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Home >> Chevrolet >> 2012 >> Cruze Eco, Automatic Trans >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 5 (Engine Controls/Fuel - 1.8L - DTC Diagnostics, Troubleshooting & Diagnosis) >> Diagnostic Information and Procedures >> Fuel System Diagnosis >> Circuit/System Testing

Circuit/System Testing

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    NOTE:
    • The Fuel Pump Enable may need to be commanded ON a few times in order to obtain the highest possible fuel pressure.
    • DO NOT start the engine.
    • High fuel pressure readings may result due to hot soak fuel boiling. With the engine OFF, the fuel pressure may increase to the setting of the pressure relief regulator valve, approximately 580 kPa (84 PSI).
  1. Ignition ON, engine OFF, command the Fuel Pump Enable ON with a scan tool and observe the fuel pressure gauge while the fuel pump is operating. Verify the fuel pressure is between 276-448 kPa (40-65 PSI).
    • If the fuel pressure is less than the specified range, test, inspect, and repair the items listed below. If all items test normal, replace the fuel pump module.
    • Restricted fuel feed pipe
    • Inspect the harness connectors and the ground circuits of the fuel pump for poor connections.
  2. Verify that the fuel pressure does not decrease greater than 34 kPa (5 PSI) in 1 min.
    • If the fuel pressure decreases greater than the specified value, perform the following procedure:
    1. Ignition OFF, relieve the fuel pressure. Refer to Fuel Pressure Relief .
    2. Disconnect the chassis fuel feed hose from the engine compartment fuel pipe.
    3. Install the EN 37287  Fuel Line Shut-Off Adapters between the chassis fuel hose and the engine compartment fuel pipe.
    4. Open the valve on the EN 37287  Fuel Line Shut-Off Adapters.
    5. Ignition ON, command the Fuel Pump Enable ON with a scan tool and bleed the air from the CH 48027  Digital Pressure Gauge.
    6. Command the Fuel Pump Enable ON with a scan tool.
    7. Close the valve on the EN 37287  Fuel Line Shut-Off Adapters.
    8. Monitor the fuel pressure for 1 min.
      • If the fuel pressure does not decrease greater than 34 kPa (5 PSI) within the specified time, replace the fuel pump module.
  3. Relieve the fuel pressure to 69 kPa (10 PSI). Verify that the fuel pressure does not decrease greater than 14 kPa (2 PSI) in 5 min.
    • If the fuel pressure decreases greater than the specified value, replace the fuel pump module.
  4. Operate the vehicle within the conditions of the customer's concern while monitoring the fuel pressure with the CH 48027  Digital Pressure Gauge. The fuel pressure should not drop off during acceleration, cruise, or hard cornering.
    • If the fuel pressure drops off, test, inspect, and repair the items listed below. If all items test normal, replace the fuel pump module.
    • Restricted fuel feed pipe
    • Inspect the harness connectors and the ground circuits of the fuel pump for poor connections.
  5. If the fuel system tests normal, refer to Symptoms - Engine Controls .
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