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) | | 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) | | 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: | | Replace the A/C CM. Control Unit > REMOVAL | Repair or replace the open circuit of harness. |