DTC P0191: Inspection

High Pressure Fuel Pump Cam Inspection 

Test Procedure 

• Procedure
  • Check for damage or wear on the high pressure fuel pump cam of the rear intake camshaft .

• Normal Conditions
  • There is no damage, and the rear intake camshaft wear is within the specified value.

Results 

• If it is abnormal, there is a problem with the rear intake camshaft.

  NOTE:  If there is the problem, check for damage, deformation, or wear on the roller of lifter attached with the high pressure fuel pump.

High Pressure Fuel Pump Inspection 

NOTE:  Since there is no direct method to test the inspection item, troubleshooting is performed using a known-good component.

Test Procedure 

• Install a known-good high pressure fuel pump and attempt to reproduce the failure.

Results 

• If the failure is reproduced, there is a problem with other related components.
• If the symptom/DTC goes away, the high pressure fuel pump must be faulty.

Fuel Rail Pressure Sensor Inspection (1) 

Test Procedure 

• Preparation
  • Fuel tank unit connector (4P): disconnected

• Procedure
  • Start the engine, and let it idle until it stalls.
  • After the engine stalls, crank the engine for several times.
  • Confirm the HDS [Fuel Pressure Converted From PF Sensor].

• Normal Conditions
  • The HDS [Fuel Pressure Converted From PF Sensor] value is less than 1,000 kPa  .

    NOTE:  It is normal if the value of several hundred kPa is indicated.

Results 

• If it is abnormal, there is a problem with the fuel rail.

Fuel Rail Pressure Sensor Inspection (2) 

Test Procedure 

• If the other inspection item(s) indicated a normal condition, then it is determined that the remaining fuel rail is the cause.

Results 

• There is a problem with the fuel rail.