LAN SYSTEM (DIAGNOSTICS) > Diagnostic Procedure with Diagnostic Trouble Code (DTC)

DTC B1500 KEYLESS UART COM. MALFUNCTION

DTC DETECTING CONDITION:

UART between keyless control unit and body integrated unit is open or shorted, the connector is not connected properly, or the terminal is crimped improperly.

TROUBLE SYMPTOM:

Door lock does not operate with keyless.

WIRING DIAGRAM:

STEPCHECKYESNO

1.CHECK DTC.

Read the DTC of body integrated unit using Subaru Select Monitor.

Is B1500 current malfunction?

2.CHECK DTC.

1) Turn the ignition switch to OFF.

2) Disconnect the connectors from body integrated unit and keyless entry control module.

3) Connect the disconnected connectors.

4) Read the DTC of body integrated unit using Subaru Select Monitor.

Is B1500 current malfunction?

3.CHECK HARNESS.

1) Turn the ignition switch to OFF.

2) Disconnect the connectors from body integrated unit and keyless entry control module.

3) Using the tester, measure the resistance between terminals of harness.

Connector & terminal

(i84) No. 24 — (R80) No. 3:

Is the resistance less than 10 Ω?

Repair the open circuit of harness or replace harness.

4.CHECK HARNESS.

Using the tester, measure the voltage between keyless entry control module and chassis ground.

Connector & terminal

(R80) No. 4 (+) — Chassis ground (−):

Is the voltage battery voltage?

Check the power supply circuit for keyless entry control module. Replace the body integrated unit.

5.CHECK OPERATION.

1) Install the keyless entry control module from other vehicle, which is working normally.

2) Register the keyless key which is working normally.

3) Operate the keyless key.

Is the door locking operate?

Replace the keyless entry control module.

Replace the body integrated unit.

6.CHECK CONNECTOR.

Disconnect the connectors from body integrated unit and keyless entry control module.

Is there poor contact in connector?

Repair the connector, or replace harness.

Temporary poor contact occurs.