Engine "ON".
Connect AQS sensor.
Measure voltage value between terminal "2" and "3" of AQS sensor.
Specification : Refer the specifications in fig3)
Is the measured voltage within specifications in fig3)?
YES
Go to "Check A/C Control Unit" procedure.
NO
Substitute with a AQS sensor and check for proper operation. If the problem is corrected, replace AQS sensor and then go to "Verification of Vehicle Repair" procedure.
Engine : "ON"
Disconnect AQS sensor.
Measure voltage between terminal "2" of A/C Control Unit and chassis ground
Specification :Approx. 5V
Is the measured voltage within specifications?
YES
Check 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.
NO
Substitute with a known-good A/C Control Unit and check for proper operation.
If the problem is corrected, replace A/C Control Unit and then go to "Verification of Vehicle Repair" procedure.