Subaru Crosstrek Service Manual: Dtc b27a5 front internal antenna open

DTC detecting condition:

When open circuit occurs in the harness between keyless access CM and front interior antenna.

Trouble symptom:

Keyless access system does not function. (When the access key is in the front area of the passenger room)

CAUTION:

For replacement procedure of keyless access CM, refer to the “REGISTRATION MANUAL FOR IMMOBILIZER” provided as a separate volume.

1.CHECK LAN SYSTEM.

Inspect LAN system. Basic Diagnostic Procedure > PROCEDURE">

Is LAN system normal?

Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC B27A5 FRONT INTERNAL ANTENNA OPEN">Go to Step 2.

Perform the inspection according to the diagnosis for LAN system.

2.CHECK CONNECTOR.

1) Disconnect the keyless access CM connector.

2) Disconnect the front interior antenna connector.

Is the connector OK?

Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC B27A5 FRONT INTERNAL ANTENNA OPEN">Go to Step 3.

Repair or replace the connector.

3.CHECK HARNESS (OPEN CIRCUIT).

Using a tester, measure the resistance between the keyless access CM connector and front interior antenna connector, and between front interior antenna connector, keyless access CM connector and chassis ground.

Connector & terminal

(B574) No. 3 — (B579) No. 1:
(B574) No. 2 — (B579) No. 2:
(B572) No. 11 — Chassis ground:

Is the resistance less than 1 ??

Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC B27A5 FRONT INTERNAL ANTENNA OPEN">Go to Step 4.

Repair or replace the open circuit of harness.

4.CHECK HARNESS (GROUND SHORT CIRCUIT).

Using a tester, measure the resistance between the keyless access CM connector and chassis ground.

Connector & terminal

(B574) No. 3 — Chassis ground:
(B574) No. 2 — Chassis ground:

Is the resistance 10 k? or more?

Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC B27A5 FRONT INTERNAL ANTENNA OPEN">Go to Step 5.

Repair or replace the short circuit of the harness.

5.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)">

Is DTC B27A5 displayed?

Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC B27A5 FRONT INTERNAL ANTENNA OPEN">Go to Step 6.

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.

6.CHECK FRONT INTERIOR ANTENNA.

1) Replace the rear interior antenna with the front interior antenna. Keyless Access Indoor Antenna">

2) Using the Subaru Select Monitor, clear the memory. Clear Memory Mode">

3) Read the DTC using Subaru Select Monitor. Read Diagnostic Trouble Code (DTC)">

Is DTC B27A5 displayed?

Replace the keyless access CM. Keyless Access CM">

Malfunction occurred in the front interior antenna.

Dtc b27a2 passenger side external antenna open

Dtc b27a7 trunk/rear gate internal antenna open

Other materials:

Inspection
AIRBAG SYSTEM > Roll ConnectorINSPECTION1. VISUAL INSPECTIONCheck for the following, and replace the damaged parts with new parts.• Combination switch is cracked or deformed.• Roll connector is cracked or deformed.2. UNIT INSPECTION OF ROLL CONNECTORCAUTION:• Do not rotate the r ...

Read diagnostic trouble code (dtc) Operation
TIRE PRESSURE MONITORING SYSTEM (DIAGNOSTICS) > Read Diagnostic Trouble Code (DTC)OPERATION1. On «Start» display, select «Diagnosis».2. On «Vehicle selection» display, input the target vehicle information and select «Confirmed».3. On «Main Menu» display, select «Each System».4. On «S ...

Inspection
HVAC SYSTEM (HEATER, VENTILATOR AND A/C) > Relay and FuseINSPECTION1. CHECK FUSE1. Remove the fuse and inspect visually.2. If the fuse is blown out, replace the fuse.NOTE:If the fuse is blown again, check the system wiring harness.2. CHECK RELAY1. Check the resistance between relay terminals.&bul ...