A/C Signal Circuit Troubleshooting
- Do not use this troubleshooting procedure if any of the following items are operative: A/C condenser fan, radiator fan, A/C compressor. Refer to the Symptom Troubleshooting Index .
- Do not use this troubleshooting procedure if the A/C system pressure is abnormal (see A/C PRESSURE SENSOR ).
- Before doing symptom troubleshooting, check for powertrain DTCs (see GENERAL TROUBLESHOOTING INFORMATION ), and B-CAN DTCs (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ).
- Turn the ignition switch to LOCK (0).
- Connect the HDS to the DLC.
- Turn the ignition switch to ON (II).
- Check that the blower motor operates at all speeds.
Does the blower motor operate at all speeds?
YES -Go to step 5.
NO -Repair the problem in the blower motor circuit.
- Start the engine.
- Turn on the A/C.
- Check the A/C switch in the PGM-FI Data List with the HDS.
Is the A/C switch on?
YES -The A/C signal is OK at this time.
NO -Go to step 8.
- Check the A/C pressure sensor in the data list.
Is the A/C pressure sensor within specification?
YES -Go to step 9.
NO -Check for poor or loose connections at the A/C pressure sensor. If the connections are OK, replace the A/C pressure sensor (see A/C LINE REPLACEMENT ).
- Turn the ignition switch to LOCK (0).
- Disconnect the climate control unit 36P connector.
- Turn the ignition switch to ON (II)
- Measure the voltage between climate control unit 36P connector terminal No. 26 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES -Go to step 19.
NO -Go to step 13.
- Turn the ignition switch to LOCK (0).
- Disconnect the A/C compressor clutch 3P connector.
- Turn the ignition switch to ON (II).
- Measure the voltage between A/C compressor clutch 3P connector terminal No. 3 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES -Go to step 17.
NO -Repair an open in the wire between the A/C compressor and the under-dash fuse/relay box. If the wire is OK, substitute a known-good under-dash fuse/relay box, and recheck. If the symptom goes away, replace the original under-dash fuse/relay box.
- USA models (see REMOVAL AND INSTALLATION )
- Canada models (see CANADA MODEL )
- Test the A/C compressor thermal protector (see A/C COMPRESSOR CLUTCH CHECK ).
Is the A/C compressor thermal protector OK?
YES -Go to step 18.
NO -Replace the A/C compressor thermal protector (see A/C COMPRESSOR THERMAL PROTECTOR REPLACEMENT ).
- Check for continuity between climate control unit 36P connector terminal No. 26 and A/C compressor clutch 3P connector terminal No. 1.Fig 3: Checking Continuity Between Climate Control Unit 36P Connector Terminal No. 26 And A/C Compressor Clutch 3P Connector Terminal No. 1
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Check for loose wires or poor connections at the climate control unit 36P connector and at the A/C compressor clutch 3P connector.
NO -Repair an open in the wire between the climate control unit and A/C compressor.
- Turn the ignition switch to LOCK (0).
- Measure the evaporator temperature sensor resistance between climate control unit 36P connector terminals No. 1 and No. 23.Fig 4: Measuring Evaporator Temperature Sensor Resistance Between Climate Control Unit 36P Connector Terminals No. 1 And 23
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is the resistance less than 24 kΩ?
YES -Check for loose wires or poor connections at climate control unit 36P connector. If the connections are good, substitute a known-good climate control unit and recheck. If the symptom/indication goes away, replace the original climate control unit (see CLIMATE CONTROL UNIT REMOVAL/INSTALLATION ).
NO -Test the evaporator temperature sensor (see EVAPORATOR TEMPERATURE SENSOR TEST ).