DTC P0193: Fuel Rail Pressure Sensor Circuit High Bank 1: Notes

DTC detecting condition: 

Immediately at fault recognition

Trouble symptom: 

• Improper idling
• Poor driving performance

Wiring diagram: 

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

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK DTC  .
   1. Turn the ignition switch to ON.
   2. Using the Subaru Select Monitor or a general scan tool, read the DTC of [Engine]. Ref. to COMMON (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC P06B4 displayed? (Current code)

   Yes:  Check for DTC P06B4. Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC P06B4 SENSOR POWER SUPPLY "B" CIRCUIT LOW .

   No:  Go to  2.

2. CHECK DTC  .

   Using the Subaru Select Monitor or a general scan tool, read the DTC of [Engine]. Ref. to COMMON (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC P06B5 displayed? (Current code)

   Yes:  Check for DTC P06B5. Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)>DTC P06B5 SENSOR POWER SUPPLY "B" CIRCUIT HIGH .

   No:  Go to  3.

3. CHECK DATA MONITOR  .
   1. Start the engine.
   2. Using the Subaru Select Monitor, read the value in [Fuel Rail Pressure A].
   NOTE: For detailed operation procedures, refer to "COMMON (DIAGNOSTICS)". Ref. to COMMON (DIAGNOSTICS)>DATA MONITOR .

   Is the value of [Fuel Rail Pressure A] 30000 [kPa] (4350 psi) or more?

   Yes:  Go to  4.

   No:  Refer to "Check non-permanent occurrence malfunctions". Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>GENERAL DESCRIPTION>INSPECTION>CHECK NON-PERMANENT OCCURRENCE MALFUNCTIONS .

4. CHECK FUEL PRESSURE SENSOR POWER SUPPLY  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the connector from the fuel pressure sensor.
   3. Turn the ignition switch to ON.
   4. Measure the voltage between fuel pressure sensor connector and engine ground.

      Connector & terminal 

      (E68) No. 4 (+) - Engine ground (-):

   Is the voltage 4.5 - 5.5 V?

   Yes:  Go to  5.

   No:  Go to  7.

5. CHECK HARNESS BETWEEN ECM AND FUEL PRESSURE SENSOR CONNECTOR (OPEN)  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the connector from ECM.
   3. Measure the resistance of harness between ECM connector and fuel pressure sensor connector.

      Connector & terminal 

      (E51) No. 22 - (E68) No. 1:

      (E51) No. 33 - (E68) No. 2:

   Is the resistance less than 1 Ω?

   Yes:  Go to  6.

   No:  Repair the following item.

   • Open circuit in harness between ECM connector and fuel pressure sensor connector
   • Poor contact of J/C
6. CHECK HARNESS BETWEEN ECM AND FUEL PRESSURE SENSOR CONNECTOR (SHORT TO POWER SUPPLY)  .
   1. Connect all connectors.
   2. Turn the ignition switch to ON.
   3. Measure the voltage between ECM connector and engine ground.

      Connector & terminal 

      (E51) No. 22 (+) - Engine ground (-):

   Is the voltage 5 V or more?

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

   No:  Replace the fuel pressure sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DOTC)>FUEL PRESSURE SENSOR .

7. CHECK HARNESS BETWEEN ECM AND FUEL PRESSURE SENSOR CONNECTOR (OPEN)  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the connector from ECM.
   3. Measure the resistance of harness between ECM connector and fuel pressure sensor connector.

      Connector & terminal 

      (E51) No. 17 - (E68) No. 4:

   Is the resistance less than 1 Ω?

   Yes:  Go to  8.

   No:  Repair the following item.

   • Open circuit in harness between ECM connector and fuel pressure sensor connector
   • Poor contact of J/C
8. CHECK HARNESS BETWEEN ECM AND FUEL PRESSURE SENSOR CONNECTOR (SHORT TO GROUND)  .

   Measure the resistance between fuel pressure sensor connector and engine ground.

   Connector & terminal 

   (E68) No. 4 - Engine ground:

   Is the resistance 1 MΩ or more?

   Yes:  Replace the ECM. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DOTC)>ENGINE CONTROL MODULE (ECM) .

   No:  Repair the ground short circuit of harness between ECM connector and fuel pressure sensor connector.