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Home >> Chevrolet >> 2015 >> Cruze LT, Automatic Trans >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Controls And Fuel - 1.4L (LUJ, LUV) - DTC P0300 To DTC P2635 And Diagnostic Information And Procedures >> Diagnostic Information and Procedures >> DTC P2261: Turbocharger Bypass Valve >> Circuit/System Testing

Circuit/System Testing

  1. Verify the conditions listed below do not exist:
    • Vacuum leaks
    • Vacuum line restrictions
    • Improper routing or connecting of the vacuum hoses on the Q40 Turbocharger Bypass Solenoid Valve, the bypass valve and the bypass valve vacuum reservoir
    • If a condition exists 

      Repair or replace the component as necessary.

    • If none of the conditions exist 
  2. Disconnect the Q40 Turbocharger Bypass Solenoid Valve vacuum supply hose at the intake manifold.
  3. Connect the GE 23738-A  to the manifold.
  4. Engine Idling, verify the vacuum gauge displays between 45-67 kPa (13-20 inches Hg) of vacuum.
    NOTE: Allow engine idle to stabilize before continuing.
    • If not within the specified range 

      Repair the vacuum source.

    • If within the specified range 
  5. Ignition OFF, disconnect the vacuum hose at the turbocharger vacuum reservoir.
    NOTE: The vacuum reservoir (tank) is integral to intake manifold and is located at the bottom of the manifold.
  6. Connect the GE 23738-A  to the vacuum reservoir and apply 34 kPa (10 inches Hg) of vacuum.
  7. Verify the reservoir holds vacuum for at least 10 s.
    • If the vacuum is not held for at least 10 s 

      Replace the intake manifold

    • If the vacuum is held for at least 10 s 
  8. Connect the vacuum hose to the reservoir.
  9. Disconnect the vacuum hose at the turbocharger bypass valve and connect the GE 23738-A  to the hose.
  10. Engine idling, command the Turbocharger Bypass Solenoid Valve ON and OFF with a scan tool.
    NOTE: The Q40 Turbocharger Bypass Solenoid Valve is supplied with vacuum from both the intake manifold and the vacuum reservoir at idle. The vacuum supply hose from the intake manifold must be disconnected before proceeding, to allow vacuum to bleed off when changing command states.
  11. Verify the vacuum toggles between 0 kPa (0 inches Hg) to greater than 45 kPa (13 inches Hg).
    • If not within the specified range 

      Test or replace the Q40 turbocharger bypass solenoid valve

    • If within the specified range 
  12. Connect any hoses that were disconnected during previous steps.
  13. Verify damage to the turbocharger bypass valve assembly does not exist. Refer to Turbocharger Cleaning and Inspection .
    • If the turbocharger bypass valve assembly is damaged 

      Repair or replace the turbocharger bypass valve assembly as necessary.

    • If the turbocharger bypass valve assembly is not damaged 
  14. Replace the turbocharger.