A/C Compressor Clutch Circuit Troubleshooting

NOTE:

It is normal for the A/C compressor to turn off under certain conditions, such as low idle, high engine coolant temperature, hard acceleration, or high/low refrigerant pressure.
Do not use this troubleshooting procedure if the fans are also inoperative with the A/C on. Refer to the SYMPTOM TROUBLESHOOTING INDEX .
Before doing any symptom troubleshooting, check for powertrain DTCs (see GENERAL TROUBLESHOOTING INFORMATION ). Also check for B-CAN codes (see HOW TO CHECK FOR DTCS WITH THE HONDA DIAGNOSTIC SYSTEM (HDS) ).

Check the No. 1 (30 A) fuse in the under-hood fuse/relay box, and the No. 14 (10 A) fuse in the under-dash fuse/relay box.
Are the fuses OK?

YES -Go to step 2.

NO -Replace the fuse(s), and recheck. If either fuse blows again, check for a short in the No. 1 (30 A) or No. 14 (10 A) fuse circuits.
Connect the HDS to the DLC.
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 -Go to step 6.

NO -Go to A/C PRESSURE SWITCH CIRCUIT TROUBLESHOOTING .

Using the HDS, confirm the following values in the PGM-FI Data List at idle.

PGM-FI DATA LIST REFERENCE

TP SENSOR	About 0.5 V
RPM	720 ± 50
ECT SENSOR 2	39-230°F (4-110°C)
A/C SWITCH	ON
A/C CLUTCH	ON

Are all the values within specifications?

YES -Go to step 7.

NO -Troubleshoot the value that is not within the specifications.

Turn the ignition switch to LOCK (0).
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?

YES -Go to step 9.

NO -Replace the A/C compressor clutch relay.
Measure the voltage between A/C compressor clutch relay 4P socket terminal No. 2 and body ground.

Fig 1: Measuring Voltage Between A/C Compressor Clutch Relay 4P Socket Terminal No. 2 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Go to step 10.

NO -Replace the under-hood fuse/relay box (see UNDER-HOOD FUSE/RELAY BOX ).
Connect A/C compressor clutch relay 4P socket terminals No. 1 and No. 2 with a jumper wire.

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

Does the A/C compressor clutch click?

YES -Go to step 11.

NO -Go to step 19.
Disconnect the jumper wire.
Turn the ignition switch to ON (II).
Measure the voltage between A/C compressor clutch relay 4P socket terminal No. 3 and body ground.

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

Is there battery voltage?

YES -Go to step 14.

NO -Repair an open in the BLK/YEL wire between the No. 14 (10 A) fuse in the under-dash fuse/relay box and the A/C compressor clutch relay socket.
Turn the ignition switch to LOCK (0).
Reinstall the A/C compressor clutch relay.
Make sure the A/C switch is OFF.
Turn the ignition switch to ON (II).
Measure the voltage between ECM/PCM connector E (31P) terminal No. 18 and body ground with the ECM/PCM connectors connected.

Fig 4: Measuring Voltage Between ECM/PCM Connector E (31P) Terminal No. 18 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Check for loose wires or poor connections at ECM/PCM connector E (31P). If the connections are good, substitute a known-good ECM/PCM, and recheck. If the symptom/indication goes away, replace the original ECM/PCM (see ECM/PCM REPLACEMENT ).

NO -Repair an open in the wire between the A/C compressor clutch relay and the ECM/PCM.
Disconnect the jumper wire.
Disconnect the A/C compressor clutch 1P connector.
Check for continuity between A/C compressor clutch relay 4P socket terminal No. 1 and A/C compressor clutch 1P connector terminal No. 1.

Fig 5: Checking Continuity Between A/C Compressor Clutch Relay 4P Socket Terminal No. 1 And A/C Compressor Clutch 1P Connector Terminal No. 1
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Check the A/C compressor clutch clearance, and the A/C compressor clutch field coil (see A/C COMPRESSOR CLUTCH CHECK ).

NO -Repair an open in the wire between the A/C compressor clutch relay socket and the A/C compressor clutch.