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Home >> Alfa Romeo >> 2019 >> Giulia Base, AWD >> Repair and Diagnosis >> Engine Performance >> System >> 2.0L - DTCS P0112-00 To P024B-00 >> DTC Troubleshooting >> P0191-00-Fuel Rail Pressure Sensor "A" Circuit Range/Performance >> Diagnostic Test

Diagnostic Test

  1. CHECK FOR AN ACTIVE DTC 
    1. With the scan tool, read DTCs and Freeze Frame Data and record on the repair order.
    2. With the scan tool, erase DTCs.
    3. Using the recorded Freeze Frame Data and the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
    4. With the scan tool, read DTCs.

      Did the DTC return?

      Yes 

      • Go To  2

      No 

  2. CHECK FOR HIGH RESISTANCE IN THE FUEL RAIL PRESSURE SENSOR (K179) SIGNAL 1 CIRCUIT 
    1. Turn the ignition off.
    2. Disconnect the Fuel Rail Pressure (FRP) Sensor harness connector.
    3. Disconnected PCM C2 harness connector.
    4. Measure the resistance of the Fuel Rail Pressure Sensor (K179) Signal 1 circuit between the FRP Sensor harness connector and the PCM C2 harness connector.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Go To  3

      No 

      • Repair the Fuel Rail Pressure Sensor (K179) Signal 1 circuit for high resistance.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  3. CHECK FOR HIGH RESISTANCE IN THE FUEL RAIL PRESSURE SENSOR (K162) SIGNAL 2 CIRCUIT 
    1. Measure the resistance of the Fuel Rail Pressure Sensor (K162) Signal 2 circuit between the FRP Sensor harness connector and the PCM C2 harness connector.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Go To  4

      No 

      • Repair the Fuel Rail Pressure Sensor (K162) Signal 2 circuit for high resistance.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  4. REPLACE THE FUEL RAIL PRESSURE SENSOR AND RETEST FOR DTC 
    1. Replace the Fuel Rail Pressure Sensor in accordance with the Service Information. Refer to SENSOR, FUEL RAIL PRESSURE, REMOVAL AND INSTALLATION .
    2. With the scan tool, erase DTCs.
    3. Using the recorded Freeze Frame Data and the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
    4. With the scan tool, read DTCs.

      Did the DTC return?

      Yes 

      • Go To  5

      No 

      • Replacing the Fuel Rail Pressure Sensor repaired the fault.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  5. CHECK RELATED PCM AND COMPONENT CONNECTIONS 
    1. Perform any Service Bulletins that apply.
    2. Disconnect all PCM harness connectors.
    3. Disconnect all related in-line harness connections (if equipped).
    4. Disconnect the related component harness connectors.
    5. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
      • Proper connector installation.
      • Damaged connector locks.
      • Corrosion.
      • Other signs of water intrusion.
      • Weather seal damage (if equipped).
      • Bent terminals.
      • Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
      • Terminals that have been pushed back into the connector cavity.
      • Check for spread terminals and verify proper terminal tension.

      Repair any conditions that are found.

    6. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
    7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
    8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
    9. With the scan tool, erase DTCs.
    10. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
    11. With the scan tool, read DTCs.

      Did the DTC return?

      Yes 

      No 

      • The wiring or poor connection problem has been repaired.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .