RETRIEVING DIAGNOSTIC TROUBLE CODES

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1 Page 1 of 13 SELF-DIAGNOSTICS A/C-heater control assembly monitors system circuits and stores a code in memory if a problem is detected. All codes are stored in memory except Code 2 Malfunction is current if Code 22 is displayed. To retrieve stored codes, see RETRIEVING DIAGNOSTIC TROUBLE CODES. Codes are displayed at A/C-heater control assembly temperature display. See Fig. 2. RETRIEVING DIAGNOSTIC TROUBLE CODES Indicator Check While pressing and holding AUTO and fresh/recirculated air switches simultaneously, turn ignition on. See Fig. 2. Indicators will flash on and off at one second intervals 4 times in succession. Press OFF button to cancel indicator check. After indicator check is complete, system will enter self-diagnostic mode. Stored trouble codes will appear in sequence on temperature display panel. See AUTOMATIC A/C-HEATER SYSTEM TROUBLE CODES table. Press front defrost switch to display codes one at a time. Press OFF button to exit self-diagnostics. AUTOMATIC A/C-HEATER SYSTEM TROUBLE CODES Code Number Condition/Affected Circuit 00 Normal 11 (1) In-Vehicle Temperature Sensor Circuit 12 (2) Ambient Temperature Sensor Circuit 13 Evaporator Temperature Sensor Circuit 14 Engine Coolant Temperature Sensor Circuit 21 (3) Solar Sensor Circuit 22 (4) Compressor Lock Sensor Circuit 23 Pressure Switch Circuit 31 Air Mix Damper Position Sensor Circuit 32 Air Inlet Damper Position Sensor Circuit 41 Air Mix Servomotor Circuit 42 Air Inlet Servomotor Circuit (1) If in-vehicle temperature is -7 F (-18.6 C) or less, Code 11 may set even though system is normal. (2) If outside air temperature is -64 F (-59 C) or less, Code 12 may set even though system is normal. (3) If testing is done in a dark area, Code 21 may set even though system is normal. Shine a light at solar sensor and recheck codes. (4) Malfunction is current. Code is not stored in memory. CLEARING CODES

2 Page 2 of 13 Remove ECU-B fuse from fuse block, located in engine compartment on left fender near battery, for 10 seconds or longer. After reinstalling fuse, ensure only normal code (Code 00) appears. ACTUATOR CHECK Perform INDICATOR CHECK under RETRIEVING DIAGNOSTIC TROUBLE CODES. When system enters self-diagnostic mode, press fresh/recirculated air switch. Every mode damper, motor and relay will operate at one-second intervals. Press front defrost switch to display codes one at a time and to step through checks one at a time. Check airflow and temperature by hand. Each code is associated with a system operating condition. See Fig. 1. Press OFF button to cancel actuator check mode. Fig. 3: Identifying Actuator Check Display Codes CODE 11: IN-VEHICLE TEMPERATURE SENSOR CIRCUIT terminals A17-4 (Green/Yellow wire) and A16-1 (White/Red wire) at A/C control assembly harness connector. See Fig. 4. Measure voltage while heating sensor. See IN-VEHICLE TEMPERATURE SENSOR CIRCUIT VOLTAGE SPECIFICATIONS table. IN-VEHICLE TEMPERATURE SENSOR CIRCUIT VOLTAGE SPECIFICATIONS

3 Page 3 of 13 Sensor Temperature F ( C) 77 (25) (40) 2-6 (1) As temperature increases, voltage should gradually decrease. 4. If voltage is not as specified, test in-vehicle temperature sensor. See IN-VEHICLE TEMPERATURE SENSOR under TESTING. Replace sensor if it is defective. If sensor is okay, go to next step. Inspect wiring harness and connectors between sensor and A/C control assembly. Repair harness and connectors as necessary. If wiring harness and connectors are okay, temporarily substitute known-good A/C control assembly and retest system. Fig. 4: Identifying A/C Control Assembly Harness Connector Terminals (Viewed From Harness Side Of Connector) CODE 12: AMBIENT TEMPERATURE SENSOR CIRCUIT 4. terminals A17-3 (Yellow wire) and A16-1 (White/Red wire) at A/C control assembly harness connector. See Fig. 4. Measure voltage while heating outside (ambient) temperature sensor. See AMBIENT TEMPERATURE SENSOR CIRCUIT VOLTAGE SPECIFICATIONS table. If voltage is not as specified, test sensor. See AMBIENT TEMPERATURE SENSOR under TESTING. Replace sensor if it is defective. If sensor is okay, go to next step. Inspect wiring harness and connectors between sensor and A/C control assembly. Repair harness and connectors as necessary. If wiring harness and connectors are okay, temporarily substitute a known-good A/C control assembly and retest system.

4 Page 4 of 13 AMBIENT TEMPERATURE SENSOR CIRCUIT VOLTAGE SPECIFICATIONS Sensor Temperature F ( C) 77 (25) (40) (1) As temperature increases, voltage should gradually decrease. CODE 13: EVAPORATOR TEMPERATURE SENSOR CIRCUIT 4. terminals A17-6 (Blue/White wire) and A16-1 (White/Red wire) at A/C control assembly harness connector. See Fig. 4. Measure evaporator temperature sensor voltage at the temperatures specified. See EVAPORATOR TEMPERATURE SENSOR CIRCUIT VOLTAGE SPECIFICATIONS table. If voltage is not as specified, test evaporator temperature sensor. See EVAPORATOR TEMPERATURE SENSOR under TESTING. Replace sensor if it is defective. If sensor is okay, go to next step. Inspect wiring harness and connectors between sensor and A/C control assembly. Repair harness and connectors as necessary. If wiring harness and connectors are okay, temporarily substitute a known-good A/C control assembly. Retest system. EVAPORATOR TEMPERATURE SENSOR CIRCUIT VOLTAGE SPECIFICATIONS Sensor Temperature F ( C) 32 (0) (15) 4-8 (1) As temperature increases, voltage should gradually decrease. CODE 14: ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT terminals A17-14 (Violet wire) and A16-1 (White/Red wire) at A/C control assembly harness connector. See Fig. 4. Measure sensor voltage. See ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT VOLTAGE SPECIFICATIONS table. If voltage is not as specified, test engine coolant temperature sensor. See ENGINE COOLANT TEMPERATURE SENSOR under TESTING. Replace sensor if it is defective. If sensor is okay, go to next step. Inspect wiring harness and connectors between sensor and A/C control assembly. Repair as necessary. If wiring harness and connectors are okay, temporarily substitute known-good A/C control assembly. Retest system. ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT VOLTAGE SPECIFICATIONS

5 Page 5 of 13 Sensor Temperature F ( C) 32 (0) (40) (70) (1) As temperature increases, voltage should gradually decrease. CODE 21: SOLAR SENSOR CIRCUIT NOTE: If testing is done in a dark area, Code 21 may occur even though system is normal. Shine a light at solar sensor and recheck for Code 2 terminals A16-11 (Blue wire) and A17-5 (White wire) at A/C control assembly harness connector. See Fig. 4. Measure sensor voltage. See SOLAR SENSOR CIRCUIT VOLTAGE SPECIFICATIONS table. If voltage is not as specified, test solar sensor. See SOLAR SENSOR under TESTING. Replace sensor if it is defective. If sensor is okay, go to next step. Inspect wiring harness and connectors between sensor and A/C control assembly. Repair as necessary. If wiring harness and connectors are okay, temporarily substitute known-good A/C control assembly and retest system. SOLAR SENSOR CIRCUIT VOLTAGE SPECIFICATIONS Condition Sensor Subjected To Bright Light Less Than 4.0 Sensor Covered By Cloth (1) As light intensity decreases, voltage should increase. CODE 22: COMPRESSOR LOCK SENSOR CIRCUIT Ensure drive belt is installed properly, and belt tension is correct. Start engine. Turn blower and A/C on. Observe compressor. If compressor locks during operation, repair compressor. If compressor does not lock during operation, test compressor lock sensor. See COMPRESSOR LOCK SENSOR under TESTING. Replace compressor lock sensor if it is defective. If sensor is okay, inspect wiring harness and connectors between sensor and A/C control assembly. Repair as necessary. If wiring harness and connectors are okay, temporarily substitute known-good A/C control assembly. Retest system. CODE 23: PRESSURE SWITCH CIRCUIT ASSEMBLY under REMOVAL & INSTALLATION. Install manifold gauge set. Turn ignition

6 Page 6 of 13 x on. Backprobe between terminal A17-9 (Blue/Black wire) at A/C control assembly harness connector and ground. See Fig. 4. Start engine. Turn A/C on. Pressure switch operation should be as specified. See Fig. 5. If pressure switch operation is not as specified, go to next step. If pressure switch operation is as specified, circuit is okay. Unplug pressure switch connector, located on receiver/drier. Test for continuity between switch terminals No. 1 (Blue/Black wire) and No. 4 (Green wire) at refrigerant pressures specified. See Fig. 6. Replace pressure switch if operation is not as specified. If switch is okay, inspect wiring harness and connectors between switch and A/C control assembly. If wiring harness and connectors are okay, substitute known-good A/C control assembly. Retest system. Fig. 5: Measuring Pressure Switch Voltage

7 Page 7 of 13 Fig. 6: Testing Pressure Switch Continuity CODE 31 OR 41: AIR MIX DAMPER POSITION SENSOR/SERVOMOTOR CIRCUIT NOTE: For Code 41, see CODE 41: AIR MIX SERVOMOTOR CIRCUIT for additional trouble shooting procedures. 4. terminals A17-8 (Black/Yellow wire) and A16-1 (White/Red wire) at A/C control assembly harness connector. See Fig. 4. Measure sensor voltage while changing set temperature to activate air mix damper. See AIR MIX DAMPER POSITION SENSOR CIRCUIT VOLTAGE table. If voltage is not as specified, test air mix servomotor. See AIR MIX SERVOMOTOR under TESTING. Replace servomotor if it is defective. If servomotor is okay, go to next step. Inspect wiring harness and connectors between sensor and A/C control assembly. Repair as necessary. If wiring harness and connectors are okay, temporarily substitute known-good A/C control assembly. Retest system. AIR MIX DAMPER POSITION SENSOR CIRCUIT VOLTAGE Set Temperature Maximum Cool Maximum Hot (1) As set temperature increases, voltage should gradually decrease. CODE 32 OR 42: AIR INLET DAMPER POSITION SENSOR/SERVOMOTOR CIRCUIT NOTE: For Code 42, see CODE 42: AIR INLET SERVOMOTOR CIRCUIT for additional trouble shooting procedures. 4. terminals A17-7 (Blue/Yellow wire) and A16-1 (White/Red wire) at A/C control assembly harness connector. See Fig. 4. Measure sensor voltage while alternately pressing fresh air and recirculated air buttons to activate air inlet damper. See AIR INLET DAMPER POSITION CIRCUIT VOLTAGE SPECIFICATIONS table. If voltage is not as specified, test air inlet servomotor. See AIR INLET SERVOMOTOR under TESTING. Replace servomotor if it is defective. If servomotor is okay, go to next step. Inspect wiring harness and connectors between sensor and A/C control assembly. Repair as necessary. If wiring harness and connectors are okay, temporarily substitute known-good A/C control assembly. Retest system. AIR INLET DAMPER POSITION CIRCUIT VOLTAGE SPECIFICATIONS

8 Page 8 of 13 Switch Pressed Recirculated Air Fresh Air (1) As damper moves from recirculated air position toward fresh air position, voltage should gradually decrease. CODE 41: AIR MIX SERVOMOTOR CIRCUIT NOTE: See CODE 31 OR 41: AIR MIX DAMPER POSITION SENSOR/SERVOMOTOR CIRCUIT for additional trouble shooting procedures. Actuator Check Warm engine to normal operating temperature. Perform RETRIEVING DIAGNOSTIC TROUBLE CODES. After system enters self-diagnostic mode, perform ACTUATOR CHECK. Press DEF switch and check operation of air mix damper and blower condition. See AIR MIX DAMPER AIRFLOW table. Air mix damper operation should be as specified. If air mix damper operates as specified, circuit is okay. If air mix damper does not operate as specified, see AIR MIX SERVOMOTOR FUNCTIONAL CHECK. AIR MIX DAMPER AIRFLOW Code Air Mix Door Expected Result 0-3 Fully Closed Cool Air Comes Out 4-5 Half Open Blend (Cool/Hot) Air Comes Out 6-9 Fully Open Hot Air Comes Out Air Mix Servomotor Functional Check Remove air mix servomotor. See AIR MIX SERVOMOTOR under REMOVAL & INSTALLATION. Unplug air mix servomotor connector. Apply battery voltage to servomotor connector terminal No. 1 (Pink wire). See Fig. 7. Connect terminal No. 2 (Green/Red wire) to ground. Air mix servomotor lever should move to cool position. Transpose battery and ground leads. Servomotor lever should move to hot position. Replace air mix servomotor if it does not function as specified. If operation is as specified, inspect wiring harness and connectors between servomotor and A/C control assembly. Repair as necessary. If wiring harness and connectors are okay, substitute known-good A/C control assembly and retest system.

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10 Page 10 of 13 Fig. 7: Testing Air Mix Servomotor CODE 42: AIR INLET SERVOMOTOR CIRCUIT NOTE: See CODE 32 OR 42: AIR INLET DAMPER POSITION SENSOR/SERVOMOTOR CIRCUIT for additional trouble shooting procedures. Actuator Check Remove glove box. Perform RETRIEVING DIAGNOSTIC TROUBLE CODES. After system enters self-diagnostic mode, perform ACTUATOR CHECK. Press DEF button to enter step mode and display codes. See AIR INLET DAMPER AIRFLOW table. Air inlet damper operation should be as specified. If air inlet damper functions as specified, circuit is okay. If air inlet damper does not function as specified, test air inlet servomotor. See AIR INLET SERVOMOTOR FUNCTIONAL CHECK. AIR INLET DAMPER AIRFLOW Code Door Position 0-2 Fresh Air 3 Fresh/Recirculated Air 4-9 Recirculated Air Air Inlet Servomotor Functional Check Remove air inlet servomotor. See AIR INLET SERVOMOTOR under REMOVAL & INSTALLATION. Unplug air inlet servomotor connector. Connect battery voltage to air inlet servomotor connector terminal No. 7 (Red wire). See Fig. 8. Connect terminal No. 6 (Blue/Yellow wire) to ground. Air inlet servomotor lever should move to recirculated air (REC) position. Transpose battery and ground leads. Air inlet servomotor lever should move to fresh air (FRS) position. Replace air inlet servomotor if it does not operate as specified. If servomotor operates correctly, inspect wiring harness and connectors between servomotor and A/C control assembly. Repair as necessary. If wiring harness and connectors are okay, substitute known-good A/C control assembly and retest system.

11 Page 11 of 13 Fig. 8: Testing Air Inlet Servomotor

12 Page 12 of 13 Fig. 2: Identifying A/C-Heater System Controls

13 Page 13 of 13 Fig. 1: Identifying Automatic A/C-Heater System Components 2008 Mitchell Repair Information Co., LLC.

A/C-HEATER SYSTEM - AUTOMATIC

A/C-HEATER SYSTEM - AUTOMATIC 1996 Subaru SVX 1995-96 AUTOMATIC A/C-HEATER SYSTEMS Subaru SVX * PLEASE READ THIS FIRST * WARNING: To avoid injury from accidental air bag deployment, read and carefully