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Home >> Alfa Romeo >> 2019 >> Giulia Base, AWD >> Repair and Diagnosis >> Engine Performance >> System >> 2.0L - DTCS P0480-00 To P0687-00 >> DTC Troubleshooting >> P051D-00-Crankcase Pressure Sensor Circuit High >> Diagnostic Test

Diagnostic Test

  1. CHECK FOR AN ACTIVE DTC 
    NOTE:

    If there are any 5-Volt Supply DTCs present, perform the diagnostics for those DTCs.

    1. With the scan tool, read Powertrain Control Module (PCM) DTCs and Freeze Frame Data and record on the repair order.
    2. Using the recorded Freeze Frame Data and the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
    3. With the scan tool, read PCM DTCs.

      Is the DTC active or pending?

      Yes 

      • Go To  2

      No 

  2. CHECK THE (K926) CRANKCASE PRESSURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE 
    1. Turn the ignition off.
    2. Disconnect the Crankcase Pressure Sensor harness connector.
    3. Turn the ignition on.
    4. Measure the voltage on the (K926) Crankcase Pressure Sensor Signal circuit at the Crankcase Pressure Sensor harness connector.

      Is the voltage above 5.2 volts?

      Yes 

      • Repair the (K926) Crankcase Pressure Sensor Signal circuit for a short to voltage.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  3
  3. CHECK THE (K926) CRANKCASE PRESSURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO THE (F853) 5-VOLT SUPPLY CIRCUIT 
    1. Turn the ignition off.
    2. Disconnect the PCM C2 harness connector.
    3. Check for continuity between the (K926) Crankcase Pressure Sensor Signal circuit and the (F853) 5-Volt Supply circuit at the Crankcase Pressure Sensor harness connector.

      Is there continuity between the (K926) Crankcase Pressure Sensor Signal circuit and the (F853) 5-Volt Supply circuit?

      Yes 

      • Repair the (K926) Crankcase Pressure Sensor Signal circuit for a short to the (F853) 5-Volt Supply circuit.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  4
  4. CHECK THE (K916) SENSOR GROUND CIRCUIT FOR AN OPEN OR HIGH RESISTANCE 
    1. Measure the resistance of the (K916) Sensor Ground circuit between the Crankcase Pressure Sensor harness connector and the PCM C2 harness connector.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Go To  5

      No 

      • Repair the (K916) Sensor Ground circuit for an open or high resistance.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  5. CHECK THE (K926) CRANKCASE PRESSURE SENSOR SIGNAL CIRCUIT FOR AN OPEN OR HIGH RESISTANCE 
    1. Measure the resistance of the (K926) Crankcase Pressure Sensor Signal circuit between the Crankcase Pressure Sensor harness connector and the PCM harness connector.

      Is the resistance below 3.0 Ohms?

      Yes 

      • Go To  6

      No 

      • Repair the (K926) Crankcase Pressure Sensor Signal circuit for an open or high resistance.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  6. CRANKCASE PRESSURE SENSOR 
    1. Reconnect the PCM C2 harness connector.
    2. Connect a jumper between the (K926) Crankcase Pressure Sensor Signal circuit and the (K916) Sensor Ground circuit at the Crankcase Pressure Sensor harness connector.
    3. Turn the ignition on.
    4. With the scan tool, read DTCs.
      NOTE:

      The scan tool should display the P051C-CRANKCASE PRESSURE SENSOR CIRCUIT LOW DTC as active or pending with the jumper in place.

      Does the DTC display as described above?

      Yes 

      • Replace the Crankcase Pressure Sensor in accordance with the Service Information.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  7
  7. CHECK RELATED PCM AND COMPONENT CONNECTIONS 
    1. Disconnect all PCM harness connectors.
    2. Disconnect all related in-line harness connections (if equipped).
    3. Disconnect the related component harness connectors.
    4. 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.

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