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 "W/Harness Inspection" procedure.

Ignition "OFF"

Disconnect ambient sensor and A/C control Module main harness connector.

Ignition "ON"

Measure voltage between Signal(F/B) terminal of ambient sensor harness connector and chassis ground.

Is the measured voltage within specification?

	▶ Go to "Check for open in harness" as follows.
	▶ Check for short to battery in harness. ▶ Repair as necessary and then go to "Verification of Vehicle Repair" procedure.

Ignition "OFF"

Disconnect ambient sensor and A/C control Module main harness connector.

Measure resistance between Signal(+) terminal of ambient sensor harness connector and Signal(+) terminal of A/C control Module harness connector.

Is the measured resistance within specification?

	▶ Go to "Ground circuit Inspection" procedure.
	▶ Check for open in harness. ▶ Repair as necessary and then go to "Verification of Vehicle Repair" procedure.

Ignition "OFF"

Disconnect ambient sensor and A/C control Module main harness connector.

Measure resistance between ground terminal of ambient sensor harness connector and ground terminal of A/C control Module harness connector.

Is the measured resistance within specification?

	▶ Go to " Component inspection" procedure .
	▶ Check for open in harness. ▶ Repair as necessary and then go to "Verification of Vehicle Repair" procedure.