air conditioner pressure sensor, which is installed on the pipe of the high pressure side to detect refrigerant pressure, outputs the refrigerant pressure signal to the air conditioning amplifier assembly. The air conditioning amplifier assembly converts the signal to pressure according to the sensor characteristics to control the compressor.

HINT

Be sure to check the refrigerant volume first when this DTC is output because this DTC can also be stored if there is no refrigerant in the cycle.

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1. INSPECT AIR CONDITIONER PRESSURE SENSOR (POWER SOURCE CIRCUIT) Disconnect the A13 air conditioner pressure sensor connector. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition A13-3 (+) - Body ground Engine switch on (IG) 4.75 to 5.25 V NG --> See step 5 OK: Go to next step
2. INSPECT AIR CONDITIONER PRESSURE SENSOR (GROUND CIRCUIT) Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A13-1 (-) - Body ground Always Below 1 ohms NG --> See step 6 OK: Go to next step
3. INSPECT AIR CONDITIONER PRESSURE SENSOR (SENSOR SIGNAL CIRCUIT) Reconnect the A13 air conditioner pressure sensor connector. Remove the air conditioning amplifier assembly with its connectors still connected. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition E35-20 (PRE) - Body ground Engine switch on (IG) A/C switch off 0.7 to 4.8 V HINT: If the measured voltage is not within the normal range, there may be a malfunction in the air conditioning amplifier assembly, air conditioner pressure sensor, or wire harness. It is also possible that the amount of refrigerant may not be appropriate. NG --> See step 7 OK: Go to next step
4. INSPECT AIR CONDITIONER PRESSURE SENSOR (SENSOR SIGNAL CIRCUIT) Measure the voltage when the following conditions are satisfied. MEASUREMENT CONDITION Item Condition Engine Speed 1500 rpm Vehicle Doors Fully open Temperature Setting Lo Blower Speed Hi A/C Switch On R/F Switch Recirculation Interior Temperature 25 to 35°C (77 to 95°F) NOTE: If refrigerant pressure on the high pressure side becomes extremely high during the inspection (if the voltage exceeds 4.8 V), the fail-safe function stops compressor operation. Therefore, measure the voltage before the fail-safe operation. It is necessary to measure the voltage for a certain amount of time (approximately 10 minutes) because the problem symptom may recur after a while. HINT: When the outside air temperature is low (below -1.5°C (29.3°F)), the compressor stops due to operation of the ambient temperature and the evaporator temperature sensor to prevent the evaporator from freezing. In this case, perform the inspection in a warm indoor environment. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition E35-20 (PRE) - Body ground Engine switch on (IG) A/C switch on 0.7 to 4.8 V NG --> See step 13 OK --> See step 19
5. CHECK HARNESS AND CONNECTOR (PRESSURE SENSOR - AIR CONDITIONING AMPLIFIER) Disconnect the E35 air conditioning amplifier assembly connector. Disconnect the A13 air conditioner pressure sensor connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A13-3 (+) - E35-27 (S5-1) Always Below 1 ohms E35-27 (S5-1) - Body ground Always 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 19
6. CHECK HARNESS AND CONNECTOR (PRESSURE SENSOR - AIR CONDITIONING AMPLIFIER) Disconnect the E35 air conditioning amplifier assembly connector. Disconnect the A13 air conditioner pressure sensor connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A13-1 (-) - E35-16 (SG-2) Always Below 1 ohms E35-16 (SG-2) - Body ground Always 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 19
7. CHECK HARNESS AND CONNECTOR (PRESSURE SENSOR - AIR CONDITIONING AMPLIFIER) Disconnect the E35 air conditioning amplifier assembly connector. Disconnect the A13 air conditioner pressure sensor connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A13-2 (PR) - E35-20 (PRE) Always Below 1 ohms E35-20 (PRE) - Body ground Always 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
8. INSPECT FOR AIR CONDITIONING SYSTEM LEAK Install the manifold gauge set. Recover the refrigerant from the air conditioning system using a refrigerant recovery unit. Evacuate the air conditioning system and check that vacuum can be maintained in it. OK Vacuum can be maintained in the air conditioning system. HINT: If vacuum cannot be maintained in the air conditioning system, refrigerant may be leaking from it. In this case, it is necessary to repair or replace the leaking part of the air conditioning system. NG --> See step 12 OK: Go to next step
9. CHARGE REFRIGERANT Add an appropriate amount of refrigerant. Refer to «REPLACEMENT». NEXT: Go to next step
10. RECHECK DTC Recheck for the DTC when the following conditions are satisfied. MEASUREMENT CONDITION Item Condition Engine Speed 1500 rpm Vehicle Doors Fully open Temperature Setting Lo Blower Speed Hi A/C Switch On R/F Switch Recirculation Interior Temperature 25 to 35°C (77 to 95°F) NOTE: If refrigerant pressure on the high pressure side becomes high, the DTC will be stored. Therefore, it is necessary to measure the voltage for a certain amount of time (approximately 10 minutes) because the DTC may be stored after the air conditioning system operates for a while. HINT: When the outside air temperature is low (below -1.5°C (29.3°F)), the compressor stops due to operation of the ambient temperature sensor and the evaporator temperature sensor to prevent the evaporator from freezing. In this case, perform the inspection in a warm indoor environment. OK DTC B1423 is not output. NOTE: If the DTC was stored due to an insufficient or excessive amount of refrigerant, the problem may have been solved after performing the previous step. However, the root cause of insufficient refrigerant may be refrigerant leaks. The root cause of excessive refrigerant may be adding refrigerant when the level was insufficient. Therefore, identify and repair the area where refrigerant leaks as necessary. NG --> See step 11 OK --> END
11. CHECK AIR CONDITIONER PRESSURE SENSOR Install the manifold gauge set. Reconnect the A13 air conditioner pressure sensor connector. Remove the air conditioning amplifier assembly with its connectors still connected. Turn the engine switch on (IG). Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Condition Specified Condition E35-20 (PRE) - E35-16 (SG-2) Refrigerant pressure: Normal pressure (less than 3.0732 MPa [31.4 kgf/cm 2 , 445 psi] and more than 0.1762 MPa [1.8 kgf/cm 2 , 25 psi]) 1.0 to 4.8 V Refrigerant pressure: Abnormal (less than 0.1762 MPa [1.8 kgf/cm 2 , 25 psi]) Below 1 V Refrigerant pressure: Abnormal (more than 3.0732 MPa [31.4 kgf/cm 2 , 445 psi]) 4.8 V or higher NG --> See step 20 OK --> See step 19
12. REPAIR AIR CONDITIONING SYSTEM LEAK Identify the area where refrigerant leaks. Refer to «REPLACEMENT». Repair the identified area of the air conditioning system. Evacuate the air conditioning system. NEXT --> See step 21
13. INSPECT CONDENSER FAN Inspect that the condenser fan operates normally. Refer to «REMOVAL». NG --> See step 22 OK: Go to next step
14. CHARGE REFRIGERANT Use a refrigerant recovery unit to recover refrigerant. Evacuate the air conditioning system. Add an appropriate amount of refrigerant. Refer to «REPLACEMENT». HINT: If refrigerant is added and the system has not been properly evacuated (insufficient vacuum time), moisture in the air remaining in the system will freeze in the expansion valve, blocking the flow on the high pressure side. Therefore, in order to confirm the problem, recover the refrigerant and properly evacuate the system. Add an appropriate amount of refrigerant, and check for the DTC. NEXT: Go to next step
15. RECHECK DTC Recheck for the DTC when the following conditions are satisfied. MEASUREMENT CONDITION Item Condition Engine Speed 1500 rpm Vehicle Doors Fully open Temperature Setting Lo Blower Speed Hi A/C Switch On R/F Switch Recirculation Interior Temperature 25 to 35°C (77 to 95°F) NOTE: If refrigerant pressure on the high pressure side becomes high, the DTC will be stored. Therefore, it is necessary to measure the voltage for a certain amount of time (approximately 10 minutes) because the DTC may be stored after the air conditioning system operates for a while. HINT: When the outside air temperature is low (below -1.5°C (29.3°F)), the compressor stops due to operation of the ambient temperature sensor and the evaporator temperature sensor to prevent the evaporator from freezing. In this case, perform the inspection in a warm indoor environment. If refrigerant is added and the system has not been properly evacuated (insufficient vacuum time), moisture in the air remaining in the system will freeze in the expansion valve, blocking the flow on the high pressure side. Therefore, in order to confirm the problem, recover the refrigerant and properly evacuate the system. Add an appropriate amount of refrigerant, and check for the DTC. If the DTC is not output after this procedure, it indicates that the cooler dryer in the cooler condenser assembly is not able to absorb moisture in the refrigerant cycle. In this case, to complete the repair it is necessary to replace the cooler dryer. OK DTC B1423 is not output. NG --> See step 16 OK --> See step 23
16. REPLACE COOLER EXPANSION VALVE Replace the cooler expansion valve with a normal one. Refer to «DISASSEMBLY». HINT: Replace the cooler expansion valve with a normal one because the cooler expansion valve is either stuck or clogged. NEXT: Go to next step
17. CHARGE REFRIGERANT Add an appropriate amount of refrigerant. Refer to «REPLACEMENT». NEXT: Go to next step
18. RECHECK DTC Recheck for the DTC when the following conditions are satisfied. MEASUREMENT CONDITION Item Condition Engine Speed 1500 rpm Vehicle Doors Fully open Temperature Setting Lo Blower Speed Hi A/C Switch On R/F Switch Recirculation Interior Temperature 25 to 35°C (77 to 95°F) NOTE: If refrigerant pressure on the high pressure side becomes high, the DTC will be stored. Therefore, it is necessary to measure the voltage for a certain amount of time (approximately 10 minutes) because the DTC may be stored after the air conditioning system operates for a while. HINT: When the outside air temperature is low (below -1.5°C (29.3°F)), the compressor stops due to operation of the ambient temperature sensor and the evaporator temperature sensor to prevent the evaporator from freezing. In this case, perform the inspection in a warm indoor environment. If refrigerant pressure is not normal after replacing the expansion valve with a normal one, the cooler condenser assembly or pipes may be clogged due to dirt, dust or other contaminants. In this case, clean or replace the cooler condenser assembly or pipes. OK DTC B1423 is not output. NG --> See step 24 OK --> END
19. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
20. REPLACE AIR CONDITIONER PRESSURE SENSOR. Refer to «REMOVAL»
21. CHARGE REFRIGERANT. Refer to «REPLACEMENT»
22. REPLACE CONDENSER FAN. Refer to «REMOVAL»
23. REPLACE COOLER DRYER. Refer to «REMOVAL»
24. REPLACE COOLER CONDENSER ASSEMBLY. Refer to «REMOVAL»

The automatic light control sensor (solar sensor), which is installed on the upper side of the instrument panel, detects sunlight and controls the air conditioning in auto mode. The output current from the solar sensor varies according to the amount of sunlight. When the sunlight increases, the output current increases. As the sunlight decreases, the output current decreases. The A/C amplifier detects output current from the solar sensor.

HINT

If DTC B1244 is output at the same time, troubleshoot DTC B1244 first.

Scheme 278

Scheme 279

Scheme 280

1. READ VALUE USING TECHSTREAM (DRIVER SIDE SOLAR SENSOR) Use the Data List to check if the driver side solar sensor is functioning properly. AIR CONDITIONER Tester Display Measurement Item/Range Normal Condition Diagnostic Note Solar Sensor (D Side) Driver side solar sensor / Min.: 0, Max.: 255 Driver side solar sensor voltage increases as brightness increases Open in the circuit: 0. Short in the circuit: 255. OK The display is as specified in the normal condition. NG --> See step 2 OK --> See step 5
2. CHECK HARNESS AND CONNECTOR (AUTOMATIC LIGHT CONTROL SENSOR - AIR CONDITIONING AMPLIFIER) Disconnect the F9 sensor connector. Disconnect the E35 amplifier connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition F9-1 (TSL) - E35-7 (TSD) Always Below 1 ohms E35-7 (TSD) - Body ground Always 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. INSPECT AUTOMATIC LIGHT CONTROL SENSOR (TSL - CLTE VOLTAGE) Remove the automatic light control sensor. Refer to «REMOVAL». Apply battery voltage to terminals 6 (CLTB) and 3 (CLTE) of the solar sensor. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Condition Specified Condition 1 (TSL) - 3 (CLTE) Sensor exposed to electric light 0.8 to 4.3 V Sensor covered with a cloth Below 0.8 V HINT: As the inspection light is moved away from the sensor, the voltage decreases. Use an incandescent light for inspection. Bring it about 300 mm (11.8 in.) from the solar sensor. NG --> See step 6 OK: Go to next step
4. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - AUTOMATIC LIGHT CONTROL SENSOR) Disconnect the E2 ECU connector. Disconnect the F9 sensor connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition E2-20 (CLTB) - F9-6 (CLTB) Always Below 1 ohms E2-19 (CLTS) - F9-5 (CLTS) E2-18 (CLTE) - F9-3 (CLTE) E2-20 (CLTB) - Body ground Always 10 kohms or higher E2-19 (CLTS) - Body ground E2-18 (CLTE) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> REPLACE MAIN BODY ECU (COWL SIDE JUNCTION BLOCK LH)
5. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
6. REPLACE AUTOMATIC LIGHT CONTROL SENSOR. Refer to «REMOVAL»

The duct sensor RH (for front passenger side) detects the duct temperature and sends the appropriate signals to the air conditioning amplifier assembly.

Scheme 281

Scheme 282

Scheme 283

1. READ VALUE USING TECHSTREAM (DUCT SENSOR RH) Use the Data List to check if the duct sensor RH (for front passenger side) is functioning properly. AIR CONDITIONER Tester Display Measurement Item/Range Normal Condition Diagnostic Note Foot Duct Sensor (Rear P) Duct sensor / Min.: -12.7°C (9.14°F) Max.: 76.55°C (169.79°F) Actual temperature measured by duct sensor RH displayed Open in the circuit: -12.7°C (9.14°F). Short in the circuit: 76.55°C (169.79°F). OK The display is as specified in the normal condition. NG --> See step 2 OK --> See step 4
2. CHECK DUCT SENSOR RH Remove the duct sensor RH. Refer to «REMOVAL». Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 1 (+) - 2 (-) 10°C (50°F) 9.4 to 10.5 kohms 15°C (59°F) 7.5 to 8.3 kohms 20°C (68°F) 6.0 to 6.5 kohms 25°C (77°F) 4.8 to 5.2 kohms 30°C (86°F) 3.8 to 4.2 kohms 35°C (95°F) 3.1 to 3.4 kohms 40°C (104°F) 2.5 to 2.8 kohms 45°C (113°F) 2.0 to 2.3 kohms 50°C (122°F) 1.6 to 2.0 kohms 55°C (131°F) 1.3 to 1.6 kohms 60°C (140°F) 1.1 to 1.4 kohms NOTE: Touching the sensor even slightly may change the resistance value. Hold the connector of the sensor. When measuring the resistance, the sensor temperature must be the same as the ambient temperature. HINT: As the temperature increases, the resistance decreases (See the graph). If the resistance value is not as specified, replace the sensor. NG --> See step 5 OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - DUCT SENSOR) Disconnect the L11 sensor connector. Disconnect the E35 amplifier connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition E35-26 (TR4) - L11-1 (+) Always Below 1 ohms E35-12 (SG-9) - L11-2 (-) E35-26 (TR4) - Body ground Always 10 kohms or higher E35-12 (SG-9) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 4
4. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
5. REPLACE DUCT SENSOR RH. Refer to «REMOVAL»

The front air mix damper servo motor (for front passenger side) sends pulse signals to inform the air conditioning amplifier assembly of the damper position. The air conditioning amplifier assembly activates the motor (normal or reverse) based on the signals to move the front air mix damper (for front passenger side) to any position. As a result, the amount of air that has passed through the evaporator and is passing through the heater core is adjusted, and the temperature of the air blowing toward the front passenger side is controlled.

HINT

Confirm that no mechanical problem is present because this trouble code can be stored when either a damper link or damper is mechanically locked.

Scheme 284

The REC/FRS damper servo motor sends pulse signals to inform the air conditioning amplifier assembly of the damper position. The air conditioning amplifier assembly activates the motor (normal or reverse) based on the signals to move the air inlet damper to any position, which controls the intake air settings (fresh, fresh/recirculation and recirculation).

HINT

Confirm that no mechanical problem is present because this trouble code can be stored when either a damper link or damper is mechanically locked.

Scheme 285

The air outlet damper servo motor (for driver side mode) sends pulse signals to inform the air conditioning amplifier assembly of the damper position. The air conditioning amplifier assembly activates the motor (normal or reverse) based on the signals to move the air outlet damper (for driver side mode) to any position, which controls the air outlet changes.

HINT

Confirm that no mechanical problem is present because this trouble code can be stored when either a damper link or damper is mechanically locked.

Scheme 286

The cool air bypass damper servo motor sends pulse signals to inform the air conditioning amplifier assembly of the damper position. The air conditioning amplifier assembly activates the motor (normal or reverse) based on the signals to move the cool air bypass damper to any position. As a result, when the air conditioner is operating, the temperature of the air blowing toward the head area is controlled.

HINT

Confirm that no mechanical problem is present because this trouble code can be stored when either a damper link or damper is mechanically locked.

Scheme 287

The front air mix damper servo motor (for driver side) sends pulse signals to inform the air conditioning amplifier assembly of the damper position. The air conditioning amplifier assembly activates the motor (normal or reverse) based on the signals to move the air mix damper (for driver side) to any position. As a result, the amount of air that has passed through the evaporator and is passing through the heater core is adjusted, and the temperature of the air blowing toward the driver side is controlled.

HINT

Confirm that no mechanical problem is present because this trouble code can be stored when either a damper link or damper is mechanically locked.

Scheme 288

The rear air mix damper servo motor LH sends pulse signals to indicate the damper position to the air conditioning amplifier assembly. The air conditioning amplifier assembly activates the motor (normal or reverse) based on these signals to move the rear air mix damper to the appropriate position. This adjusts the amount of air passing through the heater core after passing the evaporator and controls the temperature of the blown air.

HINT

Confirm that no mechanical problem is present because this trouble code can be stored when either a damper link or damper is mechanically locked.

Scheme 289

Scheme 290

1. READ VALUE USING TECHSTREAM (REAR AIR MIX DAMPER SERVO MOTOR LH) Use the Data List to check if the servo motor is functioning properly. AIR CONDITIONER Tester Display Measurement Item/Range Normal Condition Diagnostic Note A/M Servo Targ Pulse (Rear D) Rear air mix damper servo motor LH target pulse / Min.: 9, Max.: 54 MAX COOL: 9 (pulse) MAX HOT: 54 (pulse) - OK The display is as specified in the normal condition. NG --> See step 2 OK --> See step 5
2. CHECK HARNESS AND CONNECTOR (NO. 2 AIR CONDITIONING HARNESS - AIR CONDITIONING AMPLIFIER) Disconnect the K19 No. 2 air conditioning harness assembly connector. Disconnect the E36 amplifier connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition K19-2 (RBUG) - E36-12 (RBUG) Always Below 1 ohms K19-3 (RBUS) - E36-13 (RBUS) K19-4 (RBBU) - E36-14 (RBBU) E36-12 (RBUG) - Body ground Always 10 kohms or higher E36-13 (RBUS) - Body ground E36-14 (RBBU) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. REPLACE REAR AIR MIX DAMPER SERVO MOTOR LH Replace the air mix damper servo motor LH. Refer to «DISASSEMBLY». HINT: Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a normal one. NEXT: Go to next step
4. CHECK FOR DTC Clear the DTCs. Refer to «DTC CHECK / CLEAR». Check for DTCs. Refer to «DTC CHECK / CLEAR». OK DTC B1447 is not output. NG --> See step 6 OK --> See step 7
5. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
6. REPLACE NO. 2 AIR CONDITIONING HARNESS ASSEMBLY. Refer to «DISASSEMBLY»
7. REPLACE REAR AIR MIX DAMPER SERVO MOTOR LH. Refer to «DISASSEMBLY»

The air outlet damper servo motor (for front passenger side mode) sends pulse signals to inform the air conditioning amplifier assembly of the damper position. The air conditioning amplifier assembly activates the motor (normal or reverse) based on the signals to move the air outlet damper (for front passenger side mode) to any position, which controls the air outlet changes.

HINT

Confirm that no mechanical problem is present because this trouble code can be stored when either a damper link or damper is mechanically locked.

Scheme 291

The rear air outlet damper servo motor sends pulse signals to inform the air conditioning amplifier assembly of the damper position. The air conditioning amplifier assembly activates the motor (normal or reverse) based on the signals to move the rear air outlet damper to the appropriate position, which controls the air outlet modes.

HINT

Confirm that no mechanical problem is present because this trouble code can be stored when either a damper link or damper is mechanically locked.

Scheme 292

Scheme 293

1. READ VALUE USING TECHSTREAM (REAR AIR OUTLET DAMPER SERVO MOTOR) Use the Data List to check if the servo motor is functioning properly. AIR CONDITIONER Tester Display Measurement Item/Range Normal Condition Diagnostic Note Air Outlet Servo Pulse (R) Rear air outlet damper servo motor target pulse / Min.: 7, Max.: 83 FOOT: 7 (pulse) B/L: 42 (pulse) FACE: 83 (pulse) - OK The display is as specified in the normal condition. NG --> See step 2 OK --> See step 6
2. CHECK HARNESS AND CONNECTOR (NO. 2 AIR CONDITIONING HARNESS - AIR CONDITIONING AMPLIFIER) Disconnect the K19 No. 2 air conditioning harness assembly connector. Disconnect the E36 amplifier connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition K19-2 (RBUG) - E36-12 (RBUG) Always Below 1 ohms K19-3 (RBUS) - E36-13 (RBUS) K19-4 (RBBU) - E36-14 (RBBU) E36-12 (RBUG) - Body ground Always 10 kohms or higher E36-13 (RBUS) - Body ground E36-14 (RBBU) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. REPLACE REAR AIR OUTLET DAMPER SERVO MOTOR Replace the rear air outlet damper servo motor. Refer to «DISASSEMBLY». HINT: Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a normal one. NEXT: Go to next step
4. CHECK FOR DTC Clear the DTCs. Refer to «DTC CHECK / CLEAR». Check for DTCs. Refer to «DTC CHECK / CLEAR». OK DTC B1449 is not output. NG --> See step 7 OK --> See step 5
5. REPLACE REAR AIR OUTLET DAMPER SERVO MOTOR. Refer to «DISASSEMBLY»
6. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
7. REPLACE NO. 2 AIR CONDITIONING HARNESS ASSEMBLY. Refer to «DISASSEMBLY»

The front air mix damper servo motor (for driver side rear air flow) sends pulse signals to inform the air conditioning amplifier assembly of the damper position. The air conditioning amplifier assembly activates the motor (normal or reverse) based on the signals to move the front air mix damper (for driver side rear air flow) to any position. As a result, the amount of air that has passed through the evaporator and is passing through the heater core is adjusted, and the temperature of the air blowing toward the rear driver side is controlled.

HINT

Confirm that no mechanical problem is present because this trouble code can be stored when either a damper link or damper is mechanically locked.

Scheme 294

The front air mix damper servo motor (for front passenger side rear air flow) sends pulse signals to inform the air conditioning amplifier assembly of the damper position. The air conditioning amplifier assembly activates the motor (normal or reverse) based on the signals to move the front air mix damper (for front passenger side rear air flow) to any position. As a result, the amount of air that has passed through the evaporator and is passing through the heater core is adjusted, and the temperature of the air blowing toward the rear passenger side is controlled.

HINT

Confirm that no mechanical problem is present because this trouble code can be stored when either a damper link or damper is mechanically locked.

Scheme 295

The smog ventilation sensor, which is installed on the front of the cooler condenser assembly, automatically changes to fresh, fresh/recirculation or recirculation mode operation. The smog ventilation sensor detects NOx in the emission gas and transmits signals to the air conditioning amplifier assembly.

Scheme 296

Scheme 297

1. INSPECT FUSE (A/C IG) Remove the A/C IG fuse from the cowl side junction block LH. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A/C IG fuse Always Below 1 ohms NG --> REPLACE FUSE OK: Go to next step
2. READ VALUE USING TECHSTREAM (SMOG VENTILATION SENSOR) Use the Data List to check if the smog ventilation sensor is functioning properly. AIR CONDITIONER Tester Display Measurement Item / Range Normal Condition Diagnostic Note Emission Gas Nox Sensor Smog ventilation sensor/ Min.: 0, Max.: 255 Increases as the gas amount increases - OK The display is as specified in the normal condition. NG --> See step 3 OK --> See step 8
3. CHECK HARNESS AND CONNECTOR (SMOG VENTILATION SENSOR - BODY GROUND) Disconnect the A45 smog ventilation sensor connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Switch Condition Specified Condition A45-6 (E) - Body ground Always Below 1 ohms NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK HARNESS AND CONNECTOR (SMOG VENTILATION SENSOR - BATTERY) Disconnect the A45 smog ventilation sensor connector. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Condition Specified Condition A45-3 (IG) - Body ground Engine switch on (IG) 11 to 14 V NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
5. INSPECT SMOG VENTILATION SENSOR Remove the smog ventilation sensor. Refer to «REMOVAL». After applying battery voltage to terminals 3 (IG) and 6 (E) for more than 30 seconds, measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 1 (SG) - 4 (DGS1) 15 to 25°C (59 to 77°F) 2.5 to 40 kohms HINT: When the sensor is exposed to the exhaust gas, the resistance increases. NG --> See step 9 OK: Go to next step
6. CHECK HARNESS AND CONNECTOR (SMOG VENTILATION SENSOR - AIR CONDITIONING AMPLIFIER) Disconnect the A45 smog ventilation sensor connector. Disconnect the E35 amplifier connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A45-1 (SG) - E35-30 (SG-4) Always Below 1 ohms A45-4 (DGS1) - E35-24 (DGS1) E35-24 (DGS1) - Body ground Always 10 kohms or higher E35-30 (SG-4) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 7
7. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
8. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
9. REPLACE SMOG VENTILATION SENSOR. Refer to «REMOVAL»

The duct sensor LH (for driver side) detects the duct temperature and sends the appropriate signals to the air conditioning amplifier assembly.

Scheme 298

Scheme 299

Scheme 300

1. READ VALUE USING TECHSTREAM (DUCT SENSOR LH) Use the Data List to check if the duct sensor LH (for driver side) is functioning properly. AIR CONDITIONER Tester Display Measurement Item/Range Normal Condition Diagnostic Note Foot Duct Sensor (Rear D) Duct sensor / Min.: -12.7°C (9.14°F) Max.: 76.55°C (169.79°F) Actual temperature measured by duct sensor LH displayed Open in the circuit: -12.7°C (9.14°F). Short in the circuit: 76.55°C (169.79°F). OK The display is as specified in the normal condition. NG --> See step 2 OK --> See step 4
2. CHECK DUCT SENSOR LH Remove the duct sensor LH. Refer to «REMOVAL». Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 1 (+) - 2 (-) 10°C (50°F) 9.4 to 10.5 kohms 15°C (59°F) 7.5 to 8.3 kohms 20°C (68°F) 6.0 to 6.5 kohms 25°C (77°F) 4.8 to 5.2 kohms 30°C (86°F) 3.8 to 4.2 kohms 35°C (95°F) 3.1 to 3.4 kohms 40°C (104°F) 2.5 to 2.8 kohms 45°C (113°F) 2.0 to 2.3 kohms 50°C (122°F) 1.6 to 2.0 kohms 55°C (131°F) 1.3 to 1.6 kohms 60°C (140°F) 1.1 to 1.4 kohms NOTE: Touching the sensor even slightly may change the resistance value. Hold the connector of the sensor. When measuring the resistance, the sensor temperature must be the same as the ambient temperature. HINT: As the temperature increases, the resistance decreases (See the graph). If the resistance value is not as specified, replace the sensor. NG --> See step 5 OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - DUCT SENSOR) Disconnect the K21 sensor connector. Disconnect the E35 amplifier connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition E35-25 (TR3) - K21-1 (+) Always Below 1 ohms E35-34 (SGND) - K21-2 (-) E35-25 (TR3) - Body ground Always 10 kohms or higher E35-34 (SGND) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 4
4. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
5. REPLACE DUCT SENSOR LH. Refer to «REMOVAL»

The rear room temperature sensor RH is installed in the rear quarter trim board RH to detect the rear room temperature and control the heater and air conditioner auto mode. The resistance of the rear room temperature sensor RH changes in accordance with the rear room temperature for RH seat. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.

The air conditioning amplifier assembly applies a voltage (5 V) to the rear room temperature sensor RH and reads voltage changes as changes in the resistance of the rear room temperature sensor RH.

Scheme 301

Scheme 302

Scheme 303

1. READ VALUE USING TECHSTREAM (REAR ROOM TEMPERATURE SENSOR RH) Use the Data List to check if the rear room temperature sensor RH is functioning properly. AIR CONDITIONER Tester Display Measurement Item/Range Normal Condition Diagnostic Note Room Temperature Sensor (RP) Rear room temperature sensor RH / Min.: -6.5°C (20.3°F) Max.: 57.25°C (135.05°F) Actual rear room temperature for RH seat displayed Open in the circuit: -6.5°C (20.3°F). Short in the circuit: 57.25°C (135.05°F). OK The display is as specified in the normal condition. NG --> See step 2 OK --> See step 5
2. INSPECT REAR ROOM TEMPERATURE SENSOR RH Remove the rear room temperature sensor RH. Refer to «REMOVAL». Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 1 (+) - 2 (-) 10°C (50°F) 3.00 to 3.73 kohms 15°C (59°F) 2.45 to 2.88 kohms 20°C (68°F) 1.95 to 2.30 kohms 25°C (77°F) 1.60 to 1.80 kohms 30°C (86°F) 1.28 to 1.47 kohms 35°C (95°F) 1.00 to 1.22 kohms 40°C (104°F) 0.80 to 1.00 kohms 45°C (113°F) 0.65 to 0.85 kohms 50°C (122°F) 0.50 to 0.70 kohms 55°C (131°F) 0.44 to 0.60 kohms 60°C (140°F) 0.36 to 0.50 kohms NOTE: Even slightly touching the sensor may change the resistance value. Be sure to hold the connector of the sensor. HINT: As the temperature increases, the resistance decreases (See the graph). NG --> See step 6 OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (REAR ROOM TEMPERATURE SENSOR RH - AIR CONDITIONING AMPLIFIER) Disconnect the Z37 sensor connector. Disconnect the E35 amplifier connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition Z37-2 (-) - E35-2 (SG-6) Always Below 1 ohms Z37-1 (+) - E35-19 (TR7) E35-19 (TR7) - Body ground Always 10 kohms or higher E35-2 (SG-6) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 4
4. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
5. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
6. REPLACE REAR ROOM TEMPERATURE SENSOR RH. Refer to «REMOVAL»

The air outlet damper servo motor (for rear seat mode) sends pulse signals to inform the air conditioning amplifier assembly of the damper position. The air conditioning amplifier assembly activates the motor (normal or reverse) based on the signals to move the air outlet damper to any position, which controls the air outlet changes.

HINT

Confirm that no mechanical problem is present because this trouble code can be stored when either a damper link or damper is mechanically locked.

Scheme 304

The rear air mix damper servo motor RH sends pulse signals to indicate the damper position to the air conditioning amplifier assembly. The air conditioning amplifier assembly activates the motor (normal or reverse) based on these signals to move the rear air mix damper to the appropriate position. This adjusts the amount of air passing through the heater core after passing the evaporator and controls the temperature of the blown air.

HINT

Confirm that no mechanical problem is present because this trouble code can be stored when either a damper link or damper is mechanically locked.

Scheme 305

Scheme 306

1. READ VALUE USING TECHSTREAM (REAR AIR MIX DAMPER SERVO MOTOR RH) Use the Data List to check if the servo motor is functioning properly. AIR CONDITIONER Tester Display Measurement Item/Range Normal Condition Diagnostic Note A/M Servo Targ Pulse (Rear P) Rear air mix damper servo motor RH target pulse / Min.: 8, Max.: 53 MAX COOL: 53 (pulse) MAX HOT: 8 (pulse) - OK The display is as specified in the normal condition. NG --> See step 2 OK --> See step 6
2. CHECK HARNESS AND CONNECTOR (NO. 2 AIR CONDITIONING HARNESS - AIR CONDITIONING AMPLIFIER) Disconnect the K19 No. 2 air conditioning harness assembly connector. Disconnect the E36 amplifier connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition K19-2 (RBUG) - E36-12 (RBUG) Always Below 1 ohms K19-3 (RBUS) - E36-13 (RBUS) K19-4 (RBBU) - E36-14 (RBBU) E36-12 (RBUG) - Body ground Always 10 kohms or higher E36-13 (RBUS) - Body ground E36-14 (RBBU) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. REPLACE REAR AIR MIX DAMPER SERVO MOTOR RH Replace the rear air mix damper servo motor RH. Refer to «DISASSEMBLY». HINT: Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a normal one. NEXT: Go to next step
4. CHECK FOR DTC Clear the DTCs. Refer to «DTC CHECK / CLEAR». Check for DTCs. Refer to «DTC CHECK / CLEAR». OK DTC B1489 is not output. NG --> See step 7 OK --> See step 5
5. REPLACE REAR AIR MIX DAMPER SERVO MOTOR RH. Refer to «DISASSEMBLY»
6. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
7. REPLACE NO. 2 AIR CONDITIONING HARNESS ASSEMBLY. Refer to «DISASSEMBLY»

The air conditioning harness assembly connects the air conditioning amplifier assembly and each servo motor. The air conditioning amplifier assembly supplies power and sends operation instructions to each servo motor through the air conditioning harness assembly. Each servo motor sends the damper position information to the air conditioning amplifier assembly.

Scheme 307

Scheme 308

1. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY Remove the air conditioning amplifier assembly with its connectors still connected. Refer to «REMOVAL». Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition z45-1 (BUS G) - Body ground Always Below 1 ohms z45-8 (BUS G) - Body ground Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition z45-1 (BUS G) - z45-3 (B BUS) Always 11 to 14 V z45-8 (BUS G) - z45-10 (B BUS) z45-1 (BUS G) - z45-2 (BUS) Engine switch on (IG) Pulse generation z45-8 (BUS G) - z45-9 (BUS) NG --> See step 3 OK --> See step 2
2. REPLACE AIR CONDITIONING HARNESS ASSEMBLY. Refer to «DISASSEMBLY»
3. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»

The air conditioning amplifier assembly communicates with the ECM and meter ECU through the CAN communication system.

Scheme 309

The cooler expansion valve (cooler magnetic valve) is controlled by the air conditioning amplifier assembly (for cool box).

Scheme 310

Scheme 311

Scheme 312

1. INSPECT FUSE (A/C IG) Remove the A/C IG fuse from the cowl side junction block LH. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A/C IG fuse Always Below 1 ohms NG --> REPLACE FUSE OK: Go to next step
2. CHECK HARNESS AND CONNECTOR (NO. 1 COOLER WIRING HARNESS - BATTERY) Disconnect the No. 1 cooler wiring harness sub-assembly connector. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition 1 (B) - Body ground Engine switch off Below 1 V Engine switch on (IG) 11 to 14 V NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (NO. 1 COOLER WIRING HARNESS - BODY GROUND) Disconnect the No. 1 cooler wiring harness sub-assembly connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 6 (L) - Body ground Always Below 1 ohms NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK NO. 1 COOLER WIRING HARNESS SUB-ASSEMBLY (OPERATION) Replace the No. 1 cooler wiring harness sub-assembly with a normal one and check that the condition returns to normal. OK Same problem does not occur. NG --> See step 5 OK --> REPLACE NO. 1 COOLER WIRING HARNESS SUB-ASSEMBLY
5. CHECK COOLER MAGNETIC VALVE (OPERATION) Replace the cooler magnetic valve. Refer to «DISASSEMBLY». HINT: Since the cooler magnetic valve cannot be inspected while it is removed from the vehicle, replace the cooler magnetic valve with a normal one and check that the condition returns to normal. OK Same problem does not occur. NG --> See step 6 OK --> See step 7
6. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY (for Cool Box). Refer to «DISASSEMBLY»
7. REPLACE COOLER MAGNETIC VALVE. Refer to «DISASSEMBLY»

The cooler blower motor is operated by signals from the air conditioning amplifier assembly (for cool box).

Scheme 313

Scheme 314

Scheme 315

1. INSPECT FUSE (A/C IG) Remove the A/C IG fuse from the cowl side junction block LH. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A/C IG fuse Always Below 1 ohms NG --> REPLACE FUSE OK: Go to next step
2. CHECK HARNESS AND CONNECTOR (NO. 1 COOLER WIRING HARNESS - BATTERY) Disconnect the No. 1 cooler wiring harness sub-assembly connector. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition 1 (B) - Body ground Engine switch off Below 1 V Engine switch on (IG) 11 to 14 V NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (NO. 1 COOLER WIRING HARNESS - BODY GROUND) Disconnect the No. 1 cooler wiring harness sub-assembly connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 6 (L) - Body ground Always Below 1 ohms NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK NO. 1 COOLER WIRING HARNESS SUB-ASSEMBLY (OPERATION) Replace the No. 1 cooler wiring harness sub-assembly with a normal one and check that the condition returns to normal. OK Same problem does not occur. NG --> See step 5 OK --> REPLACE NO. 1 COOLER WIRING HARNESS SUB-ASSEMBLY
5. INSPECT COOLER BLOWER MOTOR Remove the cooler blower motor. Refer to «DISASSEMBLY». Connect the positive (+) lead from the battery to terminal 2 and negative (-) lead to terminal 1, then check that the motor operates smoothly. OK Cooler blower motor operates smoothly. NG --> See step 6 OK --> See step 7
6. REPLACE COOLER BLOWER MOTOR. Refer to «DISASSEMBLY»
7. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY (for Cool Box). Refer to «DISASSEMBLY»

The cooler control switch sub-assembly is the activation switch for the cool box. If the cool box does not activate when the cooler control switch sub-assembly is pushed, there may be a malfunction in the circuit shown below.

Scheme 316

Scheme 317

Scheme 318

1. INSPECT FUSE (PANEL, A/C IG, ECU-B1) Remove the PANEL and A/C IG fuses from the cowl side junction block LH. Remove the ECU-B1 fuse from the engine room relay block. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition PANEL fuse Always Below 1 ohms ECU-B1 fuse Always Below 1 ohms A/C IG fuse Always Below 1 ohms NG --> REPLACE FUSE OK: Go to next step
2. CHECK HARNESS AND CONNECTOR (NO. 1 COOLER WIRING HARNESS - BATTERY) Disconnect the No. 1 cooler wiring harness sub-assembly connector. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition 4 (+B) - Body ground Always 11 to 14 V 3 - Body ground Engine switch off Below 1 V Engine switch on (IG) 11 to 14 V 1 (B) - Body ground Engine switch off Below 1 V Engine switch on (IG) 11 to 14 V NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (NO. 1 COOLER WIRING HARNESS - BODY GROUND) Disconnect the No. 1 cooler wiring harness sub-assembly connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 6 (L) - Body ground Always Below 1 ohms NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK NO. 1 COOLER WIRING HARNESS SUB-ASSEMBLY (OPERATION) Replace the No. 1 cooler wiring harness sub-assembly with a normal one and check that the condition returns to normal. OK Same problem does not occur. NG --> See step 5 OK --> REPLACE NO. 1 COOLER WIRING HARNESS SUB-ASSEMBLY
5. INSPECT COOLER CONTROL SWITCH SUB-ASSEMBLY Remove the cooler control switch sub-assembly. Refer to «DISASSEMBLY». Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Switch Condition Specified Condition 1 - 2 On Below 1 ohms 1 - 2 Off 10 kohms or higher Apply battery voltage to the cooler control switch connector and check that the cooler control switch illuminates. OK Measurement Condition Specified Condition Battery positive (+) --> Terminal 3 Battery negative (-) --> Terminal 4 LED illuminates Battery positive (+) --> Terminal 5 Battery negative (-) --> Terminal 6 LED illuminates NG --> See step 6 OK --> See step 7
6. REPLACE COOLER CONTROL SWITCH SUB-ASSEMBLY. Refer to «DISASSEMBLY»
7. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY (for Cool Box). Refer to «DISASSEMBLY»

The No. 3 cooler thermistor is installed on the evaporator in the cooling box unit to detect the cooled air temperature that has passed through the evaporator and control the cooling box. It sends appropriate signals to the air conditioning amplifier assembly (for cool box). The resistance of the No. 3 cooler thermistor changes in accordance with the cooled air temperature that has passed through the evaporator. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.

The air conditioning amplifier assembly (for cool box) applies voltage (12 V) to the No. 3 cooler thermistor and reads voltage changes as the resistance of the No. 3 cooler thermistor changes.

Scheme 319

Scheme 320

1. INSPECT FUSE (A/C IG, ECU-B1) Remove the A/C IG fuse from the cowl side junction block LH. Remove the ECU-B1 fuse from the engine room relay block. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition ECU-B1 fuse Always Below 1 ohms A/C IG fuse NG --> REPLACE FUSE OK: Go to next step
2. CHECK HARNESS AND CONNECTOR (NO. 1 COOLER WIRING HARNESS - BATTERY) Disconnect the No. 1 cooler wiring harness sub-assembly connector. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition 4 (+B) - Body ground Always 11 to 14 V 1 (B) - Body ground Engine switch off Below 1 V Engine switch on (IG) 11 to 14 V NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (NO. 1 COOLER WIRING HARNESS - BODY GROUND) Disconnect the No. 1 cooler wiring harness sub-assembly connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 6 (L) - Body ground Always Below 1 ohms NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK NO. 1 COOLER WIRING HARNESS SUB-ASSEMBLY (OPERATION) Replace the No. 1 cooler wiring harness sub-assembly with a normal one and check that the condition returns to normal. OK Same problem does not occur. NG --> See step 5 OK --> REPLACE NO. 1 COOLER WIRING HARNESS SUB-ASSEMBLY
5. CHECK NO. 3 COOLER THERMISTOR Remove the No. 3 cooler thermistor. Refer to «DISASSEMBLY». Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 1 (+) - 2 (-) -10°C (14°F) 7.30 to 9.10 kohms -5°C (23°F) 5.65 to 6.95 kohms 0°C (32°F) 4.40 to 5.35 kohms 5°C (41°F) 3.40 to 4.15 kohms 10°C (50°F) 2.70 to 3.25 kohms 15°C (59°F) 2.14 to 2.58 kohms 20°C (68°F) 1.71 to 2.05 kohms 25°C (77°F) 1.38 to 1.64 kohms 30°C (86°F) 1.11 to 1.32 kohms NOTE: Even slightly touching the sensor may change the resistance value. Be sure to hold the connector of the sensor. When measuring, the sensor temperature must be the same as the ambient temperature. HINT: As the temperature increases, the resistance decreases (See the graph). NG --> See step 6 OK --> See step 7
6. REPLACE NO. 3 COOLER THERMISTOR. Refer to «DISASSEMBLY»
7. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY (for Cool Box). Refer to «DISASSEMBLY»

Scheme 321

The blower motor sub-assembly (with fan) is operated by signals from the air conditioning amplifier assembly. The blower motor sub-assembly (with fan) speed signals are transmitted by changes in the duty ratio.

Duty Ratio

The duty ratio is the ratio of the blower motor sub-assembly (with fan) OPEN time (T1) to the total of the blower motor sub-assembly (with fan) OPEN and LO time (T2).

The air conditioning amplifier assembly controls the blower motor sub-assembly (with fan) speed.

Scheme 322

Scheme 323

Scheme 324

Scheme 325

Scheme 326

Scheme 327

1. PERFORM ACTIVE TEST USING TECHSTREAM (BLOWER MOTOR SUB-ASSEMBLY) Select the Active Test, use the Techstream to generate a control command, and then check that the blower motor operates. AIR CONDITIONER Tester Display Test Part Control Range Diagnostic Note Blower Motor Blower motor sub-assembly (with fan) Min.: 0, Max.: 31 - RESULT Result Proceed to Blower motor operates normally A Blower motor does not operate B Blower motor operates but does not change speed C C --> See step 6 B --> See step 2 A --> See step 9
2. CHECK HARNESS AND CONNECTOR (BLOWER MOTOR - BODY GROUND) Disconnect the A29 motor connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A29-1 (GND) - Body ground Always Below 1 ohms NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (BLOWER MOTOR - BATTERY) Disconnect the A29 motor connector. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Condition Specified Condition A29-3 (+B) - Body ground Always 11 to 14 V NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK BLOWER MOTOR SUB-ASSEMBLY (SI VOLTAGE) Disconnect the E36 amplifier connector. Reconnect the A29 motor connector. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition A29-2 (SI) - Body ground Engine switch on (IG) 4.5 to 5.5 V NG --> See step 8 OK: Go to next step
5. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BLOWER MOTOR) Disconnect the E36 amplifier connector. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition E36-3 (BLW) - E36-1 (GND) Engine switch on (IG) Blower switch off 4.5 to 5.5 V NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 10
6. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BLOWER MOTOR) Disconnect the E36 amplifier connector. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition E36-3 (BLW) - E36-1 (GND) Engine switch on (IG) Blower switch off 4.5 to 5.5 V NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
7. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY (BLW SIGNAL) Remove the air conditioning amplifier assembly with its connectors still connected. Refer to «REMOVAL». Using an oscilloscope, check the waveform. MEASUREMENT CONDITION Item Content Terminal No. (Symbol) E36-3 (BLW) - E36-1 (GND) Tool Setting 1 V/DIV., 500 μs/DIV. Condition Engine switch on (IG) Blower switch off --> on OK Waveform is as shown in the illustration. HINT: Waveform varies with the blower level. NG --> See step 10 OK --> See step 8
8. REPLACE BLOWER MOTOR SUB-ASSEMBLY. Refer to «DISASSEMBLY»
9. PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to «PROBLEM SYMPTOMS TABLE»
10. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»

When the air conditioning amplifier assembly is turned on, a magnetic clutch on signal is sent from the MGC terminal of the air conditioning amplifier assembly. Then, the magnetic clutch relay turns on to operate the magnetic clutch.

Scheme 328

Scheme 329

Scheme 330

Scheme 331

Scheme 332

Scheme 333

Scheme 334

1. CHECK CAN COMMUNICATION SYSTEM Check for CAN communication system DTCs related to the air conditioning system. RESULT Result Proceed to CAN DTC is not output A CAN DTC is output B B --> See step 10 A: Go to next step
2. READ VALUE USING TECHSTREAM (A/C SIGNAL) Use the Data List to check if the A/C switch is functioning properly. ENGINE Tester Display Measurement Item/Range Normal Condition Diagnostic Note A/C Signal A/C switch signal / ON or OFF ON: A/C switch on OFF: A/C switch off - OK The display is as specified in the normal condition. NG --> See step 3 OK --> See step 11
3. INSPECT FUSE (A/C IG) Remove the A/C IG fuse from the cowl side junction block LH. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A/C IG fuse Always Below 1 ohms NG --> REPLACE FUSE OK: Go to next step
4. INSPECT MAGNETIC CLUTCH RELAY Remove the magnetic clutch relay from the engine room relay block. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 3 - 5 Battery voltage not applied to terminals 1 and 2 10 kohms or higher 3 - 5 Battery voltage applied to terminals 1 and 2 Below 1 ohms NG --> REPLACE MAGNETIC CLUTCH RELAY OK: Go to next step
5. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BATTERY) Disconnect the E36 amplifier connector. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition E36-18 (MGC) - Body ground Engine switch off Below 1 V E36-18 (MGC) - Body ground Engine switch on (IG) 11 to 14 V NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
6. INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY Reconnect the E36 amplifier connector. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition E36-18 (MGC) - Body ground Engine switch on (IG) A/C switch off 11 to 14 V E36-18 (MGC) - Body ground Engine switch on (IG) A/C switch on Below 1 V NG --> See step 12 OK: Go to next step
7. INSPECT COOLER COMPRESSOR ASSEMBLY Disconnect the C37 compressor connector. Disconnect the A magnetic clutch connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition C37-3 (MG+) - A-1 Always Below 1 ohms C37-3 (MG+) - Body ground Always 10 kohms or higher NG --> See step 13 OK: Go to next step
8. INSPECT MAGNETIC CLUTCH Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A-1 - Body ground 20°C (68°F) 3.4 to 3.8 ohms When connector terminal A-1 is connected to the positive (+) battery terminal, check that the following occurs: 1) the operating sound of the magnetic clutch can be heard, and 2) the hub and rotor of the magnetic clutch lock. NG --> REPLACE MAGNETIC CLUTCH OK: Go to next step
9. CHECK HARNESS AND CONNECTOR (ENGINE ROOM RELAY BLOCK - BATTERY) Remove the magnetic clutch relay from the engine room relay block. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition Relay block magnetic clutch relay terminal 5 - Body ground Engine switch on (IG) 11 to 14 V Relay block magnetic clutch relay terminal 1 - Body ground Engine switch on (IG) 11 to 14 V NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE ROOM RELAY BLOCK - BATTERY) OK --> REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE ROOM RELAY BLOCK - COOLER COMPRESSOR ASSEMBLY)
10. GO TO CAN COMMUNICATION SYSTEM. Refer to «HOW TO PROCEED WITH TROUBLESHOOTING»
11. REPLACE ECM. Refer to «REMOVAL»
12. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
13. REPLACE COOLER COMPRESSOR ASSEMBLY. Refer to «REMOVAL»

This circuit consists of the No. 2 air conditioning control assembly and the air conditioning amplifier assembly. When the No. 2 air conditioning control assembly is operated, signals are transmitted to the air conditioning amplifier assembly through the LIN communication system.

If the LIN communication system malfunctions, the air conditioning amplifier assembly does not operate even if the No. 2 air conditioning control assembly is operated.

Scheme 335

Scheme 336

Scheme 337

1. INSPECT FUSE (ECU-IG NO. 2) Remove the ECU-IG NO. 2 fuse from the cowl side junction block LH. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition ECU-IG NO. 2 fuse Always Below 1 ohms NG --> REPLACE FUSE OK: Go to next step
2. CHECK HARNESS AND CONNECTOR (NO. 2 AIR CONDITIONING CONTROL - BODY GROUND AND BATTERY) Disconnect the E55 No. 2 air conditioning control assembly connector. Measure the resistance and voltage according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition E55-1 (E) - Body ground Always Below 1 ohms Standard Voltage Tester Connection Switch Condition Specified Condition E55-6 (IG) - Body ground Engine switch on (IG) 11 to 14 V NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - NO. 2 AIR CONDITIONING CONTROL) Disconnect the E55 No. 2 air conditioning control assembly connector. Disconnect the E36 amplifier connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition E36-21 (RLIN) - E55-4 (RLIN) Always Below 1 ohms E55-4 (RLIN) - Body ground Always 10 kohms or higher E36-21 (RLIN) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK NO. 2 AIR CONDITIONING CONTROL ASSEMBLY (OPERATION) Replace the No. 2 air conditioning control assembly with a new or properly functioning one. Refer to «REMOVAL». Operate the No. 2 air conditioning control assembly to check that it functions properly. OK No. 2 air conditioning control assembly function operates normally. NG --> See step 6 OK --> See step 5
5. REPLACE NO. 2 AIR CONDITIONING CONTROL ASSEMBLY. Refer to «REMOVAL»
6. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»

PTC heater relays are closed in accordance with signals from the air conditioning amplifier assembly and power is supplied to the quick heater assembly installed on the radiator heater unit.

Scheme 338

Scheme 339

Scheme 340

Scheme 341

Scheme 342

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Scheme 346

1. INSPECT PTC HEATER RELAY (PTC HTR1) Remove the PTC HTR1 relay from the engine room relay block. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 3 - 5 Battery voltage is not applied between terminals 1 and 2 10 kohms or higher Battery voltage is applied to terminals 1 and 2 Below 1 ohms NG --> REPLACE PTC HEATER RELAY OK: Go to next step
2. INSPECT PTC HEATER RELAY (PTC HTR2) Remove the PTC HTR2 relay from the engine room relay block. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 3 - 5 Battery voltage is not applied between terminals 1 and 2 10 kohms or higher Battery voltage is applied to terminals 1 and 2 Below 1 ohms NG --> REPLACE PTC HEATER RELAY OK: Go to next step
3. INSPECT PTC HEATER RELAY (PTC HTR3) Remove the PTC HTR3 relay from the engine room relay block. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 3 - 5 Battery voltage is not applied between terminals 1 and 2 10 kohms or higher Battery voltage is applied to terminals 1 and 2 Below 1 ohms NG --> REPLACE PTC HEATER RELAY OK: Go to next step
4. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY Remove the air conditioning amplifier assembly with its connectors still connected. Refer to «REMOVAL». Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Condition Specified Condition E36-27 (PTC1) - Body ground Engine switch on (IG) Temperature setting: Hi Outside temperature: 10°C (50°F) or less Engine coolant temperature: 73°C (163.4°F) or less Blower switch on 11 to 14 V E36-26 (PTC2) - Body ground E36-35 (PTC3) - Body ground NG --> See step 8 OK: Go to next step
5. CHECK HARNESS AND CONNECTOR (PTC HEATER RELAY - QUICK HEATER) Remove the PTC heater relays from the engine room relay block. Disconnect the E33 quick heater assembly connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition PTC HTR2 terminal 3 - E33-1 (B) Always Below 1 ohms PTC HTR1 terminal 3 - E33-2 (B) PTC HTR3 terminal 3 - E33-3 (B) PTC HTR2 terminal 3 - Body ground Always 10 kohms or higher PTC HTR1 terminal 3 - Body ground PTC HTR3 terminal 3 - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
6. INSPECT QUICK HEATER ASSEMBLY Disconnect the E33 and E34 quick heater assembly connectors. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition E33-1 (B) - E34-1 (E) Always Below 1 kohms E33-2 (B) - E34-1 (E) E33-3 (B) - E34-2 (E) NG --> See step 9 OK: Go to next step
7. CHECK HARNESS AND CONNECTOR (QUICK HEATER - BODY GROUND) Disconnect the E34 quick heater assembly connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition E34-1 (E) - Body ground Always Below 1 ohms E34-2 (E) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
8. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BODY GROUND) Disconnect the E36 amplifier connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition E36-27 (PTC1) - Body ground Always Below 200 ohms E36-26 (PTC2) - Body ground E36-35 (PTC3) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 10
9. REPLACE QUICK HEATER ASSEMBLY. Refer to «REMOVAL»
10. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»

Scheme 347

The rear blower motor sub-assembly (with fan) is operated by signals from the air conditioning amplifier assembly. The rear blower motor sub-assembly (with fan) speed signals are transmitted by changes in the duty ratio.

Duty Ratio

The duty ratio is the ratio of the rear blower motor sub-assembly (with fan) OPEN time (T1) to the total of the rear blower motor sub-assembly (with fan) OPEN and LO time (T2).

The blower motor controller controls the rear blower motor sub-assembly (with fan) speed.

Scheme 348

Scheme 349

Scheme 350

Scheme 351

Scheme 352

Scheme 353

Scheme 354

1. PERFORM ACTIVE TEST USING TECHSTREAM (REAR BLOWER MOTOR SUB-ASSEMBLY) Select the Active Test, use the Techstream to generate a control command, and then check that the rear blower motor operates. AIR CONDITIONER Tester Display Test Part Control Range Diagnostic Note Rear Blower Motor Rear blower motor sub-assembly (with fan) Min.: 0, Max.: 31 - RESULT Result Proceed to Rear blower motor operates normally A Rear blower motor does not operate B Rear blower motor operates but does not change speed C C --> See step 5 B --> See step 2 A --> See step 9
2. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING WIRING HARNESS - BODY GROUND) Disconnect the air conditioning wiring harness sub-assembly connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 4 (GND) - Body ground Always Below 1 ohms NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING WIRING HARNESS - BATTERY) Disconnect the air conditioning wiring harness sub-assembly connector. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Condition Specified Condition 1 (+B) - Body ground Always 11 to 14 V NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK AIR CONDITIONING WIRING HARNESS SUB-ASSEMBLY (SI VOLTAGE) Disconnect the E36 amplifier connector. Reconnect the air conditioning wiring harness sub-assembly connector. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition 8 (SI) - Body ground Engine switch on (IG) 4.5 to 5.5 V NG --> See step 7 OK: Go to next step
5. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - AIR CONDITIONING WIRING HARNESS) Disconnect the E36 amplifier connector. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition E36-17 (BLWH) - E36-1 (GND) Engine switch on (IG) Blower switch off 4.5 to 5.5 V NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
6. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY (BLWH SIGNAL) Remove the air conditioning amplifier assembly with its connectors still connected. Refer to «REMOVAL». Using an oscilloscope, check the waveform. MEASUREMENT CONDITION Item Content Terminal No. (Symbol) E36-17 (BLWH) - E36-1 (GND) Tool Setting 1 V/DIV., 500 μs/DIV. Condition Engine switch on (IG) Blower switch off --> on OK Waveform is as shown in the illustration. HINT: Waveform varies with the blower level. NG --> See step 10 OK: Go to next step
7. CHECK AIR CONDITIONING WIRING HARNESS SUB-ASSEMBLY (OPERATION) Replace the air conditioning wiring harness sub-assembly with a normal one and check that the condition returns to normal. OK Same problem does not occur. NG --> See step 8 OK --> REPLACE AIR CONDITIONING WIRING HARNESS SUB-ASSEMBLY
8. INSPECT REAR BLOWER MOTOR SUB-ASSEMBLY (WITH FAN) Disconnect the z31 motor connector. Connect the positive (+) lead of the battery to terminal 2 and the negative (-) lead to terminal 1, then check that the rear blower motor operates smoothly. OK The rear blower motor operates smoothly. NG --> See step 11 OK --> See step 12
9. PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to «PROBLEM SYMPTOMS TABLE»
10. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
11. REPLACE REAR BLOWER MOTOR SUB-ASSEMBLY (WITH FAN). Refer to «REMOVAL»
12. REPLACE BLOWER MOTOR CONTROLLER. Refer to «REMOVAL»(/lexus/lx/j200-2007-2012/remont/automatic-hvac-system/#blower-motor-controller-service-information)

The rear cooling unit expansion valve is controlled by the air conditioning amplifier assembly.

Scheme 355

Scheme 356

Scheme 357

1. PERFORM ACTIVE TEST USING TECHSTREAM (REAR COOLING UNIT EXPANSION VALVE) Select the Active Test, use the Techstream to generate a control command, and then check that the rear cooling unit expansion valve operates. OK Rear magnetic valve operates normally. AIR CONDITIONER Tester Display Test Part Control Range Diagnostic Note Rear A/C Mag Valve Rear Cooling Unit Expansion Valve ON or OFF - NG --> See step 2 OK --> See step 7
2. INSPECT FUSE (A/C IG) Remove the A/C IG fuse from the cowl side junction block LH. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A/C IG fuse Always Below 1 ohms NG --> REPLACE FUSE OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING WIRING HARNESS - BATTERY) Disconnect the air conditioning wiring harness sub-assembly connector. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition 2 (+S) - Body ground Engine switch off Below 1 V Engine switch on (IG) 11 to 14 V NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING WIRING HARNESS - AIR CONDITIONING AMPLIFIER) Disconnect the air conditioning wiring harness sub-assembly connector. Disconnect the E36 amplifier connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 3 (RMGV) - E36-19 (RMGV) Always Below 1 ohms 3 (RMGV) - Body ground Always 10 kohms or higher E36-19 (RMGV) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
5. CHECK REAR COOLING UNIT EXPANSION VALVE (OPERATION) Replace the rear cooling unit expansion valve. Refer to «DISASSEMBLY». HINT: Since the rear cooling unit expansion valve cannot be inspected while it is removed from the vehicle, replace the rear cooling unit expansion valve with a normal one and check that the condition returns to normal. OK Same problem does not occur. NG --> See step 6 OK --> See step 8
6. CHECK AIR CONDITIONING WIRING HARNESS SUB-ASSEMBLY (OPERATION) Replace the air conditioning wiring harness sub-assembly with a normal one and check that the condition returns to normal. OK Same problem does not occur. NG --> See step 9 OK --> REPLACE AIR CONDITIONING WIRING HARNESS SUB-ASSEMBLY
7. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»
8. REPLACE REAR COOLING UNIT EXPANSION VALVE. Refer to «DISASSEMBLY»
9. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»

The main power source is supplied to the air conditioning amplifier assembly when the engine switch is on (IG). The power source is used for operating the air conditioning amplifier assembly and servo motor, etc.

Scheme 358

The back-up power source circuit for the air conditioning amplifier assembly is shown below. Power is supplied even when turning the engine switch off and is used for diagnostic trouble code memory, etc.

Scheme 359

Scheme 360

1. INSPECT FUSE (A/C) Remove the A/C fuse from the cowl side junction block LH. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A/C fuse Always Below 1 ohms NG --> REPLACE FUSE OK: Go to next step
2. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BATTERY) Disconnect the E36 amplifier connector. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Condition Specified Condition E36-6 (+B1) - Body ground Always 11 to 14 V E36-7 (+B2) - Body ground NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 3
3. REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to «REMOVAL»

See also:
• REMOVAL