WARNING: BEFORE SERVICING OR REPLACING ANY COMPONENTS IN THE FUEL SYSTEM, REDUCE THE POSSIBILITY OF INJURY OR FIRE BY FOLLOWING DIRECTIONS IN FUEL SYSTEM WARNING, CAUTION AND NOTE AT THE BEGINNING OF THIS PINPOINT TEST.
Key on, engine off for 5 seconds.
Key off.
Visually inspect the complete fuel delivery system, including fuel lines, connections, fuel rail, pressure regulator and fuel injector areas for leaks (hissing noise), looseness, cracks, kinks, pinching, or abrasion caused by a collision or mishandling.
Visually inspect electrical harness and connectors for loose pins, corrosion, abrasion or other damage from collision or mishandling.
Verify vehicle has followed maintenance schedule.
Inspect fuel filter element for contamination and service as necessary.
Verify Inertia Fuel Shutoff (IFS) switch is set.
Verify vehicle battery is fully charged.
Verify electrical/fuse integrity.
Have any concerns been identified? Yes
REPAIR as necessary. VERIFY symptom no longer exists.
Record fuel tank pressure reading and fuel gauge reading.
Is the fuel pressure reading greater than 3,448 kPa (500 psi)? Yes
KEY OFF. GO to HB5
.
No
VERIFY fuel level. If OK, CHECK for power at tank solenoid valve. GO to HB3
.
HB3 CHECK FSV PWR AND GND CIRCUITS TO THE FUEL TANK SOLENOID SHUT-OFF VALVE
Key on.
Access Output Test Mode.
Select ALL ON.
Note: Measurement must be made within 7 seconds of activating test mode
Measure voltage between the FSV PWR and GND circuits at the fuel tank solenoid shut-off valve harness connector (refer to the Electrical and Vacuum Troubleshooting Manual for location).
Is the voltage reading greater than 10.5 volts? Yes
Select ALL ON and then START and STOP several times by toggling the START and STOP button on the scan tool and listening or feeling for a click at the fuel rail solenoid shut-off valve.
Key off.
Was a click of the solenoid valve felt or heard? Yes
REPLACE fuel rail pressure sensor. VERIFY symptom no longer exists.
No
GO to HB8
.
HB8 CHECK FSV PWR AND GND CIRCUITS TO THE FUEL RAIL SOLENOID SHUT-OFF VALVE
Key on, engine off.
Access Output Test Mode.
Select ALL ON, and START.
Measure the voltage between the FSV PWR and GND circuit at the fuel rail solenoid shut-off valve harness connector.
Note: This circuit remains on for only 7 seconds. Is the voltage reading greater than 10.5 volts? Yes
REPLACE fuel rail solenoid valve. VERIFY symptom no longer exists.
No
GO to HB9
.
HB9 CHECK FOR OPEN GND CIRCUIT TO FUEL RAIL SOLENOID SHUT-OFF VALVE
Measure the resistance between the GND circuit at the fuel rail solenoid shut-off valve harness connector and battery negative post.
Is resistance less than 5 ohms? Yes
REPAIR open FSV PWR circuit. VERIFY symptom no longer exists.
No
REPAIR open GND circuit. VERIFY symptom no longer exists.
KEY OFF. REPLACE fuel injector(s) that does not meet pressure specification. VERIFY symptom no longer exists.
HB16 FUEL LEAK CHECK
Possible causes:
Loose fitting connectors.
Damaged or worn seals or fittings.
Damaged fuel lines or fuel system components.
Note: After the vehicle has soaked for several hours (has not run), a slight natural gas smell may emanate from within the intake manifold and intake air system. This is normal, as the fuel injectors leak down from the fuel rail to the intake manifold over several hours.
Key on, engine off (verify pressure is greater than 586 kPa (85 psi)). If the fuel system does have a fuel leak, it will be necessary to repeat this step to maintain pressure.
Check for leaks with the natural gas sniffer provided in Rotunda tool kit 134-00114 or a soapy water solution such as Snoop. Cover the complete joint with this solution. Examine the components or joints for 60 seconds for signs of bubbles.
Are any leaks indicated? Yes
VERIFY proper torque on suspect fuel system components. RECHECK for leaks. If leaks still exist, REPAIR or REPLACE as necessary.
No
No leaks detected. No further diagnostics are required.
