1.CHECK CONNECTOR. 1) Check connecting condition of the A/C CM connector, seat heater relay connector, seat connector and coupling connector. 2) Read the DTC using Subaru Select Monitor. Read Diagnostic Trouble Code (DTC) | | Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC B14B1 SEAT HEATER THERMISTOR CIRCUIT OPEN (DRIVER) | 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 SEAT HEATER LH. 1) Disconnect the seat connector (R341). 2) Short No. 2 and No. 6 of seat connector (R341). 3) Read the DTC using Subaru Select Monitor. Read Diagnostic Trouble Code (DTC) | | Replace the seat heater module. Seat Heater System > REMOVAL | Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC B14B1 SEAT HEATER THERMISTOR CIRCUIT OPEN (DRIVER) |
3.CHECK HARNESS. 1) Restore the temporary shorted lines made in step 2. 2) Turn the ignition switch to ON. 3) Turn the seat heater switch LH to ON. 4) Using the tester, measure the voltage between terminals. Connector & terminal (R341) No. 2 (+) — (R341) No. 6 (−): | Is the voltage 4.5 — 5.0 V- | Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC B14B1 SEAT HEATER THERMISTOR CIRCUIT OPEN (DRIVER) | Repair or replace the open circuit of harness. |
4.CHECK HARNESS (OPEN CIRCUIT). 1) Disconnect the A/C CM connector. 2) Using a tester, check continuity between terminals. Connector & terminal (R341) No. 2 — (i80) No. 5: (R341) No. 6 — (i181) No. 18: | | Replace the A/C CM. Control Unit > REMOVAL | Repair or replace the open circuit of harness. |