INSPECTION
Before performing the diagnosis, check the following items which may cause problems in the A/C system.
A/C CONTROL PANEL SELF-DIAGNOSIS
| Step | Check | Yes | No |
|---|---|---|---|
| 1 PERFORM A/C CONTROL PANEL SELF-DIAGNOSIS FUNCTION. Turn the ignition switch to OFF. Turn the ignition switch to ON with the AUTO switch and MODE switch pressed at the same time. All the screen display illuminate (for approx. 5 seconds) and the self-diagnosis mode starts. | Does the self-diagnosis function operate? | Go to step 2. | < Ref. to A/C OR SELF-DIAGNOSIS SYSTEMS DO NOT OPERATE, Diagnostics for A/C System Malfunction. > |
| 2 CHECK SCREEN DISPLAY. Check the illumination condition while the display is illuminated. | Does all the screen display and indicators illuminate? | Go to step 3. | Replace the A/C control panel. |
| 3 CHECK SCREEN DISPLAY. After the illumination ends, check the display. | Are the numbers 11 -14 displayed at the setting temperature display area? | Go to step 5. | Go to step 4. |
| 4 CHECK SWITCH AND TEMPERATURE CONTROL DIAL INPUT. Operate each switch or dial according to the switch check table. Check the display or indicator illumination condition when operating the switch or dial. < Ref. to SWITCH CHECK TABLE, OPERATION, Diagnostic Chart for Self-diagnosis. > | Does the input of each switch or dial correspond to the switch check list? | Go to step 5. | Replace the heater control panel. |
| 5 CHECK A/C CONTROL PANEL COMMUNICATION. Turn the ignition switch to OFF. Disconnect the connector of the auto A/C control module. Using a suitable lead wire, short the terminal No. 34 and No. 35 of auto A/C control module vehicle side connector (B282). Turn the ignition switch to ON with the A/C switch and AUTO switch pressed at the same time. Check the screen display when operating each switch and dial. | Is "CL" displayed on the screen when operating each switch and dial? | Go to step 6. | Go to step 7. |
| 6 CHECK A/C CONTROL PANEL COMMUNICATION. Turn the ignition switch to OFF. Disconnect the lead wire used to short the terminals. Turn the ignition switch to ON with the A/C switch and AUTO switch pressed at the same time. Check the screen display when operating each switch and dial. | Is "OP" displayed on the screen when operating each switch and dial? | A/C control panel and body harness are normal. | Go to step 7. |
| 7 CHECK HARNESS. Turn the ignition switch to OFF. Disconnect the A/C control panel connector (i88). Measure the resistance between connectors with a tester. Connector & terminal (i88) No. 7 - (B282) No. 34: (i88) No. 3 - (B282) No. 35 | Is the resistance less than 10 ohms? | Go to step 8. | Repair the open circuit of the harness between A/C control panel and auto A/C control module. |
| 8 CHECK HARNESS. Measure the resistance between connectors with a tester. Connector & terminal (i88) No. 7 - No. 3 | Is the resistance less than 10 ohms? | Repair the short circuit of the harness between A/C control panel and auto A/C control module. | Replace the A/C control panel. |
DIAGNOSTIC PROCEDURE CHART
Scheme 132
| Switch | Display screen | Switch | Display screen |
|---|---|---|---|
| A/C switch | (6) | FAN switch (+) | (4) |
| AUTO switch | (1) | FAN switch (-) | (3) |
| Air flow control switch | (9) | Driver's side temperature control dial | (9), (10), (12) |
| FRESH/RECIRC | (13) | Passenger's side temperature control dial | (9), (11), (12) |
| Defroster switch | (7), (12) | OFF switch | (2), (5) |
| Rear defogger switch | (8) |
SCREEN DISPLAY CHART
A/C CONTROL SYSTEM SELF-DIAGNOSIS
| Step | Check | Yes | No |
|---|---|---|---|
| 1 SET SELF-DIAGNOSIS MODE BY OPERATING A/C CONTROL PANEL. Start the engine with the A/C switch and front defroster switch pressed. NOTE: Self-diagnosis can also be performed with ignition switch On, but start the engine because observing the magnet clutch operation is difficult. All the indicators blink four times. | Does the self-diagnosis function operate? | Go to step 2. | < Ref. to A/C OR SELF-DIAGNOSIS SYSTEMS DO NOT OPERATE, Diagnostics for A/C System Malfunction. > |
| 2 CHECK EACH SENSOR AND POTENTIOMETER. After the indicators stop blinking, automatically change to the Inspection Mode of sensor and potentiometer. NOTE: Display items can be changed each time the A/C switch is pressed. (Step Operation) When malfunction occurs in each sensor and potentiometer, codes are displayed on the screen. When no malfunction occurs in each sensor and potentiometer, code "20" is displayed on the screen. Identify the defective sensor according to the sensor check table. < Ref. to SENSOR CHECK TABLE, OPERATION, Diagnostic Chart for Self-diagnosis. > | Are other codes except "20" displayed? | Repair the defective sensor. < Ref. to DIAGNOSTIC PROCEDURE FOR SENSORS. > | Go to step 3. |
| 3 CHECK EACH ACTUATOR, BLOWER FAN AND MAGNET CLUTCH. After completing each sensor and potentiometer inspection, change to the Inspection Mode of actuator, blower fan and magnet clutch by pressing the defroster switch. Each mode will change and operate automatically every four seconds. NOTE: Operation mode items can be changed each time the A/C switch is pressed. (Step Operation) Check the operation of actuator, blower fan and magnet clutch in each mode according to the operating mode table. < Ref. to OPERATING MODE TABLE, OPERATION, Diagnostic Chart for Self-diagnosis. > | Do the actuator, blower fan and magnet clutch operate as described in the operating mode table? | A/C control system is normal. Press the OFF switch and complete the self-diagnosis function. | Repair the defective part in accordance with each diagnostic chart. < Ref. to DIAGNOSTICS FOR A/C SYSTEM MALFUNCTION. > or < Ref. to DIAGNOSTIC PROCEDURE FOR ACTUATORS. > |
| NOTE |
|---|
| Self-diagnosis can also be performed with ignition switch On, but start the engine because observing the magnet clutch operation is difficult. |
| NOTE |
|---|
| Display items can be changed each time the A/C switch is pressed. (Step Operation) |
| NOTE |
|---|
| Operation mode items can be changed each time the A/C switch is pressed. (Step Operation) |
DIAGNOSTIC PROCEDURE CHART
TROUBLE SYMPTOM
- Set temperature is not indicated on the display, switch LEDs are faulty and switches do not operate.
- Self-diagnosis system does not operate.
Scheme 133
| Step | Check | Yes | No |
|---|---|---|---|
| 1 CHECK FUSE. Turn the ignition switch to OFF. Remove the fuse No. 7 from main fuse box. Check the condition of fuse. | Is the fuse blown out? | Replace the fuse. | Go to step 2. |
| 2 CHECK FUSE. Turn the ignition switch to OFF. Remove the fuse No. 22 from the fuse & relay box. Check the condition of fuse. | Is the fuse blown out? | Replace the fuse. | Go to step 3. |
| 3 CHECK A/C CONTROL PANEL POWER CIRCUIT. Measure the voltage between A/C control panel harness connector terminal and chassis ground after turning the ignition switch to ON. Connector & terminal (i88) No. 1 (+) - Chassis ground (-) | Is the voltage 10 V or more? | Go to step 4. | Check for open or short circuit in the harness between A/C control panel and fuse. |
| 4 CHECK A/C CONTROL PANEL GROUND POWER CIRCUIT. Measure the resistance of harness between A/C control panel and chassis ground after turning the ignition switch to OFF. Connector & terminal (i88) No. 5 - Chassis ground | Is resistance less than 10 ohms? | Go to step 5. | Repair the harness for ground line. |
| 5 CHECK AUTO A/C CONTROL MODULE POWER CIRCUIT. Measure the voltage between auto A/C control module connector terminal and chassis ground after turning the ignition switch to OFF. Connector & terminal (B282) No. 1 (+) - Chassis ground (-) | Is the voltage 10 V or more? | Go to step 6. | Check open or short circuit of harness between auto A/C control module and fuse. |
| 6 CHECK AUTO A/C CONTROL MODULE POWER CIRCUIT. Measure the voltage between auto A/C control module connector terminal and chassis ground after turning the ignition switch to the ON position. Connector & terminal (B282) No. 21 (+) - Chassis ground (-) | Is the voltage 10 V or more? | Go to step 7. | Check open or short circuit of harness between auto A/C control module and fuse. |
| 7 CHECK AUTO A/C CONTROL MODULE GROUND CIRCUIT. Measure the resistance of harness between auto A/C control module and chassis ground. Connector & terminal (B282) No. 28 - Chassis ground | Is resistance less than 5 ohms? | Go to step 8. | Repair the harness for ground line. |
| 8 CHECK COMMUNICATION CIRCUIT. Measure the resistance of harness between A/C control panel and auto A/C control module. Connector & terminal (i88) No. 3 - (B282) No. 35: (i88) No. 7 - (B282) No. 34 | Is the resistance less than 1 ohms? | Go to step 9. | Repair the harness. |
| 9 CHECK POOR CONTACT. Check poor contact of auto A/C control module connector. | Is there poor contact in connector? | Repair the connector. | Replace the auto A/C control module. |
DIAGNOSTIC PROCEDURE CHART
- Blower motor does not rotate.
- Blower motor does not rotate in "HI".
Scheme 134
| Step | Check | Yes | No |
|---|---|---|---|
| 1 CHECK FUSE. Remove fuse No. 22, 27 and 28 from fuse & relay box. Check the condition of fuse. | Is any fuse blown out? | Replace the fuse. | Go to step 2. |
| 2 CHECK POWER SUPPLY FOR BLOWER MOTOR. Turn the ignition switch to ON. Turn the blower switch to ON. Measure the voltage between blower motor and chassis ground. Connector & terminal (B87) No. 2 (+) - Chassis ground (-) | Is the voltage 10 V or more? | Go to step 3. | Repair the open circuit of blower motor power supply line harness. |
| 3 CHECK BLOWER MOTOR RELAY. Turn the ignition switch to OFF. Remove the blower motor relay. Connect the battery positive (+) terminal to terminal No. 23 of blower motor relay, and negative (-) terminal to terminal No. 24. Measure the resistance between terminals No. 21 and No. 22. Terminals (B225) No. 21 - (B225) No. 22 | Is resistance less than 1 ohms? | Go to step 4. | Replace the blower motor relay. |
| 4 CHECK BLOWER MOTOR. Disconnect the connector from the blower motor. Connect the battery positive (+) terminal to terminal No. 2 of blower motor connector, and negative (-) terminal to terminal No. 1. Make sure the blower motor runs. | Does the blower motor run? | Go to step 5. | Replace the blower motor. |
| 5 CHECK POOR CONTACT. Check poor contact of auto A/C control module connector. | Is there poor contact in connector? | Repair the connector. | Replace the auto A/C control module. |
DIAGNOSTIC PROCEDURE CHART
Scheme 135
| Step | Check | Yes | No |
|---|---|---|---|
| 1 CHECK FUSE. Turn the ignition switch to OFF. Remove the fuse No. 22 from fuse & relay box. Check the condition of fuse. | Is the fuse blown out? | Replace the fuse. | Go to step 2. |
| 2 CHECK POWER SUPPLY TO A/C RELAY AND AUTO A/C CONTROL MODULE. Disconnect the A/C relay and auto A/C control module harness connector. Turn the ignition switch to ON. Measure the voltage between A/C relay connector terminal and chassis ground. Measure the voltage between auto A/C control module harness connector terminal and chassis ground. Connector & terminal (F27) No. 17(+) - Chassis ground (-): (B282) No. 22 (+) - Chassis ground (-) | Is the voltage 10 V or more? | Go to step 5. | Go to step 3. |
| 3 CHECK POWER SUPPLY FOR PRESSURE SWITCH. Turn the ignition switch to OFF. Disconnect the pressure switch harness connector. Turn the ignition switch to ON. Measure the voltage between pressure switch harness connector terminal and chassis ground. Connector & terminal (B10) No. 2 (+) - Chassis ground (-) | Is the voltage 10 V or more? | Go to step 4. | Check for open or short circuit in the harness between fuse and pressure switch. |
| 4 CHECK HARNESS BETWEEN PRESSURE SWITCH AND A/C RELAY, AUTO A/C CONTROL MODULE. Turn the ignition switch to OFF. Measure the resistance of harness between pressure switch connector and A/C relay connector. Measure the resistance of harness between pressure switch connector and auto A/C control module connector. Connector & terminal (B10) No. 1 - (F27) No. 17: (B10) No. 1 - (B282) No. 22 | Is the resistance less than 1 ohms? | Check the pressure switch. < Ref. to Pressure Switch (Triple Pressure Switch) INSPECTION. > | Repair the harness. |
| 5 CHECK POWER SUPPLY FOR A/C RELAY. Measure the voltage between A/C relay connector terminal and chassis ground. Connector & terminal (F27) No. 14 (+) - Chassis ground (-) | Is the voltage 10 V or more? | Go to step 6. | Check open or short circuit of harness between fuse and A/C relay. |
| 6 CHECK A/C RELAY. Check the A/C relay. < Ref. to Relay and Fuse INSPECTION. > | Is there a malfunction in the A/C relay? | Replace the A/C relay. | Go to step 7. |
| 7 CHECK A/C ON SIGNAL. Turn the ignition switch to OFF. Connect the A/C relay and all disconnected connectors. Start the engine and turn the AUTO switch to ON. Turn the temperature control dial at maximum cool position. Measure the voltage between auto A/C control module harness connector terminal and chassis ground. Connector & terminal (B282) No. 15 (+) - Chassis ground (-) | Is the voltage 5.5 V or more? | Go to step 9. | Go to step 8. |
| 8 CHECK HARNESS BETWEEN AUTO A/C CONTROL MODULE AND ECM. Turn the ignition switch to OFF. Disconnect the harness connector of auto A/C control module and ECM. Measure the resistance of harness between auto A/C control module connector and ECM connector. Connector & terminal (B282) No. 15 - (B136) No. 24 | Is the resistance less than 1 ohms? | Replace the auto A/C control module. | Repair the harness. |
| 9 CHECK MAGNET CLUTCH ON SIGNAL. Stop the engine, and turn the AUTO switch to OFF. Turn the ignition switch to ON. Measure the voltage between ECM connector terminal and chassis ground. Connector & terminal (B136) No. 9 (+) - Chassis ground (-) | Is the voltage 10 V or more? | Go to step 10 . | Check for open or short circuit in the harness between A/C relay and ECM. |
| 10 CHECK MAGNET CLUTCH ON SIGNAL. Start the engine and turn the AUTO switch to ON. Turn the temperature control dial at maximum cool position. Measure the voltage between ECM connector terminal and chassis ground. Connector & terminal (B136) No. 9 (+) - Chassis ground (-) | Is the voltage 0 V? | Go to step 11 . | Replace the ECM. |
| 11 CHECK POWER SUPPLY FOR MAGNET CLUTCH. Stop the engine, and turn the AUTO switch to OFF. Disconnect the harness connector of magnet clutch. Start the engine and turn the AUTO switch to ON. Turn the temperature control dial at maximum cool position. Measure the voltage between magnet clutch harness connector terminal and chassis ground. Connector & terminal (F24) No. 1 (+) - Chassis ground (-) | Is the voltage 10 V or more? | Go to step 12 . | Check for open or short circuit in the harness between A/C relay and magnet clutch. |
| 12 CHECK HARNESS BETWEEN AUTO A/C CONTROL MODULE AND ECM. Stop the engine, and turn the AUTO switch to OFF. Measure the resistance between magnet clutch harness connector terminal and chassis ground. Connector & terminal (F24) No. 2 - Chassis ground | Is the resistance less than 1 ohms? | Inspect the compressor. < Ref. to Compressor INSPECTION. > | Repair the harness. |
DIAGNOSTIC PROCEDURE CHART
FRESH/RECIRC mode is not changed.
Scheme 136
| Step | Check | Yes | No |
|---|---|---|---|
| 1 CHECK POWER SUPPLY FOR INTAKE DOOR ACTUATOR. Turn the ignition switch to OFF. Disconnect the intake door actuator connector. Turn the ignition switch to ON. Measure the voltage between intake door actuator connector and chassis ground. Connector & terminal (B91) No. 7 (+) - Chassis ground (-) | Is the voltage 7 V (at normal temperature)? | Go to step 2. | Check for open or short circuit in the harness between intake door actuator and fuse. |
| 2 CHECK HARNESS BETWEEN AUTO A/C CONTROL MODULE AND INTAKE DOOR ACTUATOR. Turn the ignition switch to OFF. Disconnect the auto A/C control module connector. Measure the resistance between intake door actuator connector and auto A/C control module connector. Connector & terminal (B282) No. 20 - (B91) No. 3: (B282) No. 40 - (B91) No. 1 | Is the resistance less than 1 ohms? | Go to step 3. | Repair the harness between auto A/C control module and intake door actuator. |
| 3 CHECK OPERATION OF INTAKE DOOR ACTUATOR. Connect the intake door actuator connector. Ground the auto A/C control module connector with a suitable wire. Turn the ignition switch to ON, and check the operation of intake door actuator. Connector & terminal (B282) No. 20 - Chassis ground | Does the actuator move to the FRESH side? | Go to step 4. | Replace the intake door actuator. |
| 4 CHECK OPERATION OF INTAKE DOOR ACTUATOR. Turn the ignition switch to OFF. Ground the auto A/C control module connector with a suitable wire. Turn the ignition switch to ON, and check the operation of intake door actuator. Connector & terminal: (B282) No. 40 - Chassis ground | Does the actuator move to the RECIRC side? | Replace the auto A/C control module. | Replace the intake door actuator. |
DIAGNOSTIC PROCEDURE CHART
Air flow outlet is not changed.
Scheme 137
| Step | Check | Yes | No |
|---|---|---|---|
| 1 CHECK POWER SUPPLY FOR MODE DOOR ACTUATOR POSITION SENSOR. Turn the ignition switch to OFF. Disconnect the mode door actuator connector. Turn the ignition switch and AUTO switch to ON. Measure the voltage between auto A/C control module connector terminals. Connector & terminal (B282) No. 8 (+) - (B282) No. 27 (-) | Is the voltage approx. 5 V? | Go to step 2. | Replace the auto A/C control module. |
| 2 CHECK POWER SUPPLY FOR MODE DOOR ACTUATOR. Measure the voltage between auto A/C control module connector and chassis ground after turning the air flow control switch to FACE position. Connector & terminal (B282) No. 16 (+) - Chassis ground (-) | Is the voltage 7 V (at normal temperature)? | Go to step 3. | Replace the auto A/C control module. |
| 3 CHECK POWER SUPPLY FOR MODE DOOR ACTUATOR. Measure the voltage between auto A/C control module connector and chassis ground after turning the air flow control switch to DEF position. Connector & terminal (B282) No. 36 (+) - Chassis ground (-) | Is the voltage 7 V (at normal temperature)? | Go to step 4. | Replace the auto A/C control module. |
| 4 CHECK HARNESS BETWEEN AUTO A/C CONTROL MODULE AND MODE DOOR ACTUATOR. Turn the A/C and ignition switch to OFF. Disconnect the auto A/C control module connector. Measure the resistance between auto A/C control module and mode door actuator connector. Connector & terminal (B77) No. 1 - (B282) No. 27: (B77) No. 3 - (B282) No. 8: (B77) No. 5 - (B282) No. 3: (B77) No. 6 - (B282) No. 36: (B77) No. 7 - (B282) No. 16 | Is the resistance less than 1 ohms? | Go to step 5. | Repair the harness between auto A/C control module and mode door actuator. |
| 5 CHECK MODE DOOR ACTUATOR POSITION SWITCH SIGNAL. Connect the connector of auto A/C control module and mode door actuator. Turn the ignition switch and AUTO switch to ON. Check the voltage between auto A/C control module connector terminals while changing the mode between DEF and FACE. Connector & terminal (B282) No. 3 (+) - (B282) No. 27 (-) | Does the voltage change between 1 V (DEF) and 4 V (FACE)? | Go to step 6. | Replace the mode door actuator. |
| 6 CHECK POOR CONTACT. Check poor contact of auto A/C control module and connector. | Is there poor contact in connector? | Repair the connector. | Replace the auto A/C control module. |
DIAGNOSTIC PROCEDURE CHART
Outlet air temperature does not change.
Scheme 138
| Step | Check | Yes | No |
|---|---|---|---|
| 1 CHECK POWER SUPPLY FOR AIR MIX DOOR ACTUATOR POSITION SWITCH. Turn the ignition switch to OFF. Disconnect the air mix door actuator connector. Turn the ignition switch and AUTO switch to ON. Measure the voltage between auto A/C control module connector terminals. Connector & terminal (B282) No. 8 (+) - (B282) No. 27 (-) | Is the voltage approx. 5 V? | Go to step 2. | Replace the auto A/C control module. |
| 2 CHECK POWER SUPPLY FOR AIR MIX DOOR ACTUATOR. Measure the voltage between auto A/C control module connector and chassis ground after turning the temperature control dial to maximum COOL position. Connector & terminal Driver's side (B282) No. 18 (+) - Chassis ground (-): Passenger's side (B282) No. 17 (+) - Chassis ground (-) | Is the voltage 7 V (at normal temperature)? | Go to step 3. | Replace the auto A/C control module. |
| 3 CHECK POWER SUPPLY FOR AIR MIX DOOR ACTUATOR. Measure the voltage between auto A/C control module connector and chassis ground after turning the temperature control dial to maximum HOT position. Connector & terminal Driver's side (B282) No. 38 (+) - Chassis ground (-): Passenger's side (B282) No. 37 (+) - Chassis ground (-) | Is the voltage 7 V (at normal temperature)? | Go to step 4. | Replace the auto A/C control module. |
| 4 CHECK HARNESS BETWEEN AUTO A/C CONTROL MODULE AND AIR MIX DOOR ACTUATOR. Turn the A/C and ignition switch to OFF. Disconnect the auto A/C control module connector. Measure the resistance between auto A/C control module and air mix door actuator connector. Connector & terminal Driver's side (B390) No. 1 - (B282) No. 27: (B390) No. 3 - (B282) No. 8: (B390) No. 5 - (B282) No. 24: (B390) No. 6 - (B282) No. 38: (B390) No. 7 - (B282) No. 18: Passenger's side (B235) No. 1 - (B282) No. 8: (B235) No. 3 - (B282) No. 27: (B235) No. 5 - (B282) No. 4: (B235) No. 6 - (B282) No. 17: (B235) No. 7 - (B282) No. 37 | Is the resistance less than 1 ohms? | Go to step 5. | Repair the harness between auto A/C control module and air mix door actuator. |
| 5 CHECK AIR MIX DOOR ACTUATOR POSITION SWITCH SIGNAL. Connect the connector of auto A/C control module and air mix door actuator. Turn the ignition switch and AUTO switch to ON. Check the voltage between auto A/C control module connector terminals while changing the setting temperature between maximum COOL and maximum HOT. Connector & terminal Driver's aide (B282) No. 24 (+) - (B282) No. 27 (-): Passenger's side (B282) No. 4 (+) - (B282) No. 27 (-) | Does the voltage change between 1 V (Max. HOT) and 4 V (Max. COOL)? | Go to step 6. | Replace the air mix door actuator. |
| 6 CHECK POOR CONTACT. Check poor contact of auto A/C control module and connector. | Is there poor contact in connector? | Repair the connector. | Replace the auto A/C control module. |
DIAGNOSTIC PROCEDURE CHART
Fan speed is not switched when the fan speed control dial is in AUTO position.
Scheme 139
| Step | Check | Yes | No |
|---|---|---|---|
| 1 CHECK AMBIENT SENSOR. Turn the ignition switch to OFF. Disconnect the connector from ambient sensor. Measure the resistance between connector terminals of ambient sensor. Terminals No. 1 - No. 2 | Is the resistance approximately 2.2 kohms at 25°C (77°F)? | Go to step 2. | Replace the ambient sensor. |
| 2 CHECK INPUT SIGNAL FOR AMBIENT SENSOR. Turn the ignition to ON. Measure the voltage between connector (F78) terminals. Connector & terminal (F78) No. 1 (+) - No. 2 (-) | Is the voltage approx. 5 V? | Go to step 6. | Go to step 3. |
| 3 CHECK OUTPUT SIGNAL OF BODY INTEGRATED UNIT. Turn the ignition switch to OFF. Draw out the body integrated unit. Disconnect the connector from ambient sensor. Turn the ignition switch to ON. Measure the voltage between connector terminals of body integrated unit. Connector & terminal (B281) No. 3 (+) - No. 10 (-) | Is the voltage approx. 5 V? | Go to step 4. | Go to step 6. |
| 4 CHECK HARNESS CONNECTOR BETWEEN BODY INTEGRATED UNIT AND AMBIENT SENSOR. Turn the ignition switch to OFF. Disconnect the connector from body integrated unit. Measure the resistance of harness between body integrated unit and ambient sensor. Connector & terminal (F78) No. 1 - (B281) No. 10 | Is the resistance less than 1 ohms? | Go to step 5. | Repair the open circuit of harness between body integrated unit and ambient sensor. |
| 5 CHECK HARNESS CONNECTOR BETWEEN BODY INTEGRATED UNIT AND AMBIENT SENSOR. Measure the resistance of harness between body integrated unit and ambient sensor. Connector & terminal (F78) No. 2 - (B281) No. 3 | Is the resistance less than 1 ohms? | Go to step 6. | Repair the open circuit of harness between body integrated unit and ambient sensor. |
| 6 CHECK DTC. Connect the connectors of body integrated unit and ambient sensor as originally connected. Read the DTC of body integrated unit using Subaru Select Monitor. | Is DTC "U xxx" of CAN communication displayed? | Check the communication circuit. < Ref. to BASIC DIAGNOSTIC PROCEDURE. > | Go to step 7. |
| 7 CHECK POOR CONTACT. Check poor contact of auto A/C control module connector. | Is there poor contact in connector? | Repair the connector. | Replace the auto A/C control module. |
DIAGNOSTIC PROCEDURE CHART
Blower fan speed, outlet port and inlet port do not change after turning the AUTO switch to ON
Scheme 140
| Step | Check | Yes | No |
|---|---|---|---|
| 1 CHECK IN-VEHICLE SENSOR. Turn the ignition switch to OFF. Remove the driver's side lower cover. Disconnect the connector from in-vehicle sensor. Measure the resistance between connector terminals of in-vehicle sensor. Terminals No. 1 - No. 2 | Is the resistance approximately 2.7 kohms at 20°C (68°F)? | Go to step 2. | Replace the in-vehicle sensor. |
| 2 CHECK INPUT SIGNAL FOR IN-VEHICLE SENSOR. Turn the ignition switch to ON. Measure the voltage between in-vehicle sensor harness connector terminal and chassis ground. Connector & terminal (i55) No. 2 (+) - No. 1 (-) | Is the voltage approx. 5 V? | Go to step 6. | Go to step 3. |
| 3 CHECK AUTO A/C CONTROL MODULE OUTPUT SIGNAL. Turn the ignition switch to OFF. Remove the auto A/C control module. Turn the ignition switch to ON. Measure the voltage between connector terminals of auto A/C control module. Connector & terminal (B282) No. 5 (+) - (B282) No. 27 (-) | Is the voltage approx. 5 V? | Go to step 4. | Go to step 6. |
| 4 CHECK HARNESS BETWEEN AUTO A/C CONTROL MODULE AND IN-VEHICLE SENSOR. Turn the ignition switch to OFF. Disconnect the connector from the auto A/C control module. Measure the resistance of harness between auto A/C control module and in-vehicle sensor. Connector & terminal (i55) No. 2 - (B282) No. 5 | Is the resistance less than 1 ohms? | Go to step 5. | Repair the harness between auto A/C control module and in-vehicle sensor. |
| 5 CHECK HARNESS BETWEEN AUTO A/C CONTROL MODULE AND IN-VEHICLE SENSOR. Measure the resistance of harness between auto A/C control module and in-vehicle sensor. Connector & terminal (i55) No. 1 - (B282) No. 27 | Is the resistance less than 1 ohms? | Go to step 6. | Repair the harness between auto A/C control module and in-vehicle sensor. |
| 6 CHECK POOR CONTACT. Check poor contact of auto A/C control module connector. | Is there poor contact in connector? | Repair the connector. | Replace the auto A/C control module. |
DIAGNOSTIC PROCEDURE CHART
Scheme 141
| Step | Check | Yes | No |
|---|---|---|---|
| 1 CHECK EVAPORATOR SENSOR. Turn the ignition switch to OFF. Remove the glove box. Disconnect the connector from evaporator sensor. Measure the resistance between connector terminals of the evaporator sensor. Terminals No. 1 - No. 2 | Is the resistance approximately 3.3 kohms at 20°C (68°F)? | Go to step 2. | Replace the evaporator sensor. |
| 2 CHECK INPUT SIGNAL FOR EVAPORATOR SENSOR. Turn the ignition switch to ON. Measure the voltage between connector (B88) terminal and chassis ground. Connector & terminal (B88) No. 1 (+) - No. 2 (-) | Is the voltage approx. 5 V? | Go to step 6. | Go to step 3. |
| 3 CHECK AUTO A/C CONTROL MODULE OUTPUT SIGNAL. Turn the ignition switch to OFF. Remove the auto A/C control module. Turn the ignition switch to ON. Measure the voltage between connector terminals of auto A/C control module. Connector & terminal (B282) No. 25 (+) - No. 27 (-) | Is the voltage approx. 5 V? | Go to step 4. | Go to step 6. |
| 4 CHECK HARNESS CONNECTOR BETWEEN AUTO A/C CONTROL MODULE AND EVAPORATOR SENSOR. Turn the ignition switch to OFF. Disconnect the connector from the auto A/C control module. Measure the resistance of harness between auto A/C control module and evaporator sensor. Connector & terminal (B88) No. 2 - (B282) No. 27 | Is the resistance less than 1 ohms? | Go to step 5. | Repair the open circuit of harness between auto A/C control module and evaporator sensor. |
| 5 CHECK HARNESS CONNECTOR BETWEEN AUTO A/C CONTROL MODULE AND EVAPORATOR SENSOR. Measure the resistance of harness between auto A/C control module and evaporator sensor. Connector & terminal (B88) No. 1 - (B282) No. 25 | Is the resistance less than 1 ohms? | Go to step 6. | Repair the open circuit of harness between auto A/C control module and evaporator sensor. |
| 6 CHECK POOR CONTACT. Check poor contact of auto A/C control module connector. | Is there poor contact in connector? | Repair the connector. | Replace the auto A/C control module. |
DIAGNOSTIC PROCEDURE CHART
- Sensor identifies that sunlight is at maximum. Then, A/C system is controlled to COOL side.
- Sensor identifies that sunlight is at minimum. Then, A/C system is controlled to HOT side.
Note. When the sunload sensor check is performed indoors or in the shade, it could be diagnosed as having an open circuit. Always check the sunload sensor with the sun shining on it.
Scheme 142
| Step | Check | Yes | No |
|---|---|---|---|
| 1 CHECK POWER SUPPLY VOLTAGE FOR SUNLOAD SENSOR. Turn the ignition switch to OFF. Disconnect the connector from sunload sensor. Turn the ignition switch to ON. Measure the power supply voltage for sun-load sensor. Connector & terminal (i51) No. 1 (+) - No. 2 (-) | Is the voltage approx. 5 V? | Go to step 4. | Go to step 2. |
| 2 CHECK HARNESS CONNECTOR BETWEEN AUTO A/C CONTROL MODULE AND SUNLOAD SENSOR. Turn the ignition switch to OFF. Disconnect the connector from the auto A/C control module. Measure the resistance of the harness between the auto A/C control module and sun-load sensor. Connector & terminal (i51) No. 2 - (B282) No. 6 | Is the resistance less than 1 ohms? | Go to step 3. | Repair the harness between auto A/C control module and sunload sensor. |
| 3 CHECK HARNESS CONNECTOR BETWEEN AUTO A/C CONTROL MODULE AND SUNLOAD SENSOR. Measure the resistance of the harness between the auto A/C control module and sunload sensor. Connector & terminal (i51) No. 1 - (B282) No. 8 | Is the resistance less than 1 ohms? | Go to step 4. | Repair the harness between auto A/C control module and sunload sensor. |
| 4 CHECK INPUT VOLTAGE FOR AUTO A/C CONTROL MODULE. Connect the connectors of sunload sensor and auto A/C control module. Turn the ignition switch to ON. Measure the voltage between connector terminals of auto A/C control module. Connector & terminal (B282) No. 8 (+) - (B282) No. 6 (-) | Is the voltage approx. 2.5 V? | Go to step 5. | Replace the sunload sensor. |
| 5 CHECK POOR CONTACT. Check poor contact of auto A/C control module connector. | Is there poor contact in connector? | Repair the connector. | Replace the auto A/C control module. |
DIAGNOSTIC PROCEDURE CHART
| Symptom | Problem parts |
|---|---|
| A/C system fails to operate. | Fuse (M/B No. 8, F/B No. 22, 31) Connector (Poor contact) Ground Auto A/C control module Blower fan motor Blower fan relay A/C relay Compressor (Magnet clutch) Evaporator sensor |
| Fuse is blown out. | Fuse (M/B No. 8, F/B No. 22, 31) Connector (Poor contact) |
| Illumination cannot dim. | Fuse (M/B No. 8, F/B No. 22, 31) Connector (Poor contact) Auto A/C control module Body integrated unit |
| Blower fan does not rotate or fan speed cannot be controlled. | Fuse (F/B No. 22, 27, 28) Connector (Poor contact) Ground Auto A/C control module Blower fan motor Blower fan relay |
| Unable to switch suction vents. | Connector (Poor contact) Auto A/C control module Intake door actuator |
| Unable to switch vents. | Connector (Poor contact) Auto A/C control module Mode door actuator |
| The compartment temperature does not rise. (Warm air does not come out.) | Connector (Poor contact) Auto A/C control module Air mix door actuator In-vehicle sensor, ambient sensor, evaporator sensor and sunload sensor In-vehicle sensor aspirator hose |
| The compartment temperature does not lower. (Cold air does not come out.) | Connector (Poor contact) Auto A/C control module Air mix door actuator A/C relay Compressor (Magnet clutch) Radiator fan motor Radiator fan relay In-vehicle sensor, ambient sensor, evaporator sensor and sunload sensor In-vehicle sensor aspirator hose |
| Compartment temperature is higher or lower than setting temperature. | Auto A/C control module Air mix door actuator In-vehicle sensor, ambient sensor, evaporator sensor and sunload sensor In-vehicle sensor aspirator hose |
| Compartment temperature does not quickly respond to setting temperature. | Air mix door actuator In-vehicle sensor, ambient sensor, evaporator sensor and sunload sensor In-vehicle sensor aspirator hose |
| Radiator fan does not rotate during A/C operation. | Radiator fan motor Radiator fan relay |
SYMPTOM CHART
See also:
• READ CURRENT DATA FOR ENGINE (NORMAL MODE)