Idle Control System

A/C Signal Circuit Troubleshooting

11-419  

  1. Turn the ignition switch ON (II).
  1. Momentarily connect ECM/PCM connector terminals A24 and E18 with a jumper wire several times.

ECM/PCM CONNECTORS A (31P)

Wire side of female terminals

Is there a clicking noise from the A/C compressor clutch?

YES

- Go to step 3.

NO

- Go to step 6.


  1. Start the engine.
  2. Turn the blower switch ON.
  3. Turn the A/C switch ON.

Does the A/C operate?

YES

- The air conditioning signal is OK.

NO

- Substitute a known-good ECM/PCM and recheck (see page 11-313). If symptom/indication goes away, replace the original ECM/PCM.


  1. Momentarily connect the under-hood fuse/relay box 14P connector terminal No. 10 and body ground with a jumper wire several times.

UNDER-HOOD FUSE/RELAY BOX 14P CONNECTOR

Wire side of female terminals

Is there clicking noise from the A/C compressor clutch?

YES

- Repair open in the wire between the ECM/PCM (E18) and the A/C clutch relay.

NO

- Check the A/C system for other symptoms.