Many malfunctions in the electrical system are caused by poor connection. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.

Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration,or damage.

Has a problem been found?

	▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure.
	▶ Go to Next procedure.

IG KEY OFF.

Disconnect A/C Control Module connector.

Measure resistance between C-CAN High terminal of A/C Control Module connector and chassis ground.

Measure resistance between C-CAN Low terminal of A/C Control Module connector and chassis ground.

Ignition "OFF"

Connect A/C Control Module connector.

Ignition ON.

Measure voltage between C-CAN High terminal of A/C Control Module connector and chassis ground.

Measure voltage between C-CAN Low terminal of A/C Control Module connector and chassis ground.

Ignition OFF

Disonnect A/C Control Module, Engine ECM connector.

Measure the resistance between C-CAN-HIGH terminal of A/C Control Module harness connector and C-CAN-HIGH terminal of Engine ECM harness connector.

Measure the resistance between C-CAN-LOW terminal of A/C Control Module harness connector and C-CAN-LOW terminal of Engine ECM harness connector.

Is the measured value within specification ?

	▶ Check Control Module connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
	▶ Check open in communication line. And then, go to 'Verification of Vehicle Repair" procedure. ▶ Check short to battery in communication line. And then, go to 'Verification of Vehicle Repair" procedure. ▶ Check short to ground in communication line. And then, go to 'Verification of Vehicle Repair" procedure.