Subaru Legacy BN/BS (2015-2019) Service Manual: Dtc b1012 battery backup power supply

Subaru Legacy BN/BS (2015-2019) Service Manual / Body control system (diagnostics) / Diagnostic procedure with diagnostic trouble code (dtc) / Dtc b1012 battery backup power supply

DTC DETECTING CONDITION:

Voltage failure caused by poor contact of battery power supply backup circuits

BAT (back-up) voltage was outside the range of 8.3 — 16.7 V, when the BAT (back-up) power supply was ON.

Time Needed for Diagnosis:

40 s or more

TROUBLE SYMPTOM:

Illuminations for the keyless entry, map light, luggage light, trunk light, room light, and ignition switch do not turn on.

NOTE:

When B1011 BATTERY CONTROL POWER SUPPLY is output at the same time, all the function of body integrated unit may not operate.

WIRING DIAGRAM:

Immobilizer system Immobilizer System > WIRING DIAGRAM

STEP	CHECK	YES	NO
1.CHECK DTC. Read the DTC of body integrated unit using Subaru Select Monitor. Read Diagnostic Trouble Code (DTC)	Is DTC B1012 displayed- (Current malfunction)	Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC B1012 BATTERY BACKUP POWER SUPPLY	Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC B1012 BATTERY BACKUP POWER SUPPLY
2.CHECK DTC. 1) Turn the ignition switch to OFF. 2) Disconnect and then connect the body integrated unit connector. 3) Wait approx. 2 minutes. 4) Turn the ignition switch to ON. 5) Read the DTC of body integrated unit using Subaru Select Monitor. Read Diagnostic Trouble Code (DTC)	Is DTC B1012 displayed- (Current malfunction)	Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC B1012 BATTERY BACKUP POWER SUPPLY	Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC B1012 BATTERY BACKUP POWER SUPPLY
3.CHECK FUSE. 1) Turn the ignition switch to OFF. 2) Check the fuse.	Is the fuse OK-	Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC B1012 BATTERY BACKUP POWER SUPPLY	Replace the defective fuse.
4.CHECK HARNESS. 1) Disconnect the body integrated unit connector. 2) Using the tester, measure the voltage between terminals. Connector & terminal (B281) No. 32 (+) — Chassis ground (−):	Is the voltage 8.5 — 16.5 V-	Replace the body integrated unit. Body Integrated Unit	Repair the harness between body integrated unit and fuse.
5.CHECK CONNECTOR. 1) Turn the ignition switch to OFF. 2) Disconnect the body integrated unit connector.	Is there poor contact of connector-	Repair or replace the poor contact of connector.	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.

Dtc b1013 ignition power

DTC DETECTING CONDITION:Voltage failure caused by poor contact of IGN power supply circuitsIGN voltage was outside the range of 8.3 — 16.7 V, when the IGN power supply was ON.Time Needed for Diagnos ...

Dtc b1011 battery control power supply

DTC DETECTING CONDITION:• Voltage failure caused by poor contact of battery power supply control circuit• Battery voltage of body integrated unit is not within the range of 8.3 — 16.7 V. ...

Other materials:

Inspection
1. Measure the resistance between connector terminals.Preparation tool:Circuit testerTerminal No.Inspection conditionsStandard2 — 3Switch OFF1 M- or moreSwitch ONLess than 1 -2. Apply battery voltage between the connector terminals to check the lighting condition of the light.Terminal No.Inspectio ...