DTC P1193: Fuel Rail Pressure Sensor "B" Circuit High: Notes

1. - 

DTC detecting condition: 

Immediately at fault recognition

Trouble symptom: 

• Improper idling
• Poor driving performance

Wiring diagram: 

Engine Electrical System Ref. to WIRING SYSTEM (IMPREZA MODEL)>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM . Ref. to WIRING SYSTEM (CROSSTREK MODEL (EXCEPT FOR HEV))>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM .

• IMPREZA MODEL

Courtesy of SUBARU OF AMERICA, INC.

• CROSSTREK MODEL

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK DATA MONITOR  .
   1. Start the engine.
   2. Using the Subaru Select Monitor or a general scan tool, read the value of [Fuel Rail Pressure B].
   NOTE: For detailed operation procedures, refer to "Common (Diagnostics)". Ref. to COMMON (DIAG)>DATA MONITOR .

   Is the value of [Fuel Rail Pressure B] approx. 0 kPa (0 psi)?

   Yes:  Go to  2.

   No:  Refer to "Check non-permanent occurrence malfunctions". Ref. to ENGINE (DIAGNOSTICS) (H4DO 2.0 (EXCEPT FOR HEV))>GENERAL DESCRIPTION>INSPECTION>CHECK NON-PERMANENT OCCURRENCE MALFUNCTIONS .

2. 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 and terminal 

   (E162) No. 4 (+) - Chassis ground (-):

   Is the voltage 4.5 - 5.5 V?

   Yes:  Go to  3.

   No:  Go to  5.

3. 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 and terminal 

   (E158) No. 50 - (E162) No. 1:

   (E158) No. 58 - (E162) No. 2:

   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 ECM connector and fuel pressure sensor connector
   • Poor contact of J/C
4. 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 fuel pressure sensor connector and engine ground.

   Connector and terminal 

   (E158) No. 50 (+) - Engine ground (-):

   (E162) No. 1 (+) - 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) (H4DO (EXCEPT FOR HEV))>FUEL PRESSURE SENSOR .

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 and terminal 

   (E158) No. 41 - (E162) No. 4:

   Is the resistance less than 1 Ω?

   Yes:  Go to  6.

   No:  Repair the harness and connector.

   NOTE: In this case, 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 GROUND)  .

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

   Connector and terminal 

   (E158) No. 41 - Engine ground:

   (E162) No. 4 - Engine ground:

   Is the resistance 1 MΩ or more?

   Yes:  Replace the ECM. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO (EXCEPT FOR HEV))>ENGINE CONTROL MODULE (ECM) .

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