2003 Honda Civic 1.7L Eng LX Component AC PRESSURE SENSOR A/C Pressure Switch Circuit Troubleshooting NOTE: Do not use this troubleshooting procedure if any of the following items are operative; condenser fan, radiator fan, A/C compressor, or if the heater is inoperative. Refer to the symptom troubleshooting index. Before performing symptom troubleshooting, check for power train DTCs (see GENERAL TROUBLESHOOTING INFORMATION ). 1. Disconnect the A/C pressure switch 2P connector. 2. Turn the ignition switch ON (II). 3. Measure the voltage between the No. 2 terminal of the A/C pressure switch 2P connector and body ground.
Fig 1: Measuring Voltage Between No. 2 Terminal Of A/C Pressure Switch 2P Connector & Body Ground Is there battery voltage? 1. YES Go to step 4. 2. NO 1. '01 Model: Go to step 18. 2. '02 05 Models: Go to step 13. 4. Turn the ignition switch OFF. 5. Check for continuity between the No. 1 and No. 2 terminals of the A/C pressure switch.
Fig 2: Checking Continuity Between No. 1 & No. 2 Terminals Of A/C Pressure Switch Is there continuity? 1. YES Go to step 6. 2. NO Go to step 20. 6. Reconnect the A/C pressure switch 2P connector.
7. Disconnect heater control panel connector A (14P). 8. Turn the ignition switch ON (II). 9. Measure the voltage between the No. 4 terminal of heater control panel connector A (14P) and body ground. Fig 3: Measuring Voltage Between No. 4 Terminal Of Heater Control Panel Connector A (14P) & Body Ground Is there battery voltage? 1. YES Go to step 10. 2. NO Repair open in the wire between the heater control panel and the A/C pressure switch. 10. Turn the ignition switch OFF. 11. Disconnect heater control panel connector B (22P).
12. Measure the resistance between the No. 2 terminal of the heater control panel connector A (14P) and the No. 7 terminal of the heater control panel connector B (22P). Fig 4: Measuring Resistance Between No. 2 Terminal Of Heater Control Panel Connector A (14P) & No. 7 Terminal Of Heater Control Panel Connector B (22P) Is the resistance less than 24 k ohms? 1. YES Check for loose wires or poor connections at heater control panel connector A (14P) and B (22P) and at the A/C pressure switch 2P connector. If the connections are good, substitute a known good heater control panel, and recheck. If the symptom/ indication goes away, replace the original heater control panel. 2. NO Repair cause of high resistance in the evaporator temperature circuit. 13. Turn the ignition switch OFF.
14. Disconnect the compressor clutch 3P connector. 15. Check for continuity between the No. 2 terminal of the A/C pressure switch 2P connector and the No. 3 terminal of the compressor clutch 3P connector. Fig 5: Checking Continuity Between No. 2 Terminal Of A/C Pressure Switch 2P Connector & No. 3 Terminal Of Compressor Clutch 3P Connector Is there continuity? 1. YES Go to step 16. 2. NO Repair open in the wire between the A/C pressure switch and the compressor clutch. 16. Turn the ignition switch ON (II). 17. Measure the voltage between the No. 1 terminal of the compressor clutch 3P
connector and body ground. Fig 6: Measuring Voltage Between No. 1 Terminal Of Compressor Clutch 3P Connector & Body Ground Is there battery voltage? 1. YES Check the thermal protector (see step 4 on Compressor Clutch Check ). 2. NO Go to step 18. 18. Make sure the A/C switch is OFF. 19. Measure the voltage between the No. 9 terminal of under dash fuse/relay box connector F (12P) and body ground with the under dash fuse/relay box connectors connected.
Fig 7: Measuring Voltage Between No. 9 Terminal Under Dash Fuse/Relay Box Connector F (12P) & Body Ground Is there battery voltage? 1. YES 1. '01 Model: Repair open in the wire between the under dash fuse/relay box and the A/C pressure switch. 2. '02 05 Models: Repair open in the wire between the under dash fuse/relay box and the compressor clutch. 2. NO Refer to the multiplex control system (see COMPONENT LOCATION
INDEX ). 20. Check for proper A/C system pressure. Is there continuity? 1. YES Replace the A/C pressure switch. 2. NO Repair the A/C pressure problem. This estimate is to repair the A/C system in order to perform a final test on the vehicle