1.CHECK LAN SYSTEM. Inspect LAN system. Basic Diagnostic Procedure > PROCEDURE | | Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC B27A8 TRUNK/REAR GATE EXTERNAL ANTENNA OPEN | Perform the inspection according to the diagnosis for LAN system. |
2.CHECK CONNECTOR. 1) Disconnect the keyless access CM connector. 2) Disconnect the rear exterior antenna connector. | | Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC B27A8 TRUNK/REAR GATE EXTERNAL ANTENNA OPEN | Repair or replace the connector. |
3.CHECK POWER SUPPLY CIRCUIT. Using a tester, measure the voltage between the keyless access CM connector and chassis ground. Connector & terminal (i75) No. 24 (+) — Chassis ground (−): | Is the voltage 9.5 — 16 V- | Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC B27A8 TRUNK/REAR GATE EXTERNAL ANTENNA OPEN | Check the power supply circuit. |
4.CHECK HARNESS (OPEN CIRCUIT). Using a tester, measure the resistance between the keyless access CM connector and rear external antenna connector. Connector & terminal Sedan model (i241) No. 15 — (R299) No. 3: (i241) No. 16 — (R299) No. 1: OUTBACK model (i241) No. 15 — (D45) No. 3: (i241) No. 16 — (D45) No. 1: | Is the resistance less than 1 -- | Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC B27A8 TRUNK/REAR GATE EXTERNAL ANTENNA OPEN | Repair or replace the open circuit of harness. |
5.CHECK HARNESS (GROUND SHORT CIRCUIT). Using a tester, measure the resistance between the keyless access CM connector and chassis ground. Connector & terminal Sedan model (i241) No. 15 — Chassis ground: (i241) No. 16 — Chassis ground: OUTBACK model (i241) No. 15 — Chassis ground: (i241) No. 16 — Chassis ground: | Is the resistance 10 k- or more- | Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC B27A8 TRUNK/REAR GATE EXTERNAL ANTENNA OPEN | Repair or replace the short circuit of the harness. |
6.CHECK DTC. 1) Connect the keyless access CM connector. 2) Using the Subaru Select Monitor, clear the memory. Clear Memory Mode 3) Read DTC using the Subaru Select Monitor. Read Diagnostic Trouble Code (DTC) | | Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC B27A8 TRUNK/REAR GATE EXTERNAL ANTENNA 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. |
7.CHECK REAR EXTERIOR ANTENNA. 1) Replace the rear exterior antenna with the rear interior antenna. Keyless Access Indoor Antenna Keyless Access Outdoor Antenna 2) Using the Subaru Select Monitor, clear the memory. Clear Memory Mode 3) Read DTC using the Subaru Select Monitor. Read Diagnostic Trouble Code (DTC) | | Replace the keyless access CM. Keyless Access CM | Malfunction occurred in the rear external antenna. |