DTC P023F: Fuel Pump Secondary Circuit/Open: Notes

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DTC detecting condition:

Immediately at fault recognition

Wiring diagram:

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

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 HIGH-PRESSURE FUEL PUMP .
Check the high-pressure fuel pump. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DOTC)>High Pressure Fuel Pump>INSPECTION .

Is the check result OK?

Yes : Go to 2.

No : Replace the high-pressure fuel pump. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DOTC)>HIGH PRESSURE FUEL PUMP .
CHECK HARNESS BETWEEN ECM AND HIGH-PRESSURE FUEL PUMP CONNECTOR (OPEN) .
1. Disconnect the connector from ECM.
2. Disconnect the connector from high-pressure fuel pump.
3. Measure the resistance of harness between ECM connector and high-pressure fuel pump connector.
  Connector & terminal
  
  (E159) No. 3 - (E160) No. 1:
  
  (E159) No. 4 - (E160) No. 2:
Is the resistance less than 1 Ω?

Yes : Go to 3.

No : Repair the open circuit in harness between ECM connector and high-pressure fuel pump connector.
CHECK HARNESS BETWEEN ECM AND HIGH-PRESSURE FUEL PUMP CONNECTOR (SHORT TO GROUND) .
Measure the resistance between high-pressure fuel pump connector and engine ground.

Connector & terminal

(E160) No. 1 - Engine ground:

(E160) No. 2 - Engine ground:

Is the resistance 1 MΩ or more?

Yes : Repair the poor contact of ECM connector.

No : Repair the short circuit to ground in harness between ECM connector and high-pressure fuel pump connector.