Regal L4-2.0L 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
The engine control module (ECM) supplies voltage to the fuel pump flow control module when the ECM detects that the ignition is ON. The voltage
signal from the ECM to the fuel pump flow control module remains active for 2 s, unless the engine is in Crank or Run. While this voltage is being
received, the fuel pump flow control module closes the ground switch of the fuel pump and also supplies a varying voltage to the fuel tank pump module
in order to maintain the desired fuel rail pressure.
The fuel system is an electronic returnless on-demand design. A returnless fuel system reduces the internal temperature of the fuel tank by not returning
hot fuel from the engine to the fuel tank. Reducing the internal temperature of the fuel tank results in lower evaporative emissions.
The fuel tank stores the fuel supply. An electric turbine style fuel pump attaches to the fuel tank fuel pump module inside the fuel tank. The fuel pump
supplies fuel through the fuel feed pipe to the high pressure fuel pump. The fuel pump also supplies fuel to a venturi pump located on the bottom of the
fuel tank fuel pump module. The function of the venturi pump is to fill the fuel tank fuel pump module reservoir. The fuel tank fuel pump module
contains a reverse flow check valve. The check valve maintains fuel pressure in the fuel feed pipe in order to prevent long cranking times.
Diagnostic Aids
The fuel injectors are calibrated to begin operating at these pressures:
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0.8 Mpa (116 psi) at 20-32°C (68-90°F) with nonblended gasoline
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2.45 Mpa (355 psi) at 20°C (68°F) with E85 blended gasoline
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2.35 Mpa (341 psi) at 24°C (75°F) with E85 blended gasoline
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2.2 Mpa (319 psi) at 32°C (90°F) with E85 blended gasoline
These specifications will vary when the temperature is outside of this range.
Reference Information
Description and Operation
Fuel System Description (See: Powertrain Management/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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J 37287 - Fuel Line Shut-Off Adapter
For equivalent regional tools, refer to Special Tools (See: Powertrain Management/Computers and Control Systems/Tools and Equipment).
