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. Check the No. 9 (20 A) fuse in the under-hood fuse/relay box, and the No. 30 (7.5 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.■
1. Check the engine coolant temperature, throttle position, and idle speed (use the HDS PGM-FI data list if possible).
   ECT Sensor | 76−90 °C (80−194 °F)
   TPS | About 0.5 V
   RPM (min −1 ) | More than 650
Is the coolant temperature, throttle position, and 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. Is the relay OK?
YES | - | Go to Step 4 .
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. Is there battery voltage?
YES | - | Go to Step 5 .
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. Does the A/C compressor clutch click?
YES | - | Go to Step 6 .
NO | - | Go to Step 15 .
Disconnect the jumper wire. Turn the ignition switch ON (II). |

Measure the voltage between No. 4 terminal of the A/C compressor clutch relay 4P socket and body ground. Is there battery voltage?
YES | - | Go to Step 9 .
NO | - | Repair open in the wire between the No. 30 fuse in the under-dash fuse/relay box and the A/C compressor clutch relay.■
Jump the SCS line with the HDS. Turn the ignition switch OFF. Reinstall the A/C compressor clutch relay. Disconnect ECM connector No. 2 (58P). Turn the ignition switch ON (II). |

Measure the voltage between the No. 45 terminal of ECM connector No. 2 (58P) and body ground. Is there battery voltage?
YES | - | Check for loose wires or poor connections at ECM connector No. 2 (58P). If the connections are good, substitute a known-good ECM, and recheck. If the symptom/indication goes away, replace the original ECM. ■
NO | - | Repair open in the wire between the A/C compressor clutch relay and the ECM.■
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. Is there continuity?
YES | - | Check the A/C compressor clutch clearance, and the A/C compressor clutch field coil. Repair as needed.■
NO | - | Repair open in the wire between the A/C compressor clutch relay and the A/C compressor clutch.■