Circuit Inspection

Temperature Control Actuator and Its Circuit Inspection

Temperature Control Actuator Removal and Installation:Auto A/C
1) Remove temperature control actuator from HVAC unit referring to Removal and Installation Temperature Control Actuator Removal and Installation:Auto A/C.
2) Connect connector to temperature control actuator.
3) Set temperature selector to "MAX COOL" position with ignition switch turned ON.
4) Connect voltage meter between terminal "2" and body ground.
5) Turn temperature selector to "MAX HOT" position.
6) Measure output voltage variation while temperature control actuator is operated from "MAX COOL" position (B) to "MAX HOT" position (A) as following specification.

If measure voltage is out of specification or does not vary linearly as the shown in graph, check related wire circuit and HVAC control module. If wire circuits and HVAC control module are OK, go to next step.

Temperature control actuator output voltage
0.48 - 4.53 V (linear variation as following graph)









7) Set temperature selector of HVAC control module to "MAX HOT" position with ignition switch turned ON, and make sure if the position of actuator lever is "MAX HOT" position (A).
8) Turn ignition switch to OFF position, and then disconnect connector from temperature control actuator.
9) Measure resistance between terminal "1" and "2".

Temperature control actuator resistance between terminal "1" and "2" (MAX HOT position) (Reference value)
Approx. 0.45 kohms at 25 °C (77 °F)





10) Connect connector to temperature control actuator.
11) Set temperature selector of HVAC control module to "MAX COOL" position with ignition switch turned ON, and make sure if the position of actuator lever is "MAX COOL" position (B).
12) Turn ignition switch to OFF position, and then disconnect connector from temperature control actuator.
13) Measure resistance between terminal "1" and "2".

Temperature control actuator resistance between terminal "1" and "2" (MAX COOL position) (Reference value)
Approx. 4.3 kohms at 25 °C (77 °F)





If measure resistance is out of specification, replace the actuator with new one.