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 B14B2 SEAT HEATER THERMISTOR CIRCUIT SHORT-CIRCUIT (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. 2) 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 B14B2 SEAT HEATER THERMISTOR CIRCUIT SHORT-CIRCUIT (DRIVER) |
3.CHECK HARNESS. 1) Turn the ignition switch to ON. 2) Turn the seat heater switch LH to ON. 3) 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 B14B2 SEAT HEATER THERMISTOR CIRCUIT SHORT-CIRCUIT (DRIVER) | Repair or replace the open circuit of harness. |
4.CHECK HARNESS (SHORTED BETWEEN LINES AND SHORTED TO GROUND). 1) Disconnect the A/C CM connector. 2) Using a tester, check continuity between terminals. Connector & terminal (R341) No. 2 — (R341) No. 6: (R341) No. 2 — Chassis ground: | | Repair or replace the short circuit of the harness. | Replace the A/C CM. Control Unit > REMOVAL |