HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS) > Diagnostic Procedure for Actuators

AIR MIX DOOR ACTUATOR

TROUBLE SYMPTOM:

Outlet air temperature does not change.

WIRING DIAGRAM:

STEPCHECKYESNO

1.CHECK POWER SUPPLY OF AIR MIX DOOR ACTUATOR.

1) Turn the ignition switch to OFF.

2) Disconnect the air mix door actuator connector.

3) Turn the ignition switch to ON.

4) Measure the voltage between the air mix door actuator connector terminal and chassis ground.

Connector & terminal

(B239) No. 3 (+) — Chassis ground (−):

Is the voltage approx. 10 V or more?

Check the DC power supply circuit.

2.CHECK AIR MIX DOOR ACTUATOR.

1) Turn the ignition switch to OFF.

2) Measure the resistance between air mix door actuator terminals using a tester.

Connector & terminal

(B239) No. 3 — No. 1:

(B239) No. 3 — No. 2:

(B239) No. 3 — No. 5:

(B239) No. 3 — No. 6:

Is the resistance 80 — 100 Ω?

Replace the air mix door actuator.

3.CHECK HARNESS BETWEEN AUTO A/C CONTROL MODULE AND AIR MIX DOOR ACTUATOR.

1) Disconnect the auto A/C control module connector.

2) Measure the resistance between auto A/C control module and air mix door actuator connector.

Connector & terminal

(B239) No. 1 — (i88) No. 28:

(B239) No. 2 — (i88) No. 27:

(B239) No. 5 — (i88) No. 26:

(B239) No. 6 — (i88) No. 25:

Is the resistance less than 1 Ω?

Repair the harness between auto A/C control module and air mix door actuator.

4.CHECK FOR POOR CONTACT.

Check poor contact of auto A/C control module and connector.

Is there poor contact of connector?

Repair the connector.

Replace the auto A/C control module.