DTC U1712: Lost Lin Communication With Battery "1" Monitor Module: Notes
DTC detecting condition:
Immediately at fault recognition
- After servicing or replacing faulty parts, perform Clear Memory Mode Ref. to ENGINE (DIAGNOSTICS) (H6DO)>CLEAR MEMORY MODE>OPERATION ., and inspection mode Ref. to ENGINE (DIAGNOSTICS) (H6DO)>INSPECTION MODE>PROCEDURE .
- Use the check board when measuring the ECM terminal voltage and resistance.
Wiring diagram:
Engine Electrical System Ref. to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM .
- CHECK DTC
.
Read the engine DTC using the Subaru Select Monitor or general scan tool. Ref. to ENGINE (DIAGNOSTICS) (H6DO)>READ DIAGNOSTIC TROUBLE CODE (DTC) .
Is DTC U1712 displayed? (Current malfunction)
Yes: Go to 2 .
No: The circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.
- CHECK ECM CONNECTOR
.
Check the connecting condition of ECM connector.
Is the ECM connector correctly connected?
Yes: Go to 3 .
No: Connect the ECM connector correctly.
- CHECK HARNESS BETWEEN BATTERY AND BATTERY SENSOR CONNECTOR
.
- Turn the ignition switch to OFF.
- Disconnect the ground terminal from battery sensor. Ref. to REPAIR CONTENTS>NOTE>BATTERY .
- Disconnect the connector from battery sensor.
- Disconnect the positive terminal of battery.
- Measure the resistance of the harness between battery positive cable terminal and battery sensor connector.
Connector & terminal
Positive cable terminal - (B78) No. 1:
Is the resistance less than 1 Ω?
Yes: Go to 4 .
No: Repair the harness and connector.
NOTE: In this case, repair the following item:- Open circuit in harness between battery positive cable terminal and battery sensor connector
- Poor contact of coupling connector
- CHECK HARNESS BETWEEN ECM AND BATTERY SENSOR CONNECTOR
.
- Disconnect the connector from ECM.
- Measure the resistance of harness between ECM connector and battery sensor connector.
Connector & terminal
(B134) No. 55 - (B78) No. 2:
Is the resistance less than 1 Ω?
Yes: Repair the poor contact of ECM connector or battery sensor connector.
No: Repair the harness and connector.
NOTE: In this case, repair the following item:- Open circuit in harness between ECM connector and battery sensor connector
- Poor contact of coupling connector