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Home >> Chevrolet >> 2021 >> Trailblazer RS, 4WD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 10 (Engine Controls And Fuel - 1.0L (L4B L4F L4G LIJ) Or 1.2L (L4H L4K LIF LIH) - Diagnostic Information And Procedures (2 Of 2)) >> Diagnostic Information and Procedures >> Engine Cranks But Does Not Run >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.
  1. Crank the engine for up to 15 s.
  2. Verify that DTC P0117, P0118, P0122, P0123, P0222, P0223, P0335, P0336, P0513, P0562, P0563, P0601, P0602, P0603, P0604, P0606, P062F, P0633, P0685, P0689, P0690, P1516, P1631, P1682, P16F3, P2101, P2119, or P2610 is not set.
    • Go to next step: If none of the DTCs are set 
  3. Ignition ON
  4. Verify the Theft Deterrent LED located in the driver information center illuminates momentarily.
    • Go to next step: If the LED 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.
    • Go to next step: If greater than 0 RPM 
  6. Ignition OFF.
    7. NOTE:

    It may be necessary to secure the EN-36012-A  Ignition System Diagnostic Harness to the spark plug boots with electrical tape.

  7. Install the EN-36012-A  Ignition System Diagnostic Harness to the spark plug boots.
  8. Connect the EL-26792  HEI Spark Tester between the boot of a spark plug wire and ground.
  9. Connect the remaining wires to the appropriate cylinders.
    10. NOTE:
    • Perform the spark test on at least 3 of the cylinders.
    • An erratic or weak spark is considered a no spark condition.
  10. Verify the spark tester sparks while cranking the engine.
    • Go to next step: If the spark tester sparks 
  11. Ignition OFF.
  12. Disconnect the harness connector at a Q17 Fuel Injector.
  13. Connect a test lamp between the control circuit and the ignition voltage circuit of the harness connector.
    14. NOTE:

    Perform the fuel injector test on at least 3 fuel injectors

  14. Verify the injector test lamp flashes while cranking the engine.
    • Go to next step: If the injector test lamp flashes 
  15. Ignition OFF.
  16. Install the CH-48027  Fuel Pressure Gauge.
  17. Ignition ON.
    18. 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 to less than 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.
    • Additional DTCs may set when using the fuel pump output control.
  18. Command the Fuel Pump Enable On several times with a scan tool.
  19. Verify the fuel pressure is between 345 - 650 kPa (50 - 94 PSI) while the fuel pump is running.
    • Go to next step: If within the specified range 
  20. Verify that the fuel pressure, after the fuel pump has turned OFF, decreases to less than 600 kPa (87 PSI) and does not decrease more than 34 kPa (5 PSI) in 1 minute.
    • Go to next step: If within the specified range 
  21. Verify none of the conditions listed below exist:
    • Collapsed air intake duct to the throttle body
    • Air filter and air intake system for restrictions and obstructions
    • Spark plugs for being gas or coolant fouled
    • A skewed manifold absolute pressure (MAP) sensor
    • A skewed engine coolant temperature (ECT) sensor
    • Test the exhaust system for restrictions. Refer to Restricted Exhaust .
    • Test the fuel for contamination. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
    • Engine mechanical condition, for example, worn timing belt or low compression - Refer to Symptoms - Engine Mechanical .
    • If a condition exists 

      Repair as necessary.

    • Go to next step: If no condition exists 
  22. All OK.
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