Cruze L4-1.4L Turbo (2011)
Fuel Pressure: Testing and Inspection
Fuel System Diagnosis
Fuel System Diagnosis
Diagnostic Instructions
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Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
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Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
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Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure Instructions
)provides an overview of each diagnostic category.
Circuit/System Description
When the ignition is turned ON, the engine control module (ECM) supplies power to the in-tank fuel pump, by energizing the fuel pump relay. The
in-tank fuel pump remains ON as long as the engine is cranking or running and the ECM receives crankshaft reference pulses. If there are no reference
pulses, the ECM turns the in-tank fuel pump OFF, 2 s after the ignition switch is turned ON or 2 s after the engine stops running. The electric fuel pump
is incorporated into the modular fuel pump and sender assembly and is located inside the fuel tank. The fuel pump supplies fuel through a fuel filter, also
located in the modular fuel pump and sender assembly, through the fuel feed pipes, to the fuel rail assembly. The fuel pump provides fuel at a pressure
above the pressure needed by the fuel injectors. The fuel pressure regulator, located in the modular fuel pump and sender assembly, keeps the fuel
available to the fuel injectors at a regulated pressure. When the fuel pressure rises above the pressure regulator calibration, the pressure is relieved, with
excess fuel exhausted into the modular fuel pump and sender assembly reservoir.
Reference Information
Description and Operation
Fuel System Description (See: Computers and Control Systems/Description and Operation/Fuel System Description)
Electrical Information Reference
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Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit
Testing/Circuit Testing)
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Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Connector
Repairs/Connector Repairs)
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Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General
Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)
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Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring
Repairs/Wiring Repairs)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning)for scan tool information
Special Tools
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CH 48027 - Digital Pressure Gauge
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EN 37287 - Fuel Line Shut-Off Adapters
For equivalent regional tools, refer to Special Tools (See: Computers and Control Systems/Tools and Equipment).
Circuit/System Verification
Note:
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Inspect the fuel system for damage or external leaks before proceeding.
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Verify that an adequate amount of fuel is in the fuel tank before proceeding.
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The fuel pump relay may need to be commanded ON a few times in order to obtain the highest possible fuel pressure.
1. Ignition ON, command the KR23A Fuel Pump Relay ON with a scan tool. You should hear the G12 Fuel Pump turn ON and OFF.
‹› If the G12 Fuel Pump does not turn ON, refer to Fuel Pump Electrical Circuit Diagnosis (See: Computers and Control Systems/Testing and
Inspection/Component Tests and General Diagnostics/Fuel Pump Electrical Circuit Diagnosis).
2. Ignition OFF, all accessories OFF, install the CH 48027 - Digital Pressure Gauge.
3. Ignition ON, command the KR23A Fuel Pump Relay ON with a scan tool. Verify the fuel pressure is between 250-450 kPa (36-65 PSI) and
remains steady for 5 m.