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 SELECT SELF-DIAGNOSIS MODE IN THE CONTROL PANEL. Set the air flow control dial and the fan speed control dial to AUTO. Start the engine with the A/C switch and the FRESH/RECIRC switch pressed. | Does the self-diagnosis mode operate? | Go to step 2. | Refer to A/C OR SELF-DIAGNOSIS SYSTEMS DO NOT OPERATE , Diagnostics for A/C System Malfunction. |
| 2 CHECK THE LIGHTING OF THE LED. Make sure that all switch LEDs on the control panel illuminate. | Do all LEDs blink eight times? | Go to step 3. | Replace the control panel. |
| 3 CHECK SENSOR MALFUNCTION. Set the air flow control dial and the fan speed control dial to AUTO. If the system has trouble for each sensor, the FRESH/RECIRC switch LED blinks or is turned off. If the system has no malfunctions, the FRESH/RECIRC switch LED is illuminated. | Does the FRESH/RECIRC switch LED illuminate? | Go to step 5. | Go to step 4 . |
| 4 CONFIRM MALFUNCTIONING SENSOR. Set the air flow control dial to AUTO. Turn the fan speed control dial to each mode position, and check each switch LED illumination according to sensor check table. Refer to SENSOR CHECK TABLE , OPERATION, Diagnostic Chart for Self-Diagnosis. | When turning the fan speed control dial to each mode position, does the FRESH/RECIRC switch LED go off? | Go to step 5. | Repair the defective sensor. Refer to DIAGNOSTIC PROCEDURE FOR SENSORS . |
| 5 CHECK AIR MIX DOOR AND MODE DOOR POSITION SIGNALS. Set the air flow control dial to FACE. Turn the fan speed control dial to AUTO. If there is a system malfunction in the air mix door signal or the mode door position signal, the FRESH/RECIRC switch LED goes off or blinks. If the system has no malfunctions, the FRESH/RECIRC switch LED is illuminated. | Does the FRESH/RECIRC switch LED illuminate? | Go to step 8. | Go to step 6 . |
| 6 CHECK AIR MIX DOOR DRIVE SIGNAL. Set the air flow control dial to FACE. Place the fan speed control dial in each position and then check each LED illumination conditions. Refer to DRIVE SIGNAL CHECK TABLE , OPERATION, Diagnostic Chart for Self-Diagnosis. | Do the LEDs illuminate in accordance with operation signal table? | Go to step 7. | Check the air mix door actuator circuit. Refer to AIR MIX DOOR ACTUATOR , Diagnostic Procedure for Actuators. |
| 7 CHECK MODE DOOR POSITION DRIVE SIGNAL. Press the A/C switch. Place the fan speed control dial in each position and then check each LED illumination conditions. Refer to DRIVE SIGNAL CHECK TABLE , OPERATION, Diagnostic Chart for Self-Diagnosis. | Do the LEDs illuminate in accordance with operation signal table? | Go to step 8. | Check the mode door actuator circuit. Refer to MODE DOOR ACTUATOR , Diagnostic Procedure for Actuators. |
| 8 CHECK OPERATION OF EACH ACTUATOR, BLOWER FAN AND COMPRESSOR CLUTCH. Set the air flow control dial to B/L. Turn the fan speed control dial from AUTO to 7th, and select operating modes. Check the operation of each mode according to operating mode table. Refer to OPERATING MODE TABLE , OPERATION, Diagnostic Chart for Self-Diagnosis. FRESH/RECIRC door Air flow control door Air mix door Blower fan A/C compressor | Does the operation of each mode match to operating mode table? | Turn the fan speed control dial to OFF or the ignition switch to OFF in order to complete self-diagnosis. | Repair the malfunctioning part in accordance with each diagnostic chart. |
DIAGNOSIS PROCEDURE
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 206
| Step | Check | Yes | No |
|---|---|---|---|
| 1 CHECK FUSE. Turn the ignition switch to OFF. Remove the fuse No. 7, No. 22 and No. 31 from fuse & relay box. Check the condition of fuse. | Is the fuse blown out? | Replace the fuse. | Go to step 2 . |
| 2 CHECK A/C CONTROL MODULE POWER CIRCUIT. Remove the A/C control panel. Disconnect the A/C control panel harness connector. Turn the ignition switch to ACC, and measure the voltage between A/C control panel harness connector terminal and chassis ground. Connector & terminal (i88) No. 15 (+) - Chassis ground (-) | Is the voltage 10 V or more? | Go to step 3. | Check for open or short circuit in the harness between A/C control panel and fuse. |
| 3 CHECK A/C CONTROL MODULE 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. 32 (+) - 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. 34 - Chassis ground | Is the resistance less than 10 ohms? | Go to step 5. | Repair the harness for ground line. |
| 5 CHECK POOR CONTACT. Check poor contact of auto A/C control module connector. | Is there poor contact of connector? | Repair the connector. | Replace the auto A/C control module. Refer to REMOVAL , Control Unit (Auto A/C Model). |
DIAGNOSIS PROCEDURE
- Blower motor does not rotate.
- Blower motor does not change speeds.
Scheme 207
| 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 OF BLOWER MOTOR RELAY. Turn the ignition switch to OFF. Remove the blower motor relay. Turn the ignition switch to ON. Use a tester to measure the voltage between the terminals. Connector & terminal (B386) 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. Connect the battery positive terminal to the blower motor relay terminal No. 2, and the negative terminal to No. 4. Using the tester, measure the resistance between terminals. Connector & terminal (Relay) No. 1 - No. 5 | Is the resistance less than 1 ohms? | Go to step 4. | Replace the blower motor relay. |
| 4 CHECK HARNESS. Remove the auto A/C control module. Measure the resistance between auto A/C control module and relay using a tester. Connector & terminal (B386) No. 4 - (i88) No. 9 | Is the resistance less than 1 ohms? | Go to step 5. | Repair or replace the harness. |
| 5 CHECK BLOWER MOTOR POWER SUPPLY. Install the blower motor relay and auto A/C control module. Turn the ignition switch to ON. Turn the blower fan switch to ON. Use a tester to measure the voltage between the blower motor and chassis ground. Connector & terminal (B87) No. 2 (+) - Chassis ground (-) | Is the voltage 10 V or more? | Go to step 6. | Repair or replace the harness between relay and the blower motor. |
| 6 CHECK BLOWER MOTOR. Turn the ignition switch to OFF. Disconnect the connector from blower motor. Connect the battery positive terminal to the blower motor connector terminal No. 2, and the negative terminal to No. 1. Make sure the blower motor runs. | Does the blower motor run? | Go to step 7. | Replace the blower motor. Refer to REMOVAL , Blower Motor. |
| 7 CHECK HARNESS. Disconnect the power transistor connector. Disconnect the auto A/C control module connector. Using the tester, measure the resistance between terminals of harness. Connector & terminal (B57) No. 1 - Chassis ground: (B57) No. 2 - (i88) No. 40: (B57) No. 3 - (B87) No. 1: (B57) No. 4 - (B87) No. 2: (B57) No. 4 - (B386) No. 5 | Is the resistance less than 1 ohms? | Go to step 8. | Repair or replace the harness. |
| 8 CHECK FAN CONTROL SIGNAL. Connect the disconnected connectors. Turn the ignition switch to ON. Change the fan speed control dial from 1st to 7th. Measure the voltage between the power transistor and chassis ground using a tester. Connector & terminal (B57) No. 2 (+) - Chassis ground (-) | Is the voltage approx. 10 V at 1st and approx. 1 V at 7th? | Replace the power transistor. Refer to REMOVAL , Power Transistor (Auto A/C Model). | Go to step 9 . |
| 9 CHECK POOR CONTACT. Check poor contact of auto A/C control module connector. | Is there poor contact of connector? | Repair the connector. | Replace the auto A/C control module. Refer to REMOVAL , Control Unit (Auto A/C Model). |
DIAGNOSIS PROCEDURE
- The blower rotates even though the blower switch is not turned on.
- The blower motor continues to rotate at high speed. (Not adjustable.)
- Compartment temperature does not change. (Cold air does not come out.)
- A/C system does not respond. (Response is extremely slow)
Scheme 208
| 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 SIGNAL 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 (-): (i88) No. 11(+) - 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. 2 - (F27) No. 17: (B10) No. 2 - (i88) No. 11 | Is the resistance less than 1 ohms? | Check the pressure switch. Refer to INSPECTION , Pressure Switch (Triple Pressure Switch). | 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. Refer to INSPECTION , Relay and Fuse. | Is the A/C relay OK? | Go to step 7. | Replace the A/C relay. |
| 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 A/C 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 (i88) No. 36 (+) - Chassis ground (-) | Is the voltage 5.5 V or more? | Go to step 8. | Replace the auto A/C control module. Refer to REMOVAL , Control Unit (Auto A/C Model). |
| 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 (i88) No. 36 - (B136) No. 24 | Is the resistance less than 1 ohms? | Go to step 9. | Repair the harness. |
| 9 CHECK MAGNET CLUTCH ON SIGNAL. Stop the engine and turn the A/C 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 A/C 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. Refer to REMOVAL , Engine Control Module (ECM). Refer to REMOVAL , Engine Control Module (ECM). |
| 11 CHECK POWER SUPPLY FOR MAGNET CLUTCH. Stop the engine and turn the A/C switch to OFF. Disconnect the harness connector of magnet clutch. Start the engine and turn the A/C 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? | Inspect the compressor. Refer to INSPECTION , Compressor. | Check for open or short circuit in the harness between A/C relay and magnet clutch. |
DIAGNOSIS PROCEDURE
FRESH/RECIRC mode is not changed.
Scheme 209
| 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 (B163) No. 1 (+) - Chassis ground (-) | Is the voltage approx. 10 V or more? | 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 (i88) No. 8 - (B163) No. 6: (i88) No. 7 - (B163) No. 5: (i88) No. 6 - (B163) No. 4 | 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 (i88) No. 6 - 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 | Does the actuator move to the RECIRC side? | Replace the auto A/C control module. Refer to REMOVAL , Control Unit (Auto A/C Model). | Replace the intake door actuator. |
DIAGNOSIS PROCEDURE
Air flow outlet is not changed.
Scheme 210
| Step | Check | Yes | No |
|---|---|---|---|
| 1 CHECK POWER SUPPLY FOR MODE DOOR ACTUATOR. Turn the ignition switch to OFF. Disconnect the mode door actuator connector. Turn the ignition switch to ON. Measure the voltage between the mode door actuator connector terminal and chassis ground. Connector & terminal (B77) No. 3 (+) - Chassis ground (-) | Is the voltage approx. 10 V or more? | Go to step 2. | Check the DC power supply circuit. |
| 2 CHECK MODE DOOR ACTUATOR. Turn the ignition switch to OFF. Disconnect the mode door actuator connector. Measure the resistance between mode door actuator terminals using a tester. Connector & terminal (B77) No.3 - No.1: (B77) No.3 - No.2: (B77) No.3 - No.5: (B77) No.3 - No.6 | Is the resistance between 80 - 100ohms? | Go to step 3. | Replace the mode door actuator. |
| 3 CHECK HARNESS BETWEEN AUTO A/C CONTROL MODULE AND MODE DOOR ACTUATOR. 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 - (i88) No. 4: (B77) No. 2 - (i88) No. 3: (B77) No. 5 - (i88) No. 2: (B77) No. 6 - (i88) No. 1 | Is the resistance less than 1 ohms? | Go to step 4. | Repair the harness between auto A/C control module and mode door actuator. |
| 4 CHECK POOR CONTACT. Check poor contact of auto A/C control module and connector. | Is there poor contact of connector? | Repair the connector. | Replace the auto A/C control module. Refer to REMOVAL , Control Unit (Auto A/C Model). |
DIAGNOSIS PROCEDURE
Outlet air temperature does not change.
Scheme 211
| Step | Check | Yes | No |
|---|---|---|---|
| 1 CHECK POWER SUPPLY OF AIR MIX DOOR ACTUATOR. Turn the ignition switch to OFF. Disconnect the air mix door actuator connector. Turn the ignition switch to ON. Measure the voltage between the air mix door actuator connector terminal and chassis ground. Connector & terminal (B239) No. 3 (+) - Chassis ground (-) | Is the voltage approx. 10 V or more? | Go to step 2. | Check the DC power supply circuit. |
| 2 CHECK AIR MIX DOOR ACTUATOR. Turn the ignition switch to OFF. Measure the resistance between air mix actuator terminals using a tester. Connector & terminal (B239) No.3 - No.1: (B239) No.3 - No.2: (B239) No.3 - No.5: (B239) No.3 - No.6 | Is the resistance between 80 - 100ohms? | Go to step 3. | Replace the air mix door actuator. |
| 3 CHECK HARNESS BETWEEN AUTO A/C CONTROL MODULE AND AIR MIX DOOR ACTUATOR. 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 (B239) No. 1 - (i88) No. 28: (B239) No. 2 - (i88) No. 27: (B239) No. 5 - (i88) No. 26: (B239) No. 6 - (i88) No. 25 | Is the resistance less than 1 ohms? | Go to step 4. | Repair the harness between auto A/C control module and air mix door actuator. |
| 4 CHECK POOR CONTACT. Check poor contact of auto A/C control module and connector. | Is there poor contact of connector? | Repair the connector. | Replace the auto A/C control module. Refer to REMOVAL , Control Unit (Auto A/C Model). |
DIAGNOSIS PROCEDURE
- Fan speed is not switched when the fan speed control dial is in AUTO position.
- Failure related to the ambient sensor is indicated in self-diagnosis.
Scheme 212
| Step | Check | Yes | No |
|---|---|---|---|
| 1 CHECK AMBIENT SENSOR. Turn the ignition switch to OFF. Disconnect the connector from ambient sensor. Measure the resistance between terminals of ambient sensor. Terminals No.2 - No.1 | Is the resistance approximately 3 kohms at 25°C (77°F)? | Go to step 2. | Replace the ambient sensor. Refer to REMOVAL , Ambient Sensor (Auto A/C Model). |
| 2 CHECK INPUT SIGNAL FOR AMBIENT SENSOR. Turn the ignition to ON. Measure the voltage between connector (F78) terminals. Connector & terminal (F78) No. 2 (+) - No. 1 (-) | Is the voltage approx. 5 V? | Go to step 6. | Go to step 3 . |
| 3 CHECK COMBINATION METER OUTPUT SIGNAL. Turn the ignition switch to OFF. Draw out the combination meter. Disconnect the connector from ambient sensor. Turn the ignition switch to ON. Measure the voltage between the combination meter connector terminals. Connector & terminal (i10) No. 24 (+) - No. 23 (-) | Is the voltage approx. 5 V? | Go to step 4. | Replace the combination meter. Refer to REMOVAL , Combination Meter. |
| 4 CHECK HARNESS CONNECTOR BETWEEN COMBINATION METER AND AMBIENT SENSOR. Turn the ignition switch to OFF. Disconnect the connector from the combination meter. Measure the resistance of harness between combination meter and ambient sensor. Connector & terminal (F78) No. 2 - (i10) No. 24 | Is the resistance less than 1 ohms? | Go to step 5. | Repair the open circuit of the harness between the combination meter and ambient sensor. |
| 5 CHECK HARNESS CONNECTOR BETWEEN COMBINATION METER AND AMBIENT SENSOR. Measure the resistance of harness between combination meter and ambient sensor. Connector & terminal (F78) No. 1 - (i10) No. 23 | Is the resistance less than 1 ohms? | Replace the combination meter. Refer to REMOVAL , Combination Meter. | Repair the open circuit of the harness between the combination meter and ambient sensor. |
| 6 CHECK HARNESS CONNECTOR BETWEEN COMBINATION METER AND AUTO A/C CONTROL MODULE. Turn the ignition switch to OFF. Disconnect the connector from the combination meter. Disconnect the auto A/C control module connector. Measure the resistance of harness between the combination meter and auto A/C control module. Connector & terminal (i88) No. 19 - (i10) No. 26 | Is the resistance less than 1 ohms? | Go to step 7. | Repair the open circuit in the harness between the combination meter and auto A/C control module. Refer to LAN SYSTEM , CAUTION, General Description. |
| 7 CHECK HARNESS CONNECTOR BETWEEN COMBINATION METER AND AUTO A/C CONTROL MODULE. Measure the resistance of harness between the combination meter and auto A/C control module. Connector & terminal (i88) No. 20 - (i10) No. 27 | Is the resistance less than 1 ohms? | Go to step 8. | Repair the open circuit in the harness between the combination meter and auto A/C control module. Refer to LAN SYSTEM , CAUTION, General Description. |
| 8 CHECK POOR CONTACT. Check poor contact of auto A/C control module connector. | Is there poor contact of connector? | Repair the connector. | Replace the auto A/C control module. Refer to REMOVAL , Control Unit (Auto A/C Model). |
DIAGNOSIS PROCEDURE
- Blower fan speed, air flow outlet and FRESH/RECIRC do not change after turning the AUTO switch to ON.
- Failure related to the in-vehicle sensor is indicated in self-diagnosis.
Scheme 213
| 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 terminals of in-vehicle sensor. Terminals No. 1 - No. 2 | Is the resistance approximately 2.2 kohms at 25°C (77°F)? | Go to step 2. | Replace the in-vehicle sensor. Refer to REMOVAL , In-Vehicle Sensor (Auto A/C Model). |
| 2 CHECK INPUT SIGNAL FOR IN-VEHICLE SENSOR. Turn the ignition switch to ON. Measure the voltage between in-vehicle sensor harness connector terminals. 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 (i88) No. 17(+) - (i88) No. 14 (-) | 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 - (i88) No. 17 | 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 - (i88) No. 14 | 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 of connector? | Repair the connector. | Replace the auto A/C control module. Refer to REMOVAL , Control Unit (Auto A/C Model). |
DIAGNOSIS PROCEDURE
Scheme 214
| 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 terminals of the evaporator sensor. Terminals No. 1 - No. 2 | Is the resistance approx. 6.2 kohms at 0°C (32°F) and approx. 3.3 kohms at 15°C (59°F)? | Go to step 2. | Replace the evaporator sensor. Refer to REMOVAL , Evaporator. |
| 2 CHECK INPUT SIGNAL FOR EVAPORATOR SENSOR. Turn the ignition switch to ON. Measure the voltage between connector (B88) terminals. Connector & terminal (B88) 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 (i88) No. 18 (+) - (i88) No. 14 (-) | 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 - (i88) No. 18 | 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 - (i88) No. 14 | 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 of connector? | Repair the connector. | Replace the auto A/C control module. Refer to REMOVAL , Control Unit (Auto A/C Model). |
DIAGNOSIS PROCEDURE
- 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 215
| 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. 2 (+) - No. 1 (-) | 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 SUN-LOAD 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 - (i88) No. 16 | 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 SUN-LOAD SENSOR. Measure the resistance of the harness between the auto A/C control module and sunload sensor. Connector & terminal (i51) No. 1 - (i88) No. 14 | 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 (i88) No. 16 (+) - (i88) No. 14 (-) | Is the voltage between approx. 1.0-4.0 V? | Go to step 5. | Replace the sunload sensor. Refer to REMOVAL , Sunload Sensor (Auto A/C Model). |
| 5 CHECK POOR CONTACT. Check poor contact of auto A/C control module connector. | Is there poor contact of connector? | Repair the connector. | Replace the auto A/C control module. Refer to REMOVAL , Control Unit (Auto A/C Model). |
DIAGNOSIS PROCEDURE
| Symptom | Problem parts |
|---|---|
| A/C system fails to operate. | Fuse (F/B No. 7, 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 (F/B No. 7, 22, 31). Connector (Poor contact) |
| Illumination cannot dim. | Fuse (F/B No. 7, 22, 31). Connector (Poor contact) Auto A/C control module |
| Blower fan does not rotate or fan speed cannot be controlled. | Fuse (F/B No. 7, 22, 31). 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 |
| Vehicle interior temperature does not increase (hot 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 |
| Vehicle interior temperature does not decrease (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 |
PROBLEM SYMPTOM CHART