DESCRIPTION — Part 1 Lexus IS II

DESCRIPTION

This sensor detects the cabin temperature that is used as the basis for temperature control and sends a signal to the A/C amplifier.

DTC DETECTION CONDITION

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1. READ VALUE OF INTELLIGENT TESTER Connect the intelligent tester to the DLC3. Turn the engine switch on (IG) and turn the intelligent tester main switch on. Select the item below in the DATA LIST, and read the display on the intelligent tester. DATA LIST / AIR CONDITIONER: ITEM NORMAL CONDITION REFERENCE Item Measurement Item / Display (Range) Normal Condition Diagnostic Note ROOM TEMP Room temperature sensor / min.: -6.5°C (20.3°F), max.: 57.25°C (135.05°F) Actual cabin temperature is displayed - OK: The display is as specified in the normal condition column. Result RESULT REFERENCE Result Proceed to NG A OK (When troubleshooting according to the PROBLEM SYMPTOM TABLE) B OK (When troubleshooting according to the DTC) C B : PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE C : REPLACE AIR CONDITIONING AMPLIFIER A : Go to next step
2. INSPECT AIR CONDITIONING AMPLIFIER Remove the A/C amplifier with the connectors still connected. Turn the engine switch on (IG). Measure the voltage according to the value(s) in the table below. Standard voltage RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition J58-16 (TR) - J58-19 (SG-1) Engine switch on (IG) at 25°C (77°F) 1.8 to 2.2 V J58-16 (TR) - J58-19 (SG-1) Engine switch on (IG) at 40°C (104°F) 1.2 to 1.6 V HINT: As the temperature increases, the voltage decreases. Result RESULT REFERENCE Result Proceed to NG A OK (When troubleshooting according to the PROBLEM SYMPTOM TABLE) B OK (When troubleshooting according to the DTC) C B : PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE C : REPLACE AIR CONDITIONING AMPLIFIER A : Go to next step
3. INSPECT A/C ROOM TEMPERATURE SENSOR Remove the A/C room temperature sensor. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition J38-1 - J38-2 10°C (50°F) 3.00 to 3.73 kohms J38-1 - J38-2 15°C (59°F) 2.45 to 2.88 kohms J38-1 - J38-2 20°C (68°F) 1.95 to 2.30 kohms J38-1 - J38-2 25°C (77°F) 1.60 to 1.80 kohms J38-1 - J38-2 30°C (86°F) 1.28 to 1.47 kohms J38-1 - J38-2 35°C (95°F) 1.00 to 1.22 kohms J38-1 - J38-2 40°C (104°F) 0.80 to 1.00 kohms J38-1 - J38-2 45°C (113°F) 0.65 to 0.85 kohms J38-1 - J38-2 50°C (122°F) 0.50 to 0.70 kohms J38-1 - J38-2 55°C (131°F) 0.44 to 0.60 kohms J38-1 - J38-2 60°C (140°F) 0.36 to 0.50 kohms NOTE: Hold the sensor only by its connector. Touching the sensor may change the resistance value. 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: REPLACE A/C ROOM TEMPERATURE SENSOR OK: Go to next step
4. CHECK HARNESS AND CONNECTOR (A/C ROOM TEMPERATURE SENSOR - AIR CONDITIONING AMPLIFIER) Disconnect the connectors from the A/C room temperature sensor and A/C amplifier. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition J58-16 (TR) - J38-1 Always Below 1 ohms J58-19 (SG-1) - J38-2 Always Below 1 ohms J58-16 (TR) - Body ground Always 10 kohms or higher J58-19 (SG-1) - Body ground Always 10 kohms or higher NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE AIR CONDITIONING AMPLIFIER

The ambient temperature sensor is installed in front of the condenser to detect the ambient temperature which is used to control the air conditioner "AUTO" mode. This sensor connected to the ECM and detects fluctuations in the ambient temperature. This data is used for controlling the cabin temperature. The sensor sends a signal to the A/C amplifier via the ECM. 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 ECM applies voltage (5 V) to the ambient temperature sensor and reads voltage changes as the resistance of the ambient temperature sensor changes. The ECM sends the signal to the A/C amplifier via CAN and body multiplex communication.

DTC DETECTION CONDITION

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1. CHECK MULTIPLEX COMMUNICATION SYSTEM Use the intelligent tester to check if the Multiplex Communication System (MPX) is functioning normally. Result RESULT REFERENCE Result Proceed to MPX DTC is not output A MPX DTC is output B B : GO TO «MULTIPLEX COMMUNICATION SYSTEM»(ref-235578-S20958542052006062400000) A : Go to next step
2. CHECK CAN COMMUNICATION SYSTEM Use the intelligent tester to check if the CAN Communication System is functioning normally. Result RESULT REFERENCE Result Proceed to CAN DTC is not output A CAN DTC is output B B : GO TO «CAN COMMUNICATION SYSTEM»(ref-235565-S22980917632006062400000) A : Go to next step
3. READ VALUE OF INTELLIGENT TESTER Connect the intelligent tester to the DLC3. Turn the engine switch on (IG) and turn the intelligent tester main switch on. Select the item below in the DATA LIST, and read the display on the intelligent tester. DATA LIST / AIR CONDITIONER: ITEM NORMAL CONDITION REFERENCE Item Measurement Item / Display (Range) Normal Condition Diagnostic Note AMBI TEMP SENS (Ambient temperature sensor) Ambient temperature sensor / Min: -23.3°C (-9.94°F), Max: 65.95°C (150.71°F) Actual ambient temperature is displayed Open in circuit: -23.3°C (-9.94°F) Short in circuit: 65.95°C (150.71°F) OK: The display is as specified in the normal condition column. Result RESULT REFERENCE Result Proceed to NG A OK (When troubleshooting according to the PROBLEM SYMPTOMS TABLE) B OK (When troubleshooting according to the DTC) C B : PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE C : REPLACE AIR CONDITIONING AMPLIFIER A : Go to next step
4. INSPECT AMBIENT TEMPERATURE SENSOR Remove the ambient temperature sensor. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition B5-1 - B5-2 10°C (50°F) 3.00 to 3.73 kohms B5-1 - B5-2 15°C (59°F) 2.45 to 2.88 kohms B5-1 - B5-2 20°C (68°F) 1.95 to 2.30 kohms B5-1 - B5-2 25°C (77°F) 1.60 to 1.80 kohms B5-1 - B5-2 30°C (86°F) 1.28 to 1.47 kohms B5-1 - B5-2 35°C (95°F) 1.00 to 1.22 kohms B5-1 - B5-2 40°C (104°F) 0.80 to 1.00 kohms B5-1 - B5-2 45°C (113°F) 0.65 to 0.85 kohms B5-1 - B5-2 50°C (122°F) 0.50 to 0.70 kohms B5-1 - B5-2 55°C (131°F) 0.44 to 0.60 kohms B5-1 - B5-2 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: REPLACE AMBIENT TEMPERATURE SENSOR OK: Go to next step
5. CHECK WIRE HARNESS (AMBIENT TEMPERATURE SENSOR - ECM) Disconnect the ambient temperature sensor connector. Disconnect the ECM connectors. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition B5-1 - A5-18 (TAM) Always Below 1 ohms B5-2 - E5-30 (E3) Always Below 1 ohms A5-18 (TAM) - Body ground Always 10 kohms or higher E5-30 (E3) - Body ground Always 10 kohms or higher NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE ECM

The evaporator temperature sensor (A/C thermistor) is installed on the evaporator in the air conditioner unit. It detects the temperature of the cooled air that has passed through the evaporator and its signal is used to control the air conditioning. It sends a signal to the A/C amplifier. The resistance of the evaporator temperature sensor (A/C thermistor) changes in accordance with the temperature of the cooled air that has passed through the evaporator. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.

The A/C amplifier applies voltage (5 V) to the evaporator temperature sensor (A/C thermistor) and reads voltage changes as the resistance of the evaporator temperature sensor (A/C thermistor) changes. This sensor is used to prevent the evaporator from freezing.

DTC DETECTION CONDITION

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1. READ VALUE OF INTELLIGENT TESTER Connect the intelligent tester to the DLC3. Turn the engine switch on (IG) and turn the intelligent tester main switch on. Select the item below in the DATA LIST, and read the display on the intelligent tester. DATA LIST / AIR CONDITIONER: ITEM NORMAL CONDITION REFERENCE Item Measurement Item / Display (Range) Normal Condition Diagnostic Note EVAP TEMP (Evaporator temperature sensor) Evaporator temperature sensor / Min.: -29.7°C (-21.46°F), Max.: 59.55°C (139.19°F) Actual evaporator temperature is displayed Open in circuit: -29.7°C (-21.46°F) Short in circuit: 59.55°C (139.19°F) OK: The display is as specified in the normal condition column. Result RESULT REFERENCE Result Proceed to NG A OK (When troubleshooting according to the PROBLEM SYMPTOMS TABLE) B OK (When troubleshooting according to the DTC) C B : PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE C : REPLACE AIR CONDITIONING AMPLIFIER A : Go to next step
2. INSPECT AIR CONDITIONING HARNESS Remove the air conditioning harness (evaporator temperature sensor). Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition e1-5 - e1-6 -10°C (14°F) 7.30 to 9.10 kohms e1-5 - e1-6 -5°C (23°F) 5.65 to 6.95 kohms e1-5 - e1-6 0°C (32°F) 4.40 to 5.35 kohms e1-5 - e1-6 5°C (41°F) 3.40 to 4.15 kohms e1-5 - e1-6 10°C (50°F) 2.70 to 3.25 kohms e1-5 - e1-6 15°C (59°F) 2.14 to 2.58 kohms e1-5 - e1-6 20°C (68°F) 1.71 to 2.05 kohms e1-5 - e1-6 25°C (77°F) 1.38 to 1.64 kohms e1-5 - e1-6 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: REPLACE AIR CONDITIONING HARNESS OK: REPLACE AIR CONDITIONING AMPLIFIER

The smog ventilation sensor, which is installed on the front of the condenser, is used for automatic air inlet control. This sensor detects CO and HC in the emission gas and transmits signals to the A/C amplifier.

DTC DETECTION CONDITION

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1. INSPECT FUSE (LH-IG) Remove the LH-IG fuse from the cowl side junction block LH. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Item Condition Specified Condition LH-IG fuse Always Below 1 ohms NG: REPLACE FUSE (LH-IG) OK: Go to next step
2. READ VALUE OF INTELLIGENT TESTER Connect the intelligent tester to the DLC3. Turn the engine switch on (IG) and turn the intelligent tester main switch on. Allow exhaust gas (HC, CO) to travel to the sensing portion of the smog ventilation sensor. Select the item below in the DATA LIST, and read the display on the intelligent tester. DATA LIST / AIR CONDITIONER: ITEM NORMAL CONDITION REFERENCE Item Measure Item / Display (Range) Normal Condition Diagnostic Note EMISS GAS SENS (Emission gas sensor) Emission gas / Min.: 0 V, Max.: 255 V Smog ventilation sensor value increases as gas amount increases - OK: The display is as specified in the normal condition column. Result RESULT REFERENCE Result Proceed to NG A OK (When troubleshooting according to the PROBLEM SYMPTOMS TABLE) B OK (When troubleshooting according to the DTC) C B : PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE C : REPLACE AIR CONDITIONING AMPLIFIER A : Go to next step
3. CHECK WIRE HARNESS (SMOG VENTILATION SENSOR - BODY GROUND) Disconnect the smog ventilation sensor connector. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition B11-6 (E) - Body ground Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK WIRE HARNESS (SMOG VENTILATION SENSOR - BATTERY) Disconnect the smog ventilation sensor connector. Measure the voltage according to the value(s) in the table below. Standard voltage VOLTAGE SPECIFICATION Tester Connection Condition Specified Condition B11-3 (IG) - Body ground Engine switch on (IG) 10 to 14 V Engine switch off Below 1 V NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
5. INSPECT SMOG VENTILATION SENSOR Remove the smog ventilation sensor. Apply battery voltage between terminals 3 (IG) and 6 (E). Allow exhaust gas (HC, CO) to travel to the sensing portion of the smog ventilation sensor, and measure the resistance between terminals 1 (SG) and 2 (DGS). OK: When the sensor is exposed to the exhaust gas, the resistance increases. HINT: The resistance before blowing exhaust gas is 10 kohms to 40 kohms. NG: REPLACE SMOG VENTILATION SENSOR OK: Go to next step
6. CHECK WIRE HARNESS (SMOG VENTILATION SENSOR - A/C AMPLIFIER) Disconnect the smog ventilation sensor. Disconnect the A/C amplifier connector. Measure the resistance of the wire harness side connectors. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition B11-1 (SG) - J58-39 (SG-6) Always Below 1 ohms B11-2 (DGS) - J58-34 (DGS) Always Below 1 ohms J58-39 (SG-6) - Body ground Always 10 kohms or higher J58-34 (DGS) - Body ground Always 10 kohms or higher NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE AIR CONDITIONING AMPLIFIER

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The 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 voltage from the solar sensor varies according to the amount of sunlight. When the sunlight increases, the output voltage increases. As the sunlight decreases, the output voltage decreases. The A/C amplifier detects voltage output from the solar sensor.

DTC DETECTION CONDITION

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HINT

1. If DTC B1244 is output at the same time, troubleshoot DTC B1244 first.
2. If the check is performed in a dark place, DTC B1421/21 or B1424/24 (solar sensor circuit abnormal) may be output.

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1. READ VALUE OF INTELLIGENT TESTER Connect the intelligent tester to the DLC3. Turn the engine switch on (IG) and turn the intelligent tester main switch on. Expose the sensing portion of the solar sensor to light. HINT: Use an incandescence light for inspection. Select the item below in the DATA LIST, and read the display on the intelligent tester. DATA LIST / AIR CONDITIONER: ITEM NORMAL CONDITION REFERENCE Item Measure Item / Display (Range) Normal Condition Diagnostic Note SOLAR SENS-P (Solar sensor (P side)) Passenger side solar sensor / Min.: 0, Max.: 255 Passenger side solar sensor value increases as brightness increases - OK: The display is as specified in the normal condition column. Result RESULT REFERENCE Result Proceed to NG A OK (When troubleshooting according to the PROBLEM SYMPTOMS TABLE) B OK (When troubleshooting according to the DTC) C B : PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE C : REPLACE AIR CONDITIONING AMPLIFIER A : Go to next step
2. CHECK WIRE HARNESS (SOLAR SENSOR) Disconnect the solar sensor connector. Measure the voltage according to the value(s) in the table below. Standard voltage VOLTAGE SPECIFICATION Tester Connection Condition Specified Condition K1-6 (CLTB) - K1-3 (CLTE) Engine switch off Below 1 V K1-6 (CLTB) - K1-3 (CLTE) Engine switch on (IG) 10 to 14 V OK: Go to step 4 NG: Go to next step
3. CHECK WIRE HARNESS (MAIN BODY ECU RH - SOLAR SENSOR) Disconnect the main body ECU RH connector. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition J74-6 (CLTB) - K1-6 (CLTB) Always Below 1 ohms J74-4 (CLTE) - K1-3 (CLTE) Always Below 1 ohms J74-6 (CLTB) - Body ground Always 10 kohms or higher J74-4 (CLTE) - Body ground Always 10 kohms or higher NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE MAIN BODY ECU RH
4. CHECK SOLAR SENSOR Remove the solar sensor with its connector still connected. 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 VOLTAGE SPECIFICATION Tester Connection Condition Specified Condition K1-2 (TSR) - K1-3 (CLTE) Sensor is subjected to electric light 0.8 to 4.3 V K1-2 (TSR) - K1-3 (CLTE) Sensor is covered with a cloth Below 0.8 V NOTE: The connection procedure for using a digital tester such as a TOYOTA electrical tester is shown above. When using an analog tester, connect the negative (-) lead to terminal 2 and positive (+) lead to terminal 1 of the solar sensor. While using the battery during inspection, do not bring the positive and negative tester probes too close to each other as a short circuit may occur. HINT: Use an incandescent light for inspection. Bring it within about 30 cm (11.8 in.) of the solar sensor. As the inspection light is moved away from the sensor, the voltage increases. NG: REPLACE SOLAR SENSOR OK: Go to next step
5. CHECK WIRE HARNESS (SOLAR SENSOR - A/C AMPLIFIER) Disconnect the solar sensor connector. Disconnect the A/C amplifier connector. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition J58-14 (TSP) -K1-2 (TSR) Always Below 1 ohms J58-14 (TSP) - Body ground Always 10 kohms or higher NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE AIR CONDITIONING AMPLIFIER

This sensor sends 1 pulse per engine revolution to the ECM.

If the ratio between engine and compressor speed deviates 20% or more compared to normal operation, the ECM turns the cooler compressor off and the indicator blinks at approximately 1 second intervals. The ECM informs the A/C amplifier of the operation condition of the cooler compressor through multiplex communication (CAN and BEAN).

DTC DETECTION CONDITION

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1. CHECK MULTIPLEX COMMUNICATION SYSTEM Use the intelligent tester to check if the Multiplex Communication System (MPX) is functioning normally. Result RESULT REFERENCE Result Proceed to MPX DTC is not output A MPX DTC is output B B : GO TO «MULTIPLEX COMMUNICATION SYSTEM»(ref-235578-S20958542052006062400000) A : Go to next step
2. CHECK CAN COMMUNICATION SYSTEM Use the intelligent tester to check if the CAN Communication System is functioning normally. Result RESULT REFERENCE Result Proceed to CAN DTC is not output A CAN DTC is output B B : GO TO «CAN COMMUNICATION SYSTEM»(ref-235565-S22980917632006062400000) A : Go to next step
3. INSPECT ECM Remove the ECM with its connectors still connected. Measure the waveform of the connector. Standard TESTER SPECIFICATION CONNECTION Tester Connection Condition Specified Condition E3-10 (LCKI) - Body ground Engine switch on (IG) AUTO switch ON A/C switch ON Magnetic clutch ON Pulse generation ITEM CONTENTS Item Contents Tool setting 200 mV/DIV., 10 ms/DIV. Vehicle condition Engine switch on (IG) AUTO switch ON A/C switch ON Magnetic clutch ON Result RESULT REFERENCE Result Proceed to NG A OK (When troubleshooting according to the PROBLEM SYMPTOMS TABLE) B OK (When troubleshooting according to the DTC) C B : PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE C : REPLACE ECM A : Go to next step
4. INSPECT A/C COMPRESSOR (LOCK SENSOR) Disconnect the A/C compressor connector. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Specified Condition E8-2 (SSR+) - E8-5 (SSR-) 160 to 320 ohms NG: REPLACE A/C COMPRESSOR (LOCK SENSOR) OK: Go to next step
5. CHECK WIRE HARNESS (ECM - A/C COMPRESSOR) Disconnect the A/C compressor connector. Disconnect the ECM connector. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition E3-10 (LCKI) - E8-2 (SSR+) Always Below 1 ohms E3-10 (LCKI) - Body ground Always 10 kohms or higher E8-5 (SSR-) - Body ground Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE ECM

This DTC is output when refrigerant pressure is extremely low (0.19 MPa (2.0 kgf/cm 2 , 28 psi) or less) or extremely high (3.14 MPa (32.0 kgf/cm 2 , 455 psi) or more). The pressure sensor, which is installed on the pipe of the high pressure side to detect refrigerant pressure, outputs a refrigerant pressure signal to the A/C amplifier. The A/C amplifier converts this 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 output if there is no refrigerant in the system.

DTC DETECTION CONDITION

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1. CHECK REFRIGERANT Check the sight glass of the cooler unit refrigerant liquid pipe. Prepare the vehicle according to the chart below. ITEM CONDITION Item Condition Vehicle Doors Fully open Temperature Setting MAX COLD Blower Speed HI A/C ON Compare the sight glass to the following chart. SIGHT GLASS REFERENCE Item Symptom Amount of Refrigerant Corrective Actions 1 Bubbles visible Insufficient (1) Check for gas leakage and repair if necessary Add refrigerant until bubbles disappear 2 No bubbles visible Empty, insufficient, or excessive Refer to 3 and 4 3 No temperature difference between compressor inlet and outlet Empty or nearly empty Check for gas leakage with gas leak detector and repair if necessary Evacuate A/C system and recharge with proper amount of refrigerant 4 Considerable temperature difference between compressor inlet and outlet Proper or excessive Refer to 5 and 6 5 Immediately after air conditioning is turned OFF, refrigerant clears Excessive Recover refrigerant Evacuate A/C system and recharge with proper amount of refrigerant 6 Immediately after air conditioning is turned OFF, refrigerant foams and then becomes clear Proper - (1) Bubbles in the sight glass with the vehicle interior temperature above 35°C (95°F) can be considered normal if cooling is sufficient. NG: CHARGE REFRIGERANT OK: Go to next step
2. CHECK WIRE HARNESS (PRESSURE SENSOR - A/C AMPLIFIER) Disconnect the pressure sensor connector. Disconnect the A/C amplifier connector. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition B7-2 (PR) - J58-13 (PRE) Always Below 1 ohms B7-3 (+) - J58-26 (S5-2) Always Below 1 ohms B7-1 (-) - J58-38 (SG-2) Always Below 1 ohms J58-13 (PRE) - Body ground Always 10 kohms or higher J58-26 (S5-2) - Body ground Always 10 kohms or higher J58-38 (SG-2) - Body ground Always 10 kohms or higher NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. INSPECT PRESSURE SENSOR Install the manifold gauge set (See «ON-VEHICLE INSPECTION»(ref-235579-S02659531892006062400000) ). Connect the three 1.5 V dry cell battery's positive (+) lead to terminal 3 and the negative (-) lead to terminal 1. Then connect the voltmeter's positive (+) lead to terminal 2 and the negative (-) lead to terminal 1. Measure the voltage. OK: The voltage changes according to refrigerant pressure, as shown in the graph. Result RESULT REFERENCE Result Proceed to NG A OK (When troubleshooting according to the DTC) B OK (When troubleshooting according to the PROBLEM SYMPTOMS TABLE) C B : REPLACE AIR CONDITIONING AMPLIFIER C : PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE A : REPLACE PRESSURE SENSOR

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The 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 voltage from the solar sensor varies according to the amount of sunlight. When the sunlight increases, the output voltage increases. As the sunlight decreases, the output voltage decreases. The A/C amplifier detects output voltage from the solar sensor.

DTC DETECTION CONDITION

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HINT

1. If DTC B1244 is output at the same time, troubleshoot DTC B1244 first.
2. If the check is performed in a dark place, DTC B1421/21 or B1424/24 (solar sensor circuit abnormal) may be output.

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1. READ VALUE OF INTELLIGENT TESTER Connect the intelligent tester to the DLC3. Turn the engine switch on (IG) and turn the intelligent tester main switch on. Expose the sensing portion of the solar sensor to light. HINT: Use an incandescence light for inspection. Select the item below in the DATA LIST, and read the display on the intelligent tester. DATA LIST / AIR CONDITIONER: ITEM NORMAL CONDITION REFERENCE Item Measure Item / Display (Range) Normal Condition Diagnostic Note SOLAR SENS-D (Solar sensor (D side)) Driver side solar sensor / Min.: 0, Max.: 255 Driver side solar sensor value increases as brightness increases - OK: The display is as specified in the normal condition column. Result RESULT REFERENCE Result Proceed to NG A OK (When troubleshooting according to the PROBLEM SYMPTOMS TABLE) B OK (When troubleshooting according to the DTC) C B : PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE C : REPLACE AIR CONDITIONING AMPLIFIER A : Go to next step
2. CHECK WIRE HARNESS (SOLAR SENSOR) Disconnect the solar sensor connector. Measure the voltage according to the value(s) in the table below. Standard voltage VOLTAGE SPECIFICATION Tester Connection Condition Specified Condition K1-6 (CLTB) - K1-3 (CLTE) Engine switch on (IG) 10 to 14 V K1-6 (CLTB) - K1-3 (CLTE) Engine switch off Below 1 V OK: Go to step 4 NG: Go to next step
3. CHECK WIRE HARNESS (SOLAR SENSOR - MAIN BODY ECU RH) Disconnect the main body ECU RH connector. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition J74-6 (CLTB) - K1-6 (CLTB) Always Below 1 ohms J74-4 (CLTE) - K1-3 (CLTE) Always Below 1 ohms J74-6 (CLTB) - Body ground Always 10 kohms or higher J74-4 (CLTE) - Body ground Always 10 kohms or higher NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE MAIN BODY ECU RH
4. CHECK SOLAR SENSOR Remove the solar sensor with its connector still connected. 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 VOLTAGE SPECIFICATION Tester Connection Condition Specified Condition K1-1 (TSL) - K1-3 (CLTE) Sensor is subjected to electric light 0.8 to 4.3 V K1-1 (TSL) - K1-3 (CLTE) Sensor is covered with a cloth Below 0.8 V NOTE: The connection procedure for using a digital tester such as a TOYOTA electrical tester is shown above. When using an analog tester, connect the negative (-) lead to terminal 2 and positive (+) lead to terminal 1 of the solar sensor. While using the battery during inspection, do not bring the positive and negative tester probes too close to each other as a short circuit may occur. HINT: Use an incandescent light for inspection. Bring it about 30 cm (11.8 in.) from the solar sensor. As the inspection light is moved away from the sensor, the voltage increases. NG: REPLACE SOLAR SENSOR OK: Go to next step
5. CHECK WIRE HARNESS (SOLAR SENSOR - A/C AMPLIFIER) Disconnect the solar sensor connector. Disconnect the A/C amplifier connector. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition J58-35 (TSD) - K1-1 (TSL) Always Below 1 ohms J58-35 (TSD) - Body ground Always 10 kohms or higher NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE AIR CONDITIONING AMPLIFIER

The air mix damper servo sends pulse signals to inform the air conditioner amplifier of the damper position. The air conditioner amplifier activates the motor (normal, reverse) based on the signals to move the air mix damper (passenger seat) to any position, which adjusts the amount of air passing the heater core after passing the evaporator to control the blowing temperature.

HINT

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

DTC DETECTION CONDITION

Scheme 55

1. READ VALUE OF INTELLIGENT TESTER Connect the intelligent tester to the DLC3. Turn the engine switch on (IG) and turn the intelligent tester main switch on. Operate the front passenger side temperature adjustment switch. Select the item below in the DATA LIST, and read the display on the intelligent tester. DATA LIST / AIR CONDITIONER: ITEM NORMAL CONDITION REFERENCE Item Measurement Item / Display (Range) Normal Condition Diagnostic Note AIR MIX PULSE-P (Air mix servomotor target pulse (P side)) Passenger side air mix servo motor target pulse / Min.: 0, Max.: 255 MAX. COLD: 105 (pulse) MAX. HOT: 6 (pulse) - OK: The display is as specified in the normal condition column. Result RESULT REFERENCE Result Proceed to NG A OK (When troubleshooting according to the PROBLEM SYMPTOMS TABLE) B OK (When troubleshooting according to the DTC) C B : PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE C : REPLACE AIR CONDITIONING AMPLIFIER A : Go to next step
2. REPLACE AIR MIX CONTROL SERVO MOTOR HINT: Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a normal one and check that the condition returns to normal. Check for DTCs. Result RESULT REFERENCE Result Proceed to DTC B1441/41 is output A DTC B1441/41 is not output B B : END A : REPLACE AIR CONDITIONING HARNESS

The damper servo (air inlet control) sends pulse signals to inform the air conditioner amplifier of the damper position. The air conditioner amplifier activates the motor (normal, reverse) based on the signals to move the air inlet mode selection air inlet control 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 diagnostic code can be output when either a damper link or damper is mechanically locked.

DTC DETECTION CONDITION

Scheme 56

1. READ VALUE OF INTELLIGENT TESTER Connect the intelligent tester to the DLC3. Turn the engine switch on (IG) and turn the intelligent tester main switch on. Operate the R/F (Recirculation/Fresh) switch. Select the item below in the DATA LIST, and read the display on the intelligent tester. DATA LIST / AIR CONDITIONER: ITEM NORMAL CONDITION REFERENCE Item Measurement Item / Display (Range) Normal Condition Diagnostic Note A/I DAMP PLS (Air inlet damper target pulse) Air inlet damper target pulse / Min.: 0, Max.: 255 RECIRCULATION: 31 (pulse) FRESH: 7 (pulse) - OK: The display is as specified in the normal condition column. Result RESULT REFERENCE Result Proceed to NG A OK (When troubleshooting according to the PROBLEM SYMPTOMS TABLE) B OK (When troubleshooting according to the DTC) C B : PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE C : REPLACE AIR CONDITIONING AMPLIFIER A : Go to next step
2. REPLACE AIR INLET CONTROL SERVO MOTOR HINT: Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a normal one and check that the condition returns to normal. Check for DTCs. Result RESULT REFERENCE Result Proceed to DTC B1442/42 is output A DTC B1442/42 is not output B B : END A : REPLACE AIR CONDITIONING HARNESS

The mode damper servo sends pulse signals to inform the air conditioner amplifier of the damper position. The air conditioner amplifier activates the motor (normal, reverse) based on the signals to move the mode damper to any position, which controls the air outlet switching.

HINT

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

DTC DETECTION CONDITION

Scheme 57

1. READ VALUE OF INTELLIGENT TESTER Connect the intelligent tester to the DLC3. Turn the engine switch on (IG) and turn the intelligent tester main switch on. Operate the MODE switch. Select the item below in the DATA LIST, and read the display on the intelligent tester. DATA LIST / AIR CONDITIONER: ITEM NORMAL CONDITION REFERENCE Item Measurement Item / Display (Range) Normal Condition Diagnostic Note AIR OUT PULSE-D (Air outlet servomotor target pulse (D side)) Driver side air outlet servo motor target pulse / Min.: 0, Max.: 255 FACE: 9 to 17 (pulse) B/L: 32 to 38 (pulse) FOOT: 45 to 70 (pulse) FOOT/DEF: 84 (pulse) DEF: 97 (pulse) - OK: The display is as specified in the normal condition column. Result RESULT REFERENCE Result Proceed to NG A OK (When troubleshooting according to the PROBLEM SYMPTOMS TABLE) B OK (When troubleshooting according to the DTC) C B : PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE C : REPLACE AIR CONDITIONING AMPLIFIER A : Go to next step
2. REPLACE AIR OUTLET CONTROL SERVO MOTOR HINT: Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a normal one and check that the condition returns to normal. Check for DTCs. Result RESULT REFERENCE Result Proceed to DTC B1443/43 is output A DTC B1443/43 is not output B B : END A : REPLACE AIR CONDITIONING HARNESS

The damper servo (cool air by-pass) sends pulse signals to inform the air conditioner amplifier of the damper position. The air conditioner amplifier activates the motor (normal, reverse) based on the signals to move the damper to any position. As a result, when the A/C is operating, the temperature of the air blowing toward the passenger's head area is controlled.

HINT

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

DTC DETECTION CONDITION

Scheme 58

1. READ VALUE OF INTELLIGENT TESTER Connect the intelligent tester to the DLC3. Turn the engine switch on (IG) and turn the intelligent tester main switch on. Expose the sensing portion of the solar sensor to light. Select the item below in the DATA LIST, and read the display on the intelligent tester. DATA LIST / AIR CONDITIONER: ITEM NORMAL CONDITION REFERENCE Item Measurement Item / Display (Range) Normal Condition Diagnostic Note A/B DAMP PLS (Cool air bypass pulse) Passenger side cool air by-pass pulse / Min.: 0, Max.: 255 CLOSE: 50 (pulse) OPEN: 8 (pulse) - OK: The display is as specified in the normal condition column. Result RESULT REFERENCE Result Proceed to NG A OK (When troubleshooting according to the PROBLEM SYMPTOMS TABLE) B OK (When troubleshooting according to the DTC) C B : PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE C : REPAIR AIR CONDITIONING AMPLIFIER A : Go to next step
2. REPLACE COOL AIR BY-PASS CONTROL SERVO MOTOR HINT: Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a normal one and check that the condition returns to normal. Check for DTCs. Result RESULT REFERENCE Result Proceed to DTC B1445/45 is output A DTC B1445/45 is not output B B : END A : REPAIR AIR CONDITIONING HARNESS

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

HINT

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

DTC DETECTION CONDITION

Scheme 59

1. READ VALUE OF INTELLIGENT TESTER Connect the intelligent tester to the DLC3. Turn the engine switch on (IG) and turn the intelligent tester main switch on. Operate the driver side temperature adjustment switch. Select the item below in the DATA LIST, and read the display on the intelligent tester. DATA LIST / AIR CONDITIONER: ITEM NORMAL CONDITION REFERENCE Item Measurement Item / Display (Range) Normal Condition Diagnostic Note AIR MIX PULSE-D (Air mix servomotor target pulse (D side)) Driver side air mix servo motor target pulse / Min.: 0, Max.: 255 MAX COLD: 5 (pulse) MAX HOT: 104 (pulse) - OK: The display is as specified in the normal condition column. Result RESULT REFERENCE Result Proceed to NG A OK (When troubleshooting according to the PROBLEM SYMPTOMS TABLE) B OK (When troubleshooting according to the DTC) C B : PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE C : REPLACE AIR CONDITIONING AMPLIFIER A : Go to next step
2. REPLACE AIR MIX CONTROL SERVO MOTOR HINT: Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a normal one and check that the condition returns to normal. Check for DTCs. Result RESULT REFERENCE Result Proceed to DTC B1446/46 is output A DTC B1446/46 is not output B B : END A : REPLACE AIR CONDITIONING HARNESS

In this circuit, the compressor receives a refrigerant compression demand signal from the air conditioning amplifier.

Based on this signal, the compressor changes the amount of compressor output.

DTC DETECTION CONDITION

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1. INSPECT A/C COMPRESSOR Disconnect the A/C compressor connector. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition E8-3 (SOL+) - E8-6 (SOL-) 20°C (68°F) 10 to 11 ohms NG: REPLACE A/C COMPRESSOR OK: Go to next step
2. CHECK WIRE HARNESS (A/C COMPRESSOR - BODY GROUND) Disconnect the A/C compressor connector. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition E8-6 (SOL-) - Body ground Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. CHECK WIRE HARNESS (A/C COMPRESSOR - A/C AMPLIFIER) Disconnect the A/C compressor connector. Disconnect the A/C amplifier connector. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition J58-5 (SOL+) - E8-3 (SOL+) Always Below 1 ohms J58-5 (SOL+) - Body ground Always 10 kohms or higher Result RESULT REFERENCE Result Proceed to NG A OK (When troubleshooting according to the PROBLEM SYMPTOMS TABLE) B OK (When troubleshooting according to the DTC) C B : PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE C : REPLACE AIR CONDITIONING AMPLIFIER A : REPAIR OR REPLACE HARNESS OR CONNECTOR

The smog ventilation sensor detects NOx in the emission gas and transmits signals to the A/C amplifier. Based on the signals, the A/C amplifier performs automatic air inlet control (FRESH, FRESH / RECIRCULATION, or RECIRCULATION mode).

DTC DETECTION CONDITION

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1. INSPECT FUSE (LH-IG) Remove the LH-IG fuse from the cowl side junction block LH. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Item Condition Specified Condition LH-IG fuse Always Below 1 ohms NG: REPLACE FUSE (LH-IG) OK: Go to next step
2. READ VALUE OF INTELLIGENT TESTER Connect the intelligent tester to the DLC3. Turn the engine switch on (IG) and turn the intelligent tester main switch on. Allow exhaust gas (NOx) to travel to the sensing portion of the smog ventilation sensor. Select the item below in the DATA LIST, and read the display on the intelligent tester. DATA LIST / AIR CONDITIONER: ITEM NORMAL CONDITION REFERENCE Item Measure Item / Display (Range) Normal Condition Diagnostic Note NOX GAS SENS (Emission gas Nox sensor) Emission gas NOx sensor / Min.: 0, Max.: 255 Smog ventilation sensor value increases as gas amount increases - OK: The display is as specified in the normal condition column. Result RESULT REFERENCE Result Proceed to NG A OK (When troubleshooting according to the PROBLEM SYMPTOMS TABLE) B OK (When troubleshooting according to the DTC) C B : PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE C : REPLACE AIR CONDITIONING AMPLIFIER A : Go to next step
3. CHECK WIRE HARNESS (SMOG VENTILATION SENSOR - BODY GROUND) Disconnect the smog ventilation sensor connector. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition B11-6 (E) - Body ground Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK WIRE HARNESS (SMOG VENTILATION SENSOR - BATTERY) Disconnect the smog ventilation sensor connector. Measure the voltage according to the value(s) in the table below. Standard voltage VOLTAGE SPECIFICATION Tester Connection Condition Specified Condition B11-3 (IG) - Body ground Engine switch on (IG) 10 to 14 V Engine switch off Below 1 V NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
5. INSPECT SMOG VENTILATION SENSOR Remove the smog ventilation sensor. Apply battery voltage between terminals 3 (IG) and 6 (E). Allow exhaust gas (NOx) to travel to the sensing portion of the smog ventilation sensor, and measure the resistance between terminals 1 (SG) and 4 (DGS1). OK: When the sensor is exposed to the exhaust gas, the resistance increases. HINT: The resistance before blowing exhaust gas is 10 kohms to 40 kohms. NG: REPLACE SMOG VENTILATION SENSOR OK: Go to next step
6. CHECK WIRE HARNESS (SMOG VENTILATION SENSOR - A/C AMPLIFIER) Disconnect the exhaust gas sensor connector. Disconnect the A/C amplifier connector. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition B11-1 (SG) - J58-39 (SG-6) Always Below 1 ohms B11-4 (DGS1) - J58-33 (DGS1) Always Below 1 ohms J58-39 (SG-6) - Body ground Always 10 kohms or higher J58-33 (DGS1) - Body ground Always 10 kohms or higher NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE AIR CONDITIONING AMPLIFIER

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

DTC DETECTION CONDITION

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1. CHECK HARNESS AND CONNECTOR Remove the A/C amplifier. Disconnect the connector from the A/C amplifier. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition J58-20 (GND) - Body ground Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
2. CHECK AIR CONDITIONING AMPLIFIER Reconnect the connector to the A/C amplifier. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition e1-2 (BUS G) - J58-20 (GND) Always Below 1 ohms NG: REPLACE AIR CONDITIONING AMPLIFIER OK: Go to next step
3. CHECK AIR CONDITIONING AMPLIFIER Measure the voltage according to the value(s) in the table below. Standard voltage VOLTAGE SPECIFICATION Tester Connection Condition Specified Condition e1-4 (B BUS) - e1-2 (BUS G) Engine switch off Below 1 V e1-4 (B BUS) - e1-2 (BUS G) Engine switch on (IG) 10 to 14 V NG: REPLACE AIR CONDITIONING AMPLIFIER OK: REPLACE AIR CONDITIONING HARNESS

DTC DETECTION CONDITION

HINT

Refer to MULTIPLEX COMMUNICATION SYSTEM .

Scheme 73

The blower motor is operated by signals from the A/C amplifier. The blower motor speed is controlled using various duty ratios.

Duty Ratio

The duty ratio is the ratio of the blower motor ON time (A) to the total of the blower motor ON and OFF time (A + B).

The blower motor controller controls the blower motor speed.

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1. PERFORM ACTIVE TEST BY INTELLIGENT TESTER Connect the intelligent tester to the DLC3. Turn the engine switch on (IG) and turn the intelligent tester main switch on. Select the item below in the ACTIVE TEST and then check that the relay operates. ACTIVE TEST / AIR CONDITIONER: ITEM NORMAL CONDITION REFERENCE Item Test Details / Display (Range) Diagnostic Note BLOWER MOTOR (Blower motor) Blower motor / Min.: Level 01, Max.: Level 31 - Result RESULT REFERENCE Result Proceed to OK A NG (blower motor does not operate) B NG (blower motor operates but does not change speed) C B : Go to step 2 C : Go to step 6 A : PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
2. INSPECT FUSE Remove the HEATER fuse from the engine room R/B and J/B No. 1. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Item Condition Specified Condition HEATER fuse Always Below 1 ohms NG: REPLACE FUSE (HEATER) OK: Go to next step
3. CHECK WIRE HARNESS (BLOWER MOTOR - BODY GROUND) Disconnect the blower motor connector. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition A34-1 (GND) (1) - Body ground Always Below 1 ohms b1-1 (GND) (2) - Body ground Always Below 1 ohms HINT: (1) 4GR-FSE (2) 2GR-FSE NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK WIRE HARNESS (BLOWER MOTOR - BATTERY) Disconnect the blower motor connector. Measure the voltage according to the value(s) in the table below. Standard voltage VOLTAGE SPECIFICATION Tester Connection Condition Specified Condition A34-3 (+B) (1) - Body ground Always 10 to 14 V b1-3 (+B) (2) - Body ground Always 10 to 14 V HINT: (1) 4GR-FSE (2) 2GR-FSE NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
5. INSPECT BLOWER MOTOR Disconnect the A/C amplifier connector. Connect the blower motor connector. Measure the voltage according to the value(s) in the table below. Standard voltage VOLTAGE SPECIFICATION Tester Connection Condition Specified Condition A34-2 (SI) (1) - Body ground Engine switch on (IG) 4.5 to 5.5 V b1-2 (SI) (2) - Body ground Engine switch on (IG) 4.5 to 5.5 V HINT: (1) 4GR-FSE (2) 2GR-FSE NG: REPLACE BLOWER MOTOR OK: Go to next step
6. CHECK WIRE HARNESS (A/C AMPLIFIER - BODY GROUND) Disconnect the A/C amplifier connector. Measure the voltage according to the value(s) in the table below. Standard voltage VOLTAGE SPECIFICATION Tester Connection Condition Specified Condition J58-11 (BLW) - Body ground Engine switch on (IG) 4.5 to 5.5 V NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go To Next Step
7. INSPECT AIR CONDITIONING AMPLIFIER Remove the A/C amplifier with its connectors still connected. Turn the engine switch on (IG) . Turn the blower switch ON (Lo). Measure the waveform between terminal J58-11 (BLW) of the A/C amplifier and body ground. OK: Waveform is as shown in the illustration. HINT: Waveform varies with the blower level. ITEM CONTENTS REFERENCE Item Contents Tool setting 1 V/DIV., 500 $$s/DIV. Vehicle condition Engine switch on (IG) Blower switch ON (Lo) NG: REPLACE AIR CONDITIONING AMPLIFIER OK: REPLACE BLOWER MOTOR

The A/C amplifier sends a magnetic clutch ON command signal to the ECM through the BEAN line and CAN line. Then the ECM turns the A/C COMP relay on to turn the magnetic clutch on.

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1. CHECK MULTIPLEX COMMUNICATION SYSTEM Use the intelligent tester to check if the Multiplex Communication System (MPX) is functioning normally. Result RESULT REFERENCE Result Proceed to MPX DTC is not output A MPX DTC is output B B : GO TO «MULTIPLEX COMMUNICATION SYSTEM»(ref-235578-S20958542052006062400000) A : Go to next step
2. CHECK CAN COMMUNICATION SYSTEM Use the intelligent tester to check if the CAN Communication System is functioning normally. Result RESULT REFERENCE Result Proceed to CAN DTC is not output A CAN DTC is output B B : GO TO «CAN COMMUNICATION SYSTEM»(ref-235565-S22980917632006062400000) A : Go to next step
3. READ VALUE OF INTELLIGENT TESTER Connect the intelligent tester to the DLC3. Turn the engine switch on (IG) and turn the intelligent tester main switch on. Turn the A/C switch on and off. Select the item below in the DATA LIST, and read the display on the intelligent tester. DATA LIST / ECM: ITEM NORMAL CONDITION REFERENCE Item Measure Item Normal Condition Diagnostic Note A/C SIG (A/C Signal) A/C signal / ON or OFF ON: A/C ON OFF: A/C OFF - OK: The display is as specified in the normal condition column. NG: Go to step 12 OK: Go To Next Step
4. READ VALUE OF INTELLIGENT TESTER Connect the intelligent tester to the DLC3. Turn the engine switch on (IG) and turn the intelligent tester main switch on. Change the blower fan speed to LO using the blower switch. Turn the A/C switch on and off. Select the item below in the DATA LIST, and read the display on the intelligent tester. DATA LIST / ECM: ITEM NORMAL CONDITION REFERENCE Item Measure Item Normal Condition Diagnostic Note A/C MAG CLUTCH (A/C magnetic clutch relay) A/C magnetic clutch relay / OFF, ON ON: A/C magnetic clutch ON OFF: A/C magnetic clutch OFF - OK: The display is as specified in the normal condition. NG: REPLACE ECM OK: Go to next step
5. PERFORM ACTIVE TEST BY INTELLIGENT TESTER Connect the intelligent tester to the DLC3. Turn the engine switch on (IG) and turn the intelligent tester main switch on. Select the item below in the ACTIVE TEST and read the display on the intelligent tester. ACTIVE TEST / ECM: ACTIVE TEST DETAILS Item Test Details / Display (Range) Diagnostic Note A/C MAG CLUTCH Magnetic Clutch Relay / OFF, ON - OK: The magnetic clutch operates normally. OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE NG: Go to next step
6. INSPECT FUSE (A/C COMP) Remove the A/C COMP fuse from the engine room R/B and J/B No. 2. Measure the resistance of the fuse. Standard resistance RESISTANCE SPECIFICATION Tester Item Condition Specified Condition A/C COMP fuse Always Below 1 ohms NG: REPLACE FUSE (A/C COMP) OK: Go to next step
7. INSPECT RELAY (A/C COMP) Remove the A/C COMP relay from the engine room R/B and J/B No. 2. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Specified Condition 3 -- 5 10 kohms or higher 3 -- 5 Below 1 ohms (when battery voltage is applied to terminals 1 and 2) NG: REPLACE RELAY (A/C COMP) OK: Go To Next Step
8. INSPECT A/C COMPRESSOR Disconnect the A/C compressor connector. Disconnect the magnetic clutch connector. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition E8-1 (MG+) - A-1 Always Below 1 ohms E8-1 (MG+) - Body ground Always 10 kohms or higher NG: REPLACE A/C COMPRESSOR OK: Go to next step
9. INSPECT MAGNETIC CLUTCH Measure the resistance of the connector. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition A-1 - Body ground Always 3.4 to 3.8 ohms When connector terminal A1 is connected to the positive (+) battery terminal, check that the following occurs: 1) the magnetic clutch's operating sound can be heard, and 2) the magnetic clutch's hub and rotor lock. NG: REPLACE MAGNETIC CLUTCH OK: Go to next step
10. CHECK WIRE HARNESS (ENGINE ROOM R/B AND J/B NO. 2 - A/C COMPRESSOR) Turn the engine switch on (IG). Measure the voltage according to the value(s) in the table below. Standard voltage VOLTAGE SPECIFICATION Tester Connection Specified Condition Relay block A/C COMP relay terminal 5 - Body ground 10 to 14 V Relay block A/C COMP relay terminal 1 - Body ground 10 to 14 V NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
11. CHECK WIRE HARNESS (ENGINE ROOM R/B AND J/B NO. 2 - ECM) Disconnect the ECM connector. Measure the resistance according to the value(s) in the table below. Standard resistance 4GR-FSE RESISTANCE SPECIFICATION Tester Connection Specified Condition Relay block A/C COMP relay terminal 2 - A6-13 (ACMG) Below 1 ohms A6-13 (ACMG) - Body ground 10 kohms or higher 2GR-FSE RESISTANCE SPECIFICATION Tester Connection Specified Condition Relay block A/C COMP relay terminal 2 - A6-11 (ACMG) Below 1 ohms A6-11 (ACMG) - Body ground 10 kohms or higher NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPAIR OR REPLACE HARNESS OR CONNECTOR (A/C COMPRESSOR - ENGINE ROOM R/B AND J/B NO. 2)
12. REPLACE AIR CONDITIONING AMPLIFIER Replace the A/C amplifier with a normal one and check that the condition returns to normal. OK: Same problem does not occur. OK: END NG: REPLACE ECM

The GLW RLY turns on when it receives a signal from the A/C amplifier. As a result, power is supplied to the heater glow plug.

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1. INSPECT FUSE (LH-IG, GLW PLG1, GLW PLG2) Remove the LH-IG fuse from the cowl side J/B LH. Remove the GLW PLG1 and GLW PLG2 fuses from the engine room R/B and J/B No. 1. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Item Condition Specified Condition LH-IG fuse Always Below 1 ohms GLW PLG1 fuse Always Below 1 ohms GLW PLG2 fuse Always Below 1 ohms NG: REPLACE FUSE OK: Go To Next Step
2. INSPECT RELAY (GLW RLY1, GLW RLY2) Remove the GLW RLY1 and GLW RLY2 relays from the engine room R/B and J/B No. 1. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition 3 -- 5 Always 10 kohms or higher 3 -- 5 When battery voltage is applied to terminals 1 and 2 Below 1 ohms NG: REPLACE RELAY OK: Go To Next Step
3. CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER - BATTERY) Disconnect the connector from the A/C amplifier. Turn the engine switch on (IG). Measure the voltage according to the value(s) in the table below. Standard voltage VOLTAGE SPECIFICATION Tester Connection (Symbols) Condition Specified Condition J58-4 (HTR2) - Body ground Engine switch on (IG) 10 to 14 V J58-23 (HTR1) - Body ground Engine switch on (IG) 10 to 14 V NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go To Next Step
4. INSPECT AIR CONDITIONING AMPLIFIER Reconnect the connector to the A/C amplifier. Measure the voltage according to the value(s) in the table below. Standard voltage VOLTAGE SPECIFICATION Tester Connection Condition Specified Condition J58-4 (HTR2) - Body ground Engine switch on (IG) 10 to 14 V J58-4 (HTR2) - Body ground Engine switch on (IG) While the PTC operating conditions are met (engine is running at 850 rpm or more, ambient temperature is 0°C (32°F) or less, engine coolant temperature is 69°C (156°F) or less, and A/C switch setting is MAX HOT), turn the blower switch to the LO setting. Below 1 V J58-23 (HTR1) - Body ground Engine switch on (IG) 10 to 14 V D47-2 - Body ground Engine switch on (IG) While the PTC operating conditions are met (engine is running at 850 rpm or more, ambient temperature is 0°C (32°F) or less, engine coolant temperature is 69°C (156°F) or less, and A/C switch setting is MAX HOT), turn the blower switch to the LO setting. Below 1 V NG: REPLACE AIR CONDITIONING AMPLIFIER OK: Go to next step
5. INSPECT HEATER BLOWER WIRE Remove the grommets and nuts of the water by-pass glow plugs. Turn the engine switch on (IG). Perform ACTIVE TEST by referring to the table below. AIR CONDITIONER: AIR CONDITIONER Item Test Details / Display (Range) Diagnostic Note HEATER 1 (Electric Heater 1) Electric Heater 1 / OFF, ON - HEATER 2 (Electric Heater 2) Electric Heater 2 / OFF, ON - Measure the voltage according to the value(s) in the table below. Standard voltage VOLTAGE SPECIFICATION Tester Connection Condition Specified Condition 1 - Body ground Perform ACTIVE TEST / HEATER 1 (Electric Heater 1): ON 10 to 14 V 2 - Body ground Perform ACTIVE TEST / HEATER 2 (Electric Heater 2): ON 10 to 14 V NG: REPAIR OR REPLACE HEATER BLOWER WIRE OK: Go To Next Step
6. INSPECT WATER BY-PASS GLOW PLUG Remove the water by-pass glow plug. Measure the resistance according to the value(s) in the table below. Standard resistance: Below 1 ohms NG: REPLACE WATER BY-PASS GLOW PLUG OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

The low pressure sensor reduces the capacity of the compressor when the compressor is operating at high speed. This sensor monitors the pressure on the low pressure side at terminal CUT+ and sends a signal to terminal PSW of the A/C amplifier, which increases the accuracy of compressor control.

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1. CHECK REFRIGERANT PRESSURE Check the sight glass of the cooler unit refrigerant liquid pipe. Prepare the vehicle according to the chart below. ITEM CONDITION Item Condition Vehicle Doors Fully open Temperature Setting MAX COLD Blower Speed HI A/C ON Compare the sight glass to the following chart. SYMPTOM CHART Item Symptom Amount of Refrigerant Corrective Actions 1 Bubbles visible Insufficient (1) Check for gas leakage and repair if necessary Add refrigerant until bubbles disappear 2 No bubbles visible Empty, insufficient, or excessive Refer to 3 and 4 3 No temperature difference between compressor inlet and outlet Empty or nearly empty Check for gas leakage with gas leak detector and repair if necessary Evacuate A/C system and recharge with proper amount of refrigerant 4 Considerable temperature difference between compressor inlet and outlet Proper or excessive Refer to 5 and 6 5 Immediately after air conditioning is turned OFF, refrigerant clears Excessive Recover refrigerant Evacuate A/C system and recharge with proper amount of refrigerant 6 Immediately after air conditioning is turned OFF, refrigerant foams and then becomes clear Proper - (1) Bubbles in the sight glass with the vehicle interior temperature above 35°C (95°F) can be considered normal if cooling is sufficient. NG: CHARGE REFRIGERANT OK: Go to next step
2. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - LOW PRESSURE SENSOR) Disconnect the pressure sensor connector. Disconnect the A/C amplifier connector. Measure the resistance according to the value(s) in the table below. RESISTANCE SPECIFICATION Tester Connection (Symbols) Condition Specified Condition J58-18 (SG-3) - A56-1 (-S) Always Below 1 ohms J58-27 (S5-3) - A56-3 (+S) Always Below 1 ohms J58-32 (PSW) - A56-2 (CUT+) Always Below 1 ohms J58-18 (SG-3) - Body ground Always 10 kohms or higher J58-27 (S5-3) - Body ground Always 10 kohms or higher J58-32 (PSW) - Body ground Always 10 kohms or higher NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go To Next Step
3. INSPECT LOW PRESSURE SENSOR Install the manifold gauge set (See «ON-VEHICLE INSPECTION»(ref-235579-S02659531892006062400000) ). Connect the three 1.5 V dry cell batterie's positive (+) lead to terminal 3 and the negative (-) lead to terminal 1. Then connect the voltmeter's positive (+) lead to terminal 2 and the negative (-) lead to terminal 1. Measure the voltage. OK: The voltage changes according to refrigerant pressure, as shown in the graph. NG: REPLACE LOW PRESSURE SENSOR OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

The main power source is supplied to the A/C amplifier when the engine switch on (IG).

The power source is used for operating the A/C amplifier and servo motor, etc.

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HINT

Start the engine before inspection. Check the IG1 relay or battery if the engine does not start.

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1. INSPECT FUSE (ECU-IG LH) Remove the ECU-IG LH fuse from the cowl side junction block LH. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Item Condition Specified Condition ECU-IG LH fuse Always Below 1 ohms NG: REPLACE FUSE (ECU-IG LH) OK: Go To Next Step
2. INSPECT AIR CONDITIONING AMPLIFIER (IG+ - GND) Remove the A/C amplifier 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 VOLTAGE SPECIFICATION Tester Connection Condition Specified Condition J58-21 (IG+) - J58-20 (GND) Engine switch on (IG) 10 to 14 V NG: Go to step 3 OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
3. CHECK WIRE HARNESS (AIR CONDITIONING AMPLIFIER - BATTERY) Disconnect the A/C amplifier connector. Measure the voltage according to the value(s) in the table below. Standard voltage VOLTAGE SPECIFICATION Tester Connection Condition Specified Condition J58-21 (IG+) - Body ground Engine switch off Below 1 V Engine switch on (IG) 10 to 14 V NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go To Next Step
4. CHECK WIRE HARNESS (AIR CONDITIONING AMPLIFIER - BODY GROUND) Disconnect the A/C amplifier connector. Measure the resistance according to the value(s) in the table below. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition J58-20 (GND) - Body ground Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE AIR CONDITIONING AMPLIFIER

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

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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 RESISTANCE SPECIFICATION Tester Item Condition Specified Condition A/C fuse Always Below 1 ohms NG: REPLACE FUSE (A/C) OK: Go To Next Step
2. INSPECT AIR CONDITIONING AMPLIFIER (AIR CONDITIONING AMPLIFIER - BODY GROUND) Disconnect the A/C amplifier connector. Measure the voltage according to the value(s) in the table below. Standard voltage VOLTAGE SPECIFICATION Tester Connection Condition Specified Condition J58-1 (B) - Body ground Always 10 to 14 V NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

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1. INSPECT REFRIGERANT VOLUME Check the sight glass on the liquid tube subassembly. Test conditions: Engine is running at 1,500 rpm. Blower speed control switch is at HI. A/C switch is ON. Temperature control switch is at MAX. COOL. Doors are fully open. SYMPTOM CHART Item Symptom Amount of Refrigerant Corrective Procedures 1 Bubbles visible Insufficient (1) Check for gas leakage and repair if necessary Add refrigerant until bubbles disappear 2 No bubbles visible Empty, insufficient or too much Refer to items 3 and 4 3 No temperature difference between compressor inlet and outlet Empty or nearly empty Check for gas leakage with gas leak detector and repair if necessary Add refrigerant until bubbles disappear 4 Considerable temperature difference between compressor inlet and outlet Correct or too much Refer to items 5 and 6 5 Immediately after A/C is turned OFF, refrigerant becomes clear Too much Drain or discharge refrigerant Bleed air and supply proper amount of purified refrigerant 6 Immediately after A/C is turned OFF, refrigerant foams and then becomes clear Correct - HINT: (1) If the ambient temperature is higher than usual but cooling is sufficient, bubbles in the sight glass are permissible.
2. INSPECT REFRIGERANT PRESSURE WITH MANIFOLD GAUGE SET This method uses a manifold gauge set to locate problem areas. Read the manifold gauge pressure when the following conditions are established. Test conditions: Temperature at the air inlet is 30 to 35°C (86 to 95°F). Engine is running at 1,500 rpm. All doors are fully open. Blower speed control switch is at HI. Temperature control switch is at MAX. COOL. A/C switch is ON. Gauge readings (Reference) Normally functioning refrigeration system Gauge reading GAUGE READING REFERENCE Pressure side Refrigerant volume Low 0.15 to 0.25 MPa (1.5 to 2.5 kgf/cm 2 ) High 1.37 to 1.57 MPa (14 to 16 kgf/cm 2 ) The A/C system periodically changes between normal and improper function due to moisture in the refrigeration system. PROBABLE SYMPTOMS CHART Symptoms Probable Cause Diagnosis Corrective Actions During operation, pressure on low - pressure side cycles between normal and vacuum Moisture in refrigeration system freezes at expansion valve orifice, causing temporary stop of cycle. However, when melted, normal state is restored Drier is oversaturated Moisture in refrigeration system freezes at expansion valve orifice and blocks refrigerant circulation Replace cooler drier Remove moisture from cycle by repeatedly evacuating air Supply appropriate volume of new refrigerant The A/C system does not function effectively due to insufficient cooling. PROBABLE SYMPTOMS CHART Symptoms Probable Cause Diagnosis Corrective Actions Pressure low on both low and high-pressure sides Cooling performance insufficient Gas leakage from refrigeration system Insufficient refrigerant Refrigerant leakage Check for gas leakage and repair if necessary Supply appropriate volume of new refrigerant If indicated pressure value is close to 0 when connected to gauge, create vacuum after inspecting and repairing the location of leakage The A/C system does not function effectively due to poor circulation of the refrigerant. PROBABLE SYMPTOMS CHART Symptoms Probable Cause Diagnosis Corrective Actions Pressure low on both low and high-pressure sides Frost exists on piping from condenser to A/C unit Refrigerant flow obstructed by dirt in condenser Condenser clogged Replace condenser The A/C system does not function intermittently because the refrigerant does not circulate. PROBABLE SYMPTOMS CHART Symptoms Probable Cause Diagnosis Corrective Actions Vacuum indicated on lowpressure side, and extremely low pressure indicated on highpressure side Frost or condensation seen on piping on both sides of condenser or expansion valve Refrigerant flow obstructed by moisture or dirt in refrigeration system Refrigerant flow obstructed by gas leakage from expansion valve Refrigerant does not circulate Check expansion valve Clean expansion valve by blowing air Replace condenser Evacuate air and charge appropriate volume of new refrigerant For gas leakage from expansion valve, replace expansion valve The A/C system does not function effectively due to overcharged refrigerant or insufficient cooling of the condenser. PROBABLE SYMPTOMS CHART Symptoms Probable Cause Diagnosis Corrective Actions Pressure extremely high on both low and high-pressure sides Excessive refrigerant Cooling performance of condenser insufficient Condenser is dirty Condenser fan motor is malfunctioning Excessive refrigerant Clean condenser Check condenser fan motor operation If 1 and 2 are normal, check the amount of refrigerant and supply appropriate volume of refrigerant The A/C system does not function due to air in the refrigeration system. CAUTION: The low-pressure piping may be very hot and cause serious burns. PROBABLE SYMPTOMS CHART Symptoms Probable Cause Diagnosis Corrective Actions Pressure extremely high on both low and high-pressure sides The low-pressure piping is too hot to touch Air in refrigeration system Air in refrigeration system Vacuum purging insufficient Check if compressor oil is dirty or insufficient Evacuate air and charge new refrigerant The A/C system does not function effectively due to an expansion valve malfunction. PROBABLE SYMPTOMS CHART Symptoms Probable Cause Diagnosis Corrective Actions Pressure extremely high on both low and high-pressure sides Frost or condensation on piping on low-pressure side Problem with expansion valve Excessive refrigerant in low pressure piping Expansion valve too wide open Replace expansion valve The A/C system does not function due to a defective compressor. PROBABLE SYMPTOMS CHART Symptoms Probable Cause Diagnosis Corrective Actions Pressure extremely high on both low and high-pressure sides Pressure extremely low on highpressure side Internal leakage in compressor Compression failure Leakage from damaged valve or broken sliding parts Repair or replace compressor

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