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 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 ).

Check the No. 20 (7.5 A) fuse in the under-hood fuse/relay box, and the No. 36 (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 the fuse(s) blow again, check for a short in the No. 20 (7.5 A) and No. 36 (10 A) fuse(s) circuit.
Connect the HDS to the DLC.
Start the engine.
Turn on the A/C.
Check the A/C CLUTCH in the PGM-FI Data List with the HDS.
Is the A/C CLUTCH on?

YES -Go to step 7.

NO -Go to step 6.

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

TP SENSOR	About 0.5 V
RPM	750-850
ECT SENSOR 2	176-212°F (80-100°C)
A/C SWITCH	ON
A/C PRESSURE SENSOR	196-3, 138 kPa (2.00-32.00 kgf/cm² ) [28.4-455.1 psi]

Are all the values within specifications?

YES -Go to step 7.

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

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 8.

NO -Replace the A/C compressor clutch relay.
Measure the voltage between A/C compressor clutch relay 4P socket terminal No. 1 and body ground.

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

Is there battery voltage?

YES -Go to step 9.

NO -Replace the under-hood fuse/relay box (see REMOVAL AND INSTALLATION ).
Connect A/C compressor clutch relay 4P socket terminals No. 1 and No. 2 with a jumper wire.

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

Does the A/C compressor clutch click?

YES -Go to step 10.

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 13.

NO -Repair an open in the wire between the No. 36 (10 A) fuse in the under-dash fuse/relay box and the A/C compressor clutch relay.
Turn the ignition switch to LOCK (0).
Reinstall the A/C compressor clutch relay.
Jump the SCS line with the HDS.
NOTE: This step must be done to protect the powertrain control module (PCM) from damage.
Disconnect PCM connector A (49P).
Connect PCM connector A (49P) terminal No. 13 to body ground with a jumper wire.

Fig 4: Identifying PCM Connector A (49P) Terminal No. 13 Connection With Body Ground Using Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Turn the ignition switch to ON (II).
Does the A/C compressor click?

YES -Check for loose wires or poor connections at PCM connector A (49P). If the connections are good, check the PCM grounds. If the grounds are good, substitute a known-good PCM (see SUBSTITUTING THE PCM ), and recheck. If the symptom/indication goes away, replace the original PCM (see PCM REPLACEMENT ).

NO -Repair an open in the wire between the A/C compressor clutch relay and the 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. 2 and A/C compressor clutch 1P connector terminal No. 1.

Fig 5: Checking Continuity Between A/C Compressor Clutch Relay 4P Socket Terminal No. 2 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 compressor clutch field coil (see A/C COMPRESSOR CLUTCH CHECK ). Repair as needed.

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