A/C Compressor Clutch Circuit Troubleshooting

NOTE:

Do not use this troubleshooting procedure if the fans are also inoperative with the A/C on. Refer to the SYMPTOM TROUBLESHOOTING INDEX .
Before performing symptom troubleshooting, check for powertrain DTCs (see GENERAL TROUBLESHOOTING INFORMATION ).

Check the No. 19 (20 A) fuse in the under-hood fuse/relay box and the No. 16 (7.5 A) fuse in the under-dash fuse/relay box.
Are the fuses OK?
1. YES - Go to step 2.
2. NO - Replace the fuse(s), and recheck.

Check the engine coolant temperature, the throttle position, and the idle speed (use the HDS PGM-FI data list if possible).

ECT SENSOR REFERENCE CHART

ECT sensor	187-212 °F (86-100 °C)
TP sensor	About 0.5 V
RPM	More than 900

Is the engine coolant temperature, throttle position, or idle speed OK?

YES - Go to step 3.
NO - Troubleshoot and repair the cause of the high engine coolant temperature, low idle, or excessively high throttle position sensor reading.

Remove the A/C compressor clutch relay from the under-hood fuse/relay box, and test it (see POWER RELAY TEST ).
Is the relay OK?
1. YES - Go to step 4.
2. NO - Replace the A/C compressor clutch relay.
Measure the voltage between the No. 1 terminal of the A/C compressor clutch relay 4P socket and body ground.

Fig 1: Measuring Voltage Between No. 1 Terminal Of A/C Compressor Clutch Relay 4P Socket And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?
1. YES - Go to step 5.
2. NO - Replace the under-hood fuse/relay box.
Connect the No. 1 and No. 2 terminals of the A/C compressor clutch relay 4P socket with a jumper wire.

Fig 2: Connecting Terminals No. 1 & 2 Of A/C Compressor Clutch Relay 4P Socket With Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Does the A/C compressor clutch click?
1. YES - Go to step 6.
2. NO - Go to step 15.
Disconnect the jumper wire.
Turn the ignition switch ON (II).
Measure the voltage between the No. 4 terminal of the A/C compressor clutch relay 4P socket and body ground.

Fig 3: Measuring Voltage Between No. 4 Terminal Of A/C Compressor Clutch Relay 4P Socket And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?
1. YES - Go to step 9.
2. NO - Repair open in the BLK/YEL wire between the No. 16 (7.5 A) fuse in the under-dash fuse/relay box and the A/C compressor clutch relay.
Turn the ignition switch OFF.
Reinstall the A/C compressor clutch relay.
Make sure the A/C switch is OFF.
Turn the ignition switch ON (II).
Using the backprobe set, measure the voltage between the No. 17 terminal of ECM connector A (32P) and body ground with the ECM connectors connected.

Fig 4: Measuring Voltage Between No. 17 Of ECM Connector A (32P) And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?
1. YES - Go to step 14.
2. NO - Repair open in the wire between the A/C compressor clutch relay and the ECM.
Using the backprobe set, measure the voltage between the No. 27 terminal of ECM connector A (32P) and body ground with the ECM connectors connected.

Fig 5: Measuring Voltage Between No. 27 Terminal Of ECM Connector A (32P) And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?
1. YES - Check for loose wires or poor connections at ECM connector A (32P). If the connections are good, substitute a known-good ECM, and recheck. If the symptom/indication goes away, replace the original ECM.
2. NO - Repair open in the wire between the ECM and the A/C pressure switch.
Disconnect the jumper wire.
Disconnect the A/C compressor clutch 1P connector.
Check for continuity between the No. 2 terminal of the A/C compressor clutch relay 4P socket and the No. 1 terminal of the A/C compressor clutch 1P connector.

Fig 6: Checking Continuity Between No. 2 Terminal Of A/C Compressor Clutch Relay 4P Socket And No. 1 Of A/C Compressor Clutch 1P Connector
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Check the A/C compressor clutch clearance, the thermal protector, and the A/C compressor clutch field coil (see A/C COMPRESSOR CLUTCH CHECK ).
2. NO - Repair open in the wire between the A/C compressor clutch relay and the A/C compressor clutch.