PROCEDURE
| Step | Check | Yes | No |
|---|---|---|---|
| 1 START INSPECTIONS. Perform the pre-inspection. INSPECTION, General Description .> Perform the self-diagnosis. OPERATION, Diagnostic Chart for Self-diagnosis .> | Does the self-diagnosis operate? | Go to step 2. | A/C OR SELF-DIAGNOSIS SYSTEMS DO NOT OPERATE, Diagnostics for A/C System Malfunction .> |
| 2 IDENTIFY MALFUNCTION PART. Identify the malfunction part with self-diagnosis. | Can the malfunction part be confirmed? | Repair the malfunctioning part in accordance with each diagnostic chart. | Go to step 3. |
| 3 CHECK COMPARTMENT TEMPERATURE. Turn on the A/C switch. Turn the temperature control dial at maximum cool position. Check the compartment temperature change. | Does the compartment temperature change? | Go to step 4. | COMPARTMENT TEMPERATURE DOES NOT CHANGE, OR A/C SYSTEM DOES NOT RESPOND PROMPTLY, Diagnostics for A/C System Malfunction .> |
| 4 CHECK A/C SYSTEM RESPONSE. Change the temperature setting, and check the response of A/C system. | Does the A/C system respond quickly? | A/C system is normal. | COMPARTMENT TEMPERATURE DOES NOT CHANGE, OR A/C SYSTEM DOES NOT RESPOND PROMPTLY, Diagnostics for A/C System Malfunction .> |
BASIC DIAGNOSTIC PROCEDURE
CAUTION
- Never connect the battery in reverse polarity. Doing so may immediately damage the auto A/C control module.
- Do not disconnect the battery terminals while the engine is running. A large counter electromotive force will be generated in the generator, and this voltage may damage electronic parts such as auto A/C control module etc.
- Before disconnecting the connectors of sensors and the auto A/C control module, be sure to turn off the ignition switch. Auto A/C control module may be damaged.
- Every A/C-related part is a precision part. Do not drop them.
- Airbag system wiring harness is routed near the A/C control panel and junction box. CAUTION: Do not use electrical test equipment on wiring harness and connector circuits of the air-bag system. Be careful not to damage the airbag system wiring harness when servicing the A/C control panel and junction box.
BATTERY
- Measure the battery voltage and specific gravity of electrolyte. Standard voltage: 12 V Specific gravity: 1.260 or more
- Check the condition of the fuses for A/C system power supply and other fuses.
- Check the condition of harness and harness connector connections.
Scheme 52
- Turn the ignition switch to ON, and press the A/C switch.
- Turn the temperature control dial to maximum hot position.
- Turn the air flow control dial to "DEF" position.
- Turn the fan dial to MAX.
- Put a strip of paper close to the front side of in-vehicle sensor suction port (A) located in the driver's side console side panel, and check that air is being sucked into the port by seeing the paper moving towards the port. NOTE: Be careful not to let the paper get sucked into the port.
- If the paper does not move at all, remove the driver's side console side panel REMOVAL , Center Console .> and check for improper connection of the aspirator hose, in-vehicle sensor and heater unit, and repair them if necessary.
A/C LINE
Check the connection for A/C line (A) and lower side high-pressure pipe.
Scheme 53
CONTROL LINKAGE
- Check the state of mode door linkage.
- Check the state of air mix door linkage.
- Check the state of RESH/RECIRC door linkage.
CONTROL SWITCHES
Start the engine and warm-up completely.
- Inspection using switches INSPECTION REFERENCE CHART No. Point to check Switch operation Judgment standard 1 OFF switch Press the OFF switch. Setting temperature display goes out. Blower fan: OFF Inlet opening: FRESH Compressor: OFF 2 AUTO switch, driver's side temperature control dial and passenger's side temperature control dial Press the AUTO switch. Turn the temperature control dial to the left fully, and set to 18°C(65°F) (maximum cool position). AUTO display illuminates. Outlet air temperature: COOL Blower fan: HI(AUTO) Outlet opening: FACE Inlet opening: AUTO Compressor: AUTO 3) Turn the temperature control dial to the right slowly, and change the setting from 18°C (65° F) (maximum cool position) to 32°C (85°F). Outlet air temperature: COOL --> HOT Blower fan: AUTO Outlet opening: FACE --> B/L --> FOOT Inlet opening: AUTO Compressor: AUTO 4) Turn the temperature control dial to the right fully, and set to 32°C (85°F) (maximum hot position). Outlet air temperature: HOT Blower fan: HI (AUTO) Outlet opening: FOOT Inlet opening: FRESH (AUTO) Compressor: AUTO 3 Defroster switch Press the defroster switch. Defroster switch indicator illuminates. Outlet air temperature: AUTO Blower fan: AUTO Outlet opening: DEF Inlet opening: FRESH Compressor: ON 4 FRESH/RECIRC switch Press the FRESH/RECIRC switch. Inlet opening switches RECIRC --> FRESH or FRESH --> RECIRC each time pressing the switch. 5 MODE switch Press the MODE switch. Outlet opening switches FACE --> B/L --> FOOT --> F/D each time pressing the switch. 6 FAN switch Press the FAN switch (+). Inlet opening switches LO --> M1 --> M2 --> M3 --> M4 --> HI each time pressing the switch.
- Compressor operation inspection INSPECTION REFERENCE CHART No. Point to check Switch operation Judgment standard 1 Compressor Turn the A/C switch to ON. Set the FAN switch between LO and HI. Compressor: ON
- Inspection of illumination control INSPECTION REFERENCE CHART No. Point to check Switch operation Judgment standard 1 Illumination Turn the lighting switch to ON. Illumination comes on.
Scheme 54
Scheme 55
Scheme 56
Scheme 57
Scheme 58
| Terminal No. | Remarks | Measuring condition | Standard |
|---|---|---|---|
| A1 | Battery power supply | Ignition switch: OFF | Battery voltage |
| A2 | ACC power supply | Ignition switch: ACC | Battery voltage |
| A3 | Mode door actuator position signal | Mode door: FACE position | 4V |
| Mode door: DEF position | 1 V | ||
| A4 | Passenger's side air mix door actuator position signal | Air mix door: Maximum cool position | 4V |
| Air mix door: Maximum hot position | 1 V | ||
| A5 | In-vehicle sensor | Ignition switch: ON | 5 V or less |
| A6 | Sunload sensor | Ignition switch: ON, With Sunload (No sunload: 0 V) | 3V |
| A8 | Sensor power supply | Ignition switch: ON | 5V |
| A9 | Ignition power supply | Ignition switch: ON | Battery voltage |
| A10 | A/C cut signal | Ignition switch: ON | Battery voltage |
| When pressure SW is operating | 0V | ||
| A12 | Driver's side air mix door actuator position signal | Air mix door: Maximum cool position | 4V |
| Air mix door: Maximum hot position | 1 V | ||
| A13 | Evaporator sensor | Ignition switch: ON | 5 V or less |
| A14, A16 | Ground | Continuity to chassis ground | 0 ohms |
| A15 | Sensor ground | Continuity to chassis ground | 0 ohms |
| B1, B11 | Ambient sensor, engine coolant temperature sensor | (1) | |
| B2 | Blower motor control | Ignition switch : ON, Blower switch : ON | 0.45 V |
| B3 | Blower motor control | Ignition switch : ON, Blower switch : ON | 9.05 V |
| B4 | RAM monitor | (1) | |
| B5 | RAM monitor | (1) | |
| B6 | A/C ON signal | A/C: ON (A/C OFF: 0 V) | 7 - 14V |
| B7 | Mode door actuator power supply | When switching mode door from DEF --> FACE | Battery voltage |
| B17 | When switching mode door from FACE --> DEF | Battery voltage | |
| B8 | Passenger's side air mix door actuator power supply | When switching air mix door from HOT --> COOL | Battery voltage |
| B18 | When switching air mix door from COOL --> HOT | Battery voltage | |
| B9 | Driver's side air mix door actuator power supply | When switching air mix door from HOT --> COOL | Battery voltage |
| B19 | When switching air mix door from COOL --> HOT | Battery voltage | |
| B10 | Intake door actuator | FRESH (RECIRC: Battery voltage) | 0V |
| B20 | RECIRC (FRESH: Battery voltage) | 0V | |
| B13 | Blower fan ON signal | When blower fan is rotating (Not rotating: Battery voltage) | 0V |
| B14 | RAM monitor | (1) | |
| B15, B16 | Control panel | (1) | |
| (1) Unable to measure the voltage for digital signal. | |||
| (1) | Unable to measure the voltage for digital signal. |
AUTO A/C CONTROL MODULE CONNECTOR TERMINALS SPECIFICATION CHART
AIR CONDITIONER AUTO A/C MODEL
AIR CONDITIONING , WIRING DIAGRAM, Air Conditioning System .>
Scheme 59
Note. For A/C system self-diagnosis, there is one that checks the control panel, and the other that checks the whole control system (sensor, actuator, blower motor, etc.). Perform the self-diagnosis for control panel first, and then perform the self-diagnosis for control system.
SENSOR CHECK TABLE
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.
| Display screen (Malfunction at present) (1) | Sensor | Trouble contents |
|---|---|---|
| 21/AUTO Blink | In-vehicle sensor | Open |
| 21/AUTO Blink | Short | |
| 22/AUTO Blink | Ambient sensor | Sensor trouble or communication failure |
| 23/AUTO Blink | Evaporator sensor | Open |
| 23/AUTO Blink | Short | |
| 24/AUTO Blink | Engine coolant temperature sensor | Sensor trouble or communication failure |
| 25 Blink | Sunload sensor | Open (2) |
| 25/AUTO Blink | Short | |
| 26/AUTO Blink | Driver's side air mix door actuator potentiometer | COOL |
| 27/AUTO Blink | HOT | |
| 26/AUTO Blink | Passenger's side air mix door actuator potentiometer | COOL |
| 27/AUTO Blink | HOT | |
| 28/AUTO Blink | Mode door actuator potentiometer | FACE |
| 29/AUTO Blink | DEF | |
| 20 Blink | When all conditions are normal | |
| (1) AUTO display does not blink when past malfunction occurred. Past malfunction means that abnormal signals were continuously input for a certain time in the past. (2) Present malfunction only is displayed for sunload sensor open circuit. | ||
| (1) | AUTO display does not blink when past malfunction occurred. Past malfunction means that abnormal signals were continuously input for a certain time in the past. |
| (2) | Present malfunction only is displayed for sunload sensor open circuit. |
SENSOR CHECK CHART
OPERATING MODE TABLE
| Display screen | FRESH/RECIRC door | Mode door | Air mix door (1) | Blower fan | A/C compressor (Magnet clutch) |
|---|---|---|---|---|---|
| 31 | FRESH | FACE | Maximum cool | LO | OFF |
| 32 | RECIRC | FACE | Maximum cool | LO | ON |
| 33 | RECIRC | FACE | Maximum cool | M1 | ON |
| 34 | FRESH | B/L | 50% | M1 | ON |
| 35 | FRESH | FOOT | 50% | M1 | ON |
| 36 | FRESH | FOOT | Maximum hot | M3 | ON |
| 37 | FRESH | F/D | Maximum hot | M3 | ON |
| 38 | FRESH | DEF | Maximum hot | HI | ON |
| (1) Same opening angle for both driver's and passenger's side | |||||
| (1) | Same opening angle for both driver's and passenger's side |
OPERATING MODE CHART
A/C LOCK SENSOR
H6 model
Scheme 60
| Step | Check | Yes | No |
|---|---|---|---|
| 1 CHECK A/C LOCK SENSOR SIGNAL. Turn the ignition switch to OFF. Connect the Subaru Select Monitor to the data link connector. Start the engine and turn the A/C switch to ON. Read the data of A/C lock signal using Subaru Select Monitor. NOTE: Subaru Select Monitor For detailed operation procedure, refer to "READ CURRENT DATA FOR ENGINE". READ CURRENT DATA FOR ENGINE (NORMAL MODE) , OPERATION, Subaru Select Monitor .> | Is the A/C lock signal switch ON? | Go to step 4. | Go to step 2. |
| 2 CHECK A/C LOCK SENSOR SIGNAL. Start the engine and turn the A/C switch to ON. Measure the voltage between auto A/C control module harness connector and chassis ground. Connector & terminal (B283) No. 6 (+) - Chassis ground (-) | Is the voltage 7 - 14 V? | Replace the auto A/C control module. | Go to step 3. |
| 3 CHECK ECM. Measure the voltage between ECM and chassis ground. Connector & terminal (B136) No. 24 (+) - Chassis ground (-) | Is the voltage 7 - 14 V? | Repair the harness between the ECM and the auto A/C control module connector. | Replace the ECM. |
| 4 CHECK A/C LOCK SENSOR. Turn the ignition switch to OFF. Disconnect the connector from ECM. Measure the resistance between ECM connector and chassis ground. Connector & terminal (B135) No. 14 - Chassis ground | Is the resistance between 240 - 290 ohms? | Replace the ECM. | Go to step 5. |
| 5 CHECK A/C LOCK SENSOR. Turn the ignition switch to OFF. Disconnect the main fuse box harness connector. Measure the resistance between main fuse box terminal. Connector & terminal (F37) No. 16 - No. 18 | Is the resistance between 240 - 290 ohms? | Go to step 7. | Go to step 6. |
| 6 CHECK A/C LOCK SENSOR. Turn the ignition switch to OFF. Disconnect the A/C lock sensor connector. Measure the resistance between A/C lock sensor terminals. Connector & terminal (F115)No. 1 - No.2 | Is the resistance between 240 - 290 ohms? | Repair or Replace the harness between A/C lock sensor and main fuse box. | Replace the A/C compressor assembly. (A/C lock switch malfunction) |
| 7 CHECK MAIN FUSE BOX. Turn the ignition switch to OFF. Disconnect the connector and then measure the resistance between main fuse box terminal. Connector & terminal (F37)No. 16 - (F143)No. 12: (F37)No. 18 - (F143) No. 14 | Is the resistance less than 10 ohms? | Repair or Replace the harness between A/C lock sensor and main fuse box. | Replace the main fuse box. |
| NOTE |
|---|
| Subaru Select Monitor For detailed operation procedure, refer to "READ CURRENT DATA FOR ENGINE". READ CURRENT DATA FOR ENGINE (NORMAL MODE) , OPERATION, Subaru Select Monitor .> |
DIAGNOSTIC PROCEDURE