2014 Mustang Workshop Manual

SECTION 310-00: Fuel System — General Information	2014 Mustang Workshop Manual
DIAGNOSIS AND TESTING	Procedure revision date: 01/07/2013

Fuel System

Special Tool(s)
	Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware, or equivalent scan tool

Principles of Operation

NOTE: The following procedure diagnoses a slow-to-fill concern only. For all other concerns, refer to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.

The fuel tank filler pipe assembly is used to refuel the vehicle. The fuel tank inlet check valve prevents spitback of fuel during and after refueling. The fuel tank stores the fuel. The fuel tank contains a Fuel Pump (FP) module. The FP module consists of a fuel level sender and a FP . The fuel level sender sends a signal to the fuel gauge informing the driver of how much fuel is in the fuel tank. The FP provides fuel to the fuel tubes which supply the fuel rail.

During refueling, the fuel tank vents to the atmosphere through the vent and filler pipes, on vehicles without On-Board Refueling Vapor Recovery (ORVR) systems. In vehicles equipped with ORVR , the fuel tank and filler pipe are designed so that when the vehicle is being refueled, fuel vapors in the fuel tank travel to the Evaporative Emission (EVAP) canister, which absorbs the fuel vapors and vents the pressure from the fuel tank during refueling.

Inspection and Verification

WARNING: Do not smoke, carry lighted tobacco or have an open flame of any type when working on or near any fuel-related component. Highly flammable mixtures are always present and may be ignited. Failure to follow these instructions may result in serious personal injury.

WARNING: Do not carry personal electronic devices such as cell phones, pagers or audio equipment of any type when working on or near any fuel-related component. Highly flammable mixtures are always present and may be ignited. Failure to follow these instructions may result in serious personal injury.

WARNING: When handling fuel, always observe fuel handling precautions and be prepared in the event of fuel spillage. Spilled fuel may be ignited by hot vehicle components or other ignition sources. Failure to follow these instructions may result in serious personal injury.

WARNING: Always disconnect the battery ground cable at the battery when working on an evaporative emission (EVAP) system or fuel-related component. Highly flammable mixtures are always present and may be ignited. Failure to follow these instructions may result in serious personal injury.

NOTE: Do not use incandescent lights when inspecting the fuel system. Use only flourescent or LED lighting.

Verify the customer concern by refueling the vehicle and observe the fuel fill rate.

Inspect to determine if any of the following mechanical concerns apply.

Visual Inspection Chart

Mechanical
Bent, kinked or damaged fuel tank filler pipe Bent, kinked or damaged fuel tank filler pipe vent tube (if equipped) Incorrect routing of the fuel tank filler pipe Incorrect routing of the fuel tank filler pipe vent tube (if equipped) Incorrect position of fuel tank filler pipe clamps Incorrect position of fuel tank filler pipe vent tube clamps (if equipped) Fuel tank mounted vapor tubes bent or damaged Evaporative Emission (EVAP) system tubes or hoses bent or damaged Accident damage to the fuel tank Accident damage to the vehicle affecting the fuel tank filler pipe-to-body connection Unauthorized modifications and/or alterations to the vehicle EVAP system fresh air hose plugged (dirt, spider webbing)

Mechanical

Bent, kinked or damaged fuel tank filler pipe
Bent, kinked or damaged fuel tank filler pipe vent tube (if equipped)
Incorrect routing of the fuel tank filler pipe
Incorrect routing of the fuel tank filler pipe vent tube (if equipped)
Incorrect position of fuel tank filler pipe clamps
Incorrect position of fuel tank filler pipe vent tube clamps (if equipped)
Fuel tank mounted vapor tubes bent or damaged
Evaporative Emission (EVAP) system tubes or hoses bent or damaged
Accident damage to the fuel tank
Accident damage to the vehicle affecting the fuel tank filler pipe-to-body connection
Unauthorized modifications and/or alterations to the vehicle
EVAP system fresh air hose plugged (dirt, spider webbing)

If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.

NOTE: Make sure to use the latest scan tool software release.
If the cause is not visually evident, connect the scan tool to the Data Link Connector (DLC).

NOTE: The Vehicle Communication Module (VCM) LED prove out confirms power and ground from the DLC are provided to the VCM .
If the scan tool does not communicate with the VCM :
- check the VCM connection to the vehicle.
- check the scan tool connection to the VCM .
- refer to Section 418-00 , No Power To The Scan Tool, to diagnose no power to the scan tool.

If the scan tool does not communicate with the vehicle:
- verify the ignition key is in the ON position.
- verify the scan tool operation with a known good vehicle.
- refer to Section 418-00 to diagnose no response from the PCM.

Carry out the network test.
- If the scan tool responds with no communication for one or more modules, refer to Section 418-00 .
- If the network test passes, retrieve and record Continuous Memory Diagnostic Trouble Codes (CMDTCs).

Clear the continuous DTCs and carry out the self-test diagnostics for the EVAP system using the scan tool.

If the DTCs retrieved are related to the concern, go to Evaporative Emission (EVAP) System DTC Chart. For PCM-related DTCs, refer to the Powertrain Control/Emissions Diagnosis (PC/ED) manual. For all other DTCs, refer to Section 419-10 .

If no DTCs related to the concern are retrieved, GO to Symptom Chart .

DTC Chart

Evaporative Emission (EVAP) System DTC Chart

DTC	Description	Action
P0446	Evaporative Emission System Vent Control Circuit	GO to Pinpoint Test A .
P0451	Evaporative Emission System Pressure Sensor/Switch Range/Performance	GO to Pinpoint Test A .
P0452	Evaporative Emission System Pressure Sensor/Switch Low	GO to Pinpoint Test A .
P0453	Evaporative Emission System Pressure Sensor/Switch High	GO to Pinpoint Test A .
P0454	Evaporative Emission System Pressure Sensor/Switch Intermittent	GO to Pinpoint Test A .
P1450	Unable to Bleed up Fuel Tank Vacuum	GO to Pinpoint Test A .
P1451	Evaporative Emission System Vent Control Circuit	GO to Pinpoint Test A .
P260F	Emission System Monitoring Processor Performance	GO to Pinpoint Test A .

Symptom Chart

Symptom Chart
Condition	Possible Sources	Action
Slow to fill	Fuel tank filler pipe Fuel tank filler pipe vent tube, if equipped Evaporative Emission (EVAP) system Fuel tank inlet check valve (part of the fuel tank) Fuel level vent valve, if equipped (part of the fuel tank)	GO to Pinpoint Test A .
All other fuel system concerns	Fuel system components	REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.

Pinpoint Test

Pinpoint Test A: Slow to Fill

Normal Operation

Under normal operation, fuel should flow at a steady rate through the fuel tank filler pipe into the fuel tank. As fuel enters the fuel tank, air is vented through the filler pipe or the On-Board Refueling Vapor Recovery (ORVR) system.

This pinpoint test is intended to diagnose the following:

Fuel tank filler pipe vent tube, if equipped
Fuel tank filler pipe
Evaporative Emission (EVAP) system
Fuel tank inlet check valve (part of the fuel tank)
Fuel level vent valve, if equipped (part of the fuel tank)

PINPOINT TEST A: SLOW TO FILL

Test Step	Result / Action to Take
A1 CARRY OUT INSPECTION AND VERIFICATION
Carry out Inspection and Verification. Was the cause of the concern found?	Yes REPAIR or INSTALL new components to correct the concern. No GO to A2 .
A2 CHECK THE SYSTEM FOR ANY EVAP DTCs
Connect the scan tool. Check the system for any of the following EVAP DTCs: P0446, P0451, P0452, P0453, P0454, P1450, P1451 and P260F. Are any of these DTCs present?	Yes REFER to Powertrain Control/Emissions Diagnosis (PC/ED) manual to diagnosis the EVAP system. No GO to A3 .
A3 MONITOR THE FTP WHILE FILLING THE FUEL TANK
Monitor the Fuel Tank Pressure (FTP) reference value while filling the fuel tank. Refer to the Reference Values in the Powertrain Control/Emissions Diagnosis (PC/ED) manual. Is FTP within specification?	Yes GO to A5 . No GO to A4 .
A4 MONITOR THE FTP WHILE FILLING THE FUEL TANK WITH THE EVAP SYSTEM DISCONNECTED
Disconnect the fuel tank-to- EVAP canister quick connect coupling at the EVAP canister. Monitor the FTP reference value while filling the fuel tank. Refer to Powertrain Control/Emissions Diagnosis (PC/ED) manual. Is FTP within specification?	Yes INSPECT the EVAP system for blockage or restrictions. REPAIR the blockage or restriction. If the blockage or restriction cannot be repaired, INSTALL new EVAP system components. No GO to A5 .
A5 CHECK THE FUEL TANK FILLER PIPE ASSEMBLY FOR BLOCKAGE OR RESTRICTION
Remove the fuel tank filler pipe assembly. Refer to Section 310-01 . Inspect the fuel tank filler pipe and fuel tank filler pipe vent tube (if equipped) for a blockage or restriction. Is the fuel tank filler pipe or fuel tank filler pipe vent tube (if equipped) blocked or restricted?	Yes If possible, REPAIR the blockage or restriction. If the blockage or restriction cannot be repaired, INSTALL a new fuel tank filler pipe or fuel tank filler pipe vent tube. No GO to A6 .
A6 CHECK THE FUEL TANK INLET CHECK VALVE
Inspect the fuel tank inlet check valve for restriction or sticking. Is the fuel tank inlet check valve restricted or sticking?	Yes If possible, REPAIR the restrictions. If the restriction cannot be repaired, INSTALL a new fuel tank. REFER to Section 310-01 . No INSTALL a new fuel tank. REFER to Section 310-01 .