DTC 18


id070200803100

DTC 18

Air mix actuator (potentiometer) system inspection

POSSIBLE CAUSE
•  Air mix actuator malfunction
•  Short to ground in wiring harness between A/C amplifier connector terminals 2D and 2N
•  Open circuit in wiring harness between A/C amplifier connector terminals 2P and 2N
•  Connector or terminal malfunction
•  Open circuit in wiring harness between A/C amplifier connector terminals 2D and 2P

Diagnostic Procedure

STEP

INSPECTION

ACTION

1
INSPECT AIR MIX ACTUATOR
•  Inspect the air mix actuator.
•  Is it normal?
Yes
Go to the next step.
No
Replace the air mix actuator.
2
INSPECT AIR MIX ACTUATOR (POTENTIOMETER) CIRCUIT FOR SHORT TO GROUND
•  Disconnect the airflow mode actuator connector.
•  Is the resistance between terminals 2D and 2N of the A/C amplifier connector (16-pin) 698 ohms or more?
Yes
Go to the next step.
No
Repair the wiring harness. (Short circuit)
3
INSPECT AIR MIX ACTUATOR (POTENTIOMETER) CIRCUIT FOR OPEN CIRCUIT
•  Disconnect the A/C amplifier connector (16-pin).
•  Is the resistance between terminals 2P and 2N of the A/C amplifier connector (16-pin) 6.0 kilohms or less?
Yes
Go to the next step.
No
Repair the wiring harness. (Open circuit)
4
INSPECT AIR MIX ACTUATOR (POTENTIOMETER) CIRCUIT FOR OPEN CIRCUIT
•  Is the resistance between terminals 2D and 2P of the A/C amplifier connector (16-pin) 5.2 kilohms or less?
Yes
Inspect the connection at the A/C amplifier connector (16-pin).
No
Repair the wiring harness. (Open circuit)