LEMON Manuals: Even more car manuals for everyone
Home >> Buick >> 2015 >> Regal GS, AWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 17 (Engine Controls And Fuel - 2.4L - DTC P0628 To DTC P2635 And Diagnostic Information And Procedures) >> Diagnostic Information and Procedures >> Engine Cranks But Does Not Run (LEA) >> Circuit/System Verification

Circuit/System Verification

WARNING: This page is about a different variant/trim than selected.
NOTE:

This diagnostic assumes the following:

  • The battery is completely charged.
  • The engine cranking speed is acceptable.
  • There is adequate fuel in the fuel tank.
  1. Crank the engine for up to 15s.
  2. Verify that DTC P0121, P0122, P0123, P0201, P0202, P0203, P0204, P0222, P0223, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, P0277, P0335, P0336, P0513, P0601, P0602, P0603, P0604, P0606, P0627-P0629, P062B, P062F, P0630, P0633, P069E, P1248, P1249, P124A, P124B, P1516, P1631, P1649, P16A0, P16A1, P16A2, P16F3, P2101, P2119, P2135, P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157, P2176, P262B, or U0109 is not set.
    • If none of the DTCs are set 
  3. Ignition ON
  4. Verify the security indicator on the instrument cluster illuminates momentarily.
    • If the security indicator does not stay ON and is not flashing 
  5. Verify the scan tool Engine Speed parameter displays greater than 0 RPM while cranking the engine.
    • If greater than 0 RPM 
    6. NOTE:

    A mass airflow sensor circuit condition may cause an Engine Cranks But Does Not Run condition without setting a DTC.

  6. Verify the scan tool Mass Airflow Sensor parameter displays greater than 0Hz while cranking the engine.
    • If greater than 0Hz 
  7. Ignition OFF, disconnect a T8 ignition coil from one of the cylinders. Refer to Ignition Coil Replacement .
  8. Connect the J 26792  HEI Spark Tester between the spark plug boot of the T8 ignition coil and ground.
  9. Verify the T8 ignition coil harness connector is connected.
    10. NOTE:

    Perform the spark test on at least 3 of the 4 cylinders.

  10. Verify the spark tester sparks while cranking the engine.
    • If the spark tester sparks 
  11. Ignition OFF, connect any T8 ignition coils that were disconnected. Refer to Ignition Coil Replacement .
  12. Install the CH48027  Digital Pressure Gauge. Refer to Fuel Pressure Gauge Installation and Removal .
  13. Ignition ON.
    14. NOTE:
    • If the engine is too hot, high fuel pressure readings may result due to hot soak fuel boiling. Allow the engine coolant temperature to cool down to below 60°C (150°F), before attempting to verify fuel pressure.
    • The Fuel Pump Enable may need to be commanded On a few times in order to obtain the highest possible fuel pressure.
  14. Command the Fuel Pump Enable On several times with a scan tool.
  15. Verify that the fuel pressure is between 345-650 kPa (50-94 psi) with the fuel pump running.
    • If within the specified range 
  16. Verify that the fuel pressure, after the fuel pump has turned OFF, decreases to less than 600 kPa (87 psi) and does not decrease greater than 34 kPa (5 psi) in 1 minute.
    • If within the specified range 
  17. Ignition OFF, disconnect the harness connector of a fuel injector.
  18. Connect a test lamp between the control circuit and the ignition voltage circuit of the harness connector.
    19. NOTE:

    Perform the fuel injector test on at least 3 fuel injectors

  19. Verify the test lamp flashes while cranking the engine.
    • If the test lamp flashes 
  20. Verify the conditions listed below do not exist:
scientia non olet · About LEMON Manuals