DTC P06B5: Sensor Power Supply "B" Circuit High: Notes

DTC detecting condition:

Immediately at fault recognition

Trouble symptom:

Improper idling

Wiring diagram:

Engine Electrical System Ref. to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM .

Courtesy of SUBARU OF AMERICA, INC.

Courtesy of SUBARU OF AMERICA, INC.

Courtesy of SUBARU OF AMERICA, INC.

Courtesy of SUBARU OF AMERICA, INC.

Courtesy of SUBARU OF AMERICA, INC.

Courtesy of SUBARU OF AMERICA, INC.

Courtesy of SUBARU OF AMERICA, INC.

Courtesy of SUBARU OF AMERICA, INC.

CAUTION: Use the check board when measuring the ECM terminal voltage and resistance. Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>GENERAL DESCRIPTION>PREPARATION TOOL>HOW TO USE CHECK BOARD .

NOTE: After the faulty parts are repaired or replaced, perform the final check in Basic Diagnostic Procedure. Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>BASIC DIAGNOSTIC PROCEDURE>PROCEDURE .

CHECK HARNESS BETWEEN ECM AND EACH SENSOR CONNECTOR (SHORT TO POWER SUPPLY) .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Measure the voltage between ECM connector and engine ground.
  Connector & terminal
  
  (B134) No. 50 - Engine ground:
Is the voltage 10 V or more?

Yes: Repair the short circuit to power in harness between the ECM connector and the following sensor connector.
- Mass air flow and intake air temperature sensor
- Leak check valve assembly
No: Go to 2.
CHECK HARNESS BETWEEN ECM AND EACH SENSOR CONNECTOR (SHORT TO POWER SUPPLY) .
Measure the voltage between ECM connector and engine ground.

Connector & terminal

(E158) No. 17 (+) - Engine ground (-):

Is the voltage 10 V or more?

Yes: Repair the short circuit to power in harness between the ECM connector and the following sensor connector.
- Fuel pressure sensor
- Electronic wastegate valve
- CPC pressure sensor
No: Go to 3.
CHECK HARNESS BETWEEN ECM AND ACCELERATOR PEDAL POSITION SENSOR CONNECTOR (SHORT TO POWER SUPPLY) .
Measure the voltage between ECM connector and engine ground.

Connector & terminal

(B134) No. 49 (+) - Engine ground (-):

Is the voltage 10 V or more?

Yes: Repair the short circuit to power supply in harness between ECM connector and accelerator pedal position sensor connector.

No: Go to 4.
CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL CONNECTOR (SHORT TO POWER SUPPLY) .
Measure the voltage between ECM connector and engine ground.

Connector & terminal

(E159) No. 22 (+) - Engine ground (-):

Is the voltage 10 V or more?

Yes: Repair the short circuit to power supply in the harness between ECM connector and electronic throttle control connector.

No: Go to 5.
CHECK HARNESS BETWEEN ECM AND CRANKSHAFT POSITION SENSOR CONNECTOR (SHORT TO POWER SUPPLY) .
Measure the voltage between ECM connector and engine ground.

Connector & terminal

(E159) No. 30 (+) - Engine ground (-):

Is the voltage 10 V or more?

Yes: Repair the short circuit to power in the harness between ECM connector and crankshaft position sensor connector.

No: Replace the ECM. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DOTC)>ENGINE CONTROL MODULE (ECM) .