Subaru Legacy BN/BS (2015-2019) Service Manual: Dtc b1438 mode door actuator circuit open

Subaru Legacy BN/BS (2015-2019) Service Manual / Hvac system (diagnostics) / Diagnostic procedure with diagnostic trouble code (dtc) / Dtc b1438 mode door actuator circuit open

DTC DETECTING CONDITION:

Mode door actuator potentiometer circuit is open.

TROUBLE SYMPTOM:

Vent does not change.

WIRING DIAGRAM:

Air conditioning system Air Conditioning System > WIRING DIAGRAM

STEP	CHECK	YES	NO
1.CHECK CONNECTOR. 1) Check connecting condition of the A/C CM connector and mode door actuator connector. 2) Read the DTC using Subaru Select Monitor. Read Diagnostic Trouble Code (DTC)	Is B1438 displayed-	Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC B1438 MODE DOOR ACTUATOR CIRCUIT OPEN	Even if DTC is displayed, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again. NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.
2.CHECK ACTUATOR. 1) Disconnect the mode door actuator. 2) Short No. 2 and No. 3 of (i176) connector. 3) Read the DTC using Subaru Select Monitor. Read Diagnostic Trouble Code (DTC)	Is B1439 displayed-	Replace the mode door actuator. Mode Door Actuator > REMOVAL	Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC B1438 MODE DOOR ACTUATOR CIRCUIT OPEN
3.CHECK HARNESS. 1) Restore the temporary shorted lines made in step 2. 2) Turn the ignition switch to ON. 3) Using the tester, measure the voltage between terminals. Connector & terminal (i176) No. 1 (+) — No. 2 (−):	Is the voltage 4.5 — 5.0 V-	Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC B1438 MODE DOOR ACTUATOR CIRCUIT OPEN	Repair the open circuit of harness.
4.CHECK HARNESS (OPEN CIRCUIT). Using a tester, check continuity between terminals. Connector & terminal (i176) No. 1 — (i181) No. 18: (i176) No. 2 — (i80) No. 6: (i176) No. 3 — (i80) No. 12:	Is there continuity-	Replace the A/C CM. Control Unit > REMOVAL	Repair or replace the open circuit of harness.

Dtc b1439 mode door actuator circuit short-circuit

DTC DETECTING CONDITION:Mode door actuator potentiometer circuit is shorted.TROUBLE SYMPTOM:Vent does not change.WIRING DIAGRAM:Air conditioning system Air Conditioning System > WIRING DIAGRAMSTEPCHE ...

Dtc b1437 air mix door actuator circuit short-circuit (passenger)

DTC DETECTING CONDITION:Air mix door actuator potentiometer circuit is shorted.TROUBLE SYMPTOM:Temperature of the passenger’s side cannot be adjusted for model with left/right independent air co ...

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