Vibe FWD L4-1.8L (2010)
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 fuel supply system is a returnless design. Most of the fuel system components are located inside the fuel tank. When the ignition switch is turned to
the START position and the engine is cranking, the circuit opening relay energizes the fuel pump. The fuel pump will continue to operate if the
powertrain control module (PCM) receives a reference signal when the engine is started. The fuel pump operates as long as the circuit opening relay is
energized by the PCM. When the circuit opening relay is de-energized, the fuel pump will stop operating. The fuel pump delivers fuel to the fuel rail at
high pressure. The fuel pressure regulator, located in the fuel tank, is responsible for keeping the fuel pressure at 301-347 kPa (44-50 psi).
Diagnostic Aids
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Monitoring the misfire current counters, or misfire graph, may help to isolate the fuel injector that is causing the condition.
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Operating the vehicle over a wide temperature range may help isolate the fuel injector that is causing the condition.
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If you were sent here by a DTC P0300 and all the injectors test normal, the Misfire Current Cylinder or Misfire Graphic information on a scan tool
can be used to determine which injector circuit should be examined in detail.
Reference Information
Schematic Reference
Engine Controls Schematics (See: Diagrams/Electrical Diagrams)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
Fuel System Description (See: Computers and Control Systems/Description and Operation/Fuel System Description)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Computers and Control Systems/Testing and Inspection/Diagnostic Trouble Code
Descriptions/Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Special Tools
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J 34730-1A Fuel Pressure Gage
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J 42982 Fuel Pressure Gage Adapter
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J 37287 Fuel Line Shut-Off Adapters
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 adequate 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.
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DO NOT start the engine.
1. Ignition ON, command the fuel pump relay ON with a scan tool. You should hear the fuel pump turn ON and OFF.
‹› If the 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).
