Ford Escape Quiz
Powertrain

Diagnosis and Testing - Fuel System

In this manual: Powertrain
General Information — 26Chassis — 160Powertrain — 323Electrical — 356Body and Paint — 290
~9min read

Diagnostic Trouble Code (DTC) Chart

The diagnosis in this manual assumes a certain level of skill and knowledge of Ford-approved diagnostic procedures.
REFER TO: Diagnostic Methods (100-00 General Information, Description and Operation).


Module Trouble Code Description Action
PCM P04B0:00 Refueling Vapor Control Valve Circuit/Open: no subtype information GO to Pinpoint Test B
PCM P04B4:00 Refueling Vapor Control Valve Stuck Closed: no subtype information GO to Pinpoint Test C
PCM P144B:00 EVAP system secondary purge vapor line blocked/restricted: no sub-type information GO to Pinpoint Test A
PCM P24C0:00 EVAP system leak detection pump changeover valve stuck on: no sub-type information GO to Pinpoint Test A

Global Customer Symptom Codes (GCSC) Table

The diagnosis in this manual assumes a certain level of skill and knowledge of Ford-approved diagnostic procedures.
REFER TO: Diagnostic Methods (100-00 General Information, Description and Operation).


Symptom Action
Start/Run/Move > Fluids > Fuel > Slow Fill/Premature Shutoff GO to Pinpoint Test A
Start/Run/Move > Fluids > Fuel > Slow Fill/Premature Shutoff GO to Pinpoint Test B

Pinpoint Test(s)


DIAGNOSTIC TEST A: SLOW FILL

Normal Operation and Fault Symptoms

DTC Fault Trigger Conditions

Trouble Code Description Fault Trigger Condition
PCM P144B:00 EVAP system secondary purge vapor line blocked/restricted: no sub-type information Evaporative Emission System Secondary Purge Vapor Line Restricted/Blocked
PCM P24C0:00 EVAP system leak detection pump changeover valve stuck on: no sub-type information Evaporative Emission System Leak Detection Pump Changeover Valve Stuck On

Possible Sources

  • Fuel tank filler pipe
A1 CHECK FUEL SYSTEM COMPONENTS FOR DAMAGE
  • Visually inspect the following components for signs of damage:
    • Fuel tank filler pipe
    • Fuel tank filler tube vent hose, if equipped
    • EVAP system (look for kinked or crushed vapor lines)
    • Fuel tank inlet check valve (part of the fuel tank)
    • Fuel level vent valve (part of the fuel tank)
    • EVAP canister (may be saturated with liquid)

Is any of the components damaged?
Yes REPAIR or INSTALL new components to correct the condition.
No GO to A2
A2 CHECK THE SYSTEM FOR ANY DTC (DIAGNOSTIC TROUBLE CODE)
  • Using the diagnostic scan tool, perform a PCM self-test.
  • Check for any of the following DTCs: P25B0, P0461, P0462, P0463.

Are any DTCs indicated?
Yes If DTCs are present, correct the related condition. Refer to the Repair Manual.
No If no DTCs are present, go to A3.
A3 CHECK THE SYSTEM FOR ANY EVAP (EVAPORATIVE EMISSIONS) DTCS
  • Using the diagnostic scan tool, perform a PCM self-test.
  • Check the PCM for any of the following EVAP DTCs: P00FE, P04B4, P04F0, P0496, P24BE, P24BF, P24C1, P144B, P2418, P2450, P2451, P0451, P0452 and P0453.

Are any EVAP system DTCs present?
Yes If DTCs are present, correct the related condition.
No GO to A4
A4 MONITOR FTP DURING FUEL TANK FILL
  • Monitor the fuel tank pressure (FTP) to typical diagnostic reference values during fuel tank refilling.

FTP less than 1 inch H2O / 0.25 kPa?
Yes GO to A5
No FTP less than 12 inches H2O / 3.0 kPa?
Yes: GO to A6
No: GO to A7
A5 CHECK THE FUEL FILLER PIPE AND VAPOR RECIRCULATION LINE ASSEMBLY
  • Disconnect the fuel tank filler tube from the fuel tank.
  • Inspect the fuel tank filler tube for damage or blockage.

Is the fuel tank filler tube blocked or damaged?
Yes Replace the fuel tank filler tube assembly.
REFER TO: Fuel Tank Filler Pipe (310-01C Fuel Tank and Lines, Removal and Installation).
No Replace the fuel tank assembly.
REFER TO: Fuel Tank (310-01C Fuel Tank and Lines, Removal and Installation).
A6 REFUEL USING A DIFFERENT FUEL NOZZLE
  • Using a different fuel pump nozzle, monitor the fuel tank pressure (FTP) to typical diagnostic reference values while filling the fuel tank.

FTP less than 12 inches H2O / 3.0 kPa?
Yes System OK - the root cause cannot be determined at this time.
No GO to A7
A7 DIAGNOSE THE FRESH AIR HOSE
  • Disconnect the fresh air line from the Evaporative Leak Detection Pump (ELDP).

Is the fresh air hose blocked or damaged?
Yes Repair or replace the fresh air hose.
No GO to A8
A8 PERFORM EVAPORATIVE LEAK DETECTION PUMP (ELDP) DIAGNOSIS
  • Disconnect the Evaporative Leak Detection Pump (ELDP) from the evaporator canister.
  • Monitor the fuel tank pressure (FTP) to typical diagnostic reference values during fuel tank refilling.

FTP less than 12 inches H2O / 3.0 kPa?
Yes Remove/replace the Evaporative Leak Detection Pump (ELDP).
Refer to: Evaporative Emission System Leak Test (303-13C Evaporative Emissions, General Procedures).
No GO to A9
A9 EVAPORATOR DESIGNER DIAGNOSTICS
  • Disconnect the EVAP canister from the fuel vapor loading line.
  • Monitor the fuel tank pressure (FTP) to typical diagnostic reference values during fuel tank refilling.

FTP less than 12 inches H2O / 3.0 kPa?
Yes Remove/replace the EVAP canister.
Refer to: Evaporative Emission Canister Purge Valve (303-13C Evaporative Emission System, Removal and Installation).
No Remove/replace the fuel vapor hose, including the Fuel Vapor Vent Valve (FVVV) and the Tank Pressure Control (TPC) valve.
DIAGNOSTIC TEST B: DTC P04B0

Refer to Wiring Diagrams, Cell 023, for schematic and connector information.

Normal Operation and Fault Symptoms

DTC Fault Trigger Conditions

Trouble Code Description Fault Trigger Condition
DTC P04B0:00 Refueling Vapor Control Valve Circuit/Open: no subtype information Fuel Vapor Vent Valve (FVVV) Circuit

Possible Sources

  • Wiring, Terminals and Connectors

Visual Inspection and Pre-checks

  • Fuel Vapor Vent Valve FVVV (also known as the Refueling Valve (RV))
B1 CHECK THE SYSTEM FOR ANY EVAPORATION (EVAP EMISSIONS) DTCS
  • Using the diagnostic scan tool, perform the KOEO self-test on the PCM.

Is DTC P04B0 present?
Yes GO to B2
No Look for circuit wiring concerns and repair as necessary.
B2 CHECK THE FVVV (ALSO KNOWN AS REFUELING VALVE) VENT VALVE CIRCUIT FOR AN OPEN:
  • Using the diagnostic scan tool, perform the KOEO self-test on the PCM.
  • Ignition OFF.
  • Disconnect the Fuel Vapor Vent Valve (FVVV) connector C441.
  • Check the resistance at the Fuel Vapor Vent Valve.
  • Measure the resistance as shown:
    Click to display connectors
    Positive lead Measurement/Action Negative lead
    C441-1 C441-2

Is the resistance within 7.5 - 9.5 Ohms?
Yes GO to B3
No Replace the FVVV (Fuel Vapor Vent Valve).
B3 CHECK THE FVVV (ALSO KNOWN AS REFUELING VALVE) FUEL VAPOR VENT VALVE CIRCUIT FOR A SHORT TO VOLTAGE:
  • The ignition is on.
  • Reconnect the Fuel Vapor Vent Valve (FVVV) connector C441.
  • Ignition crank or run condition.
  • Measure the voltage as shown:
    Click to display connectors
    Positive lead Measurement/Action Negative lead
    C441-1 C1381B-2

Is there voltage present?
Yes Circuit is shorted to voltage and must be repaired.
No Perform a visual inspection of the connector contacts and FVVV pins for visible damage and repair as necessary.
B4 CHECK THE FVVV (ALSO KNOWN AS REFUELING VALVE) FUEL VAPOR VENT VALVE CIRCUIT FOR A SHORT TO GROUND:
  • Ignition OFF.
  • Disconnect the Fuel Vapor Vent Valve (FVVV) connector C441.
  • Measure the resistance as shown:
    Click to display connectors
    Positive lead Measurement/Action Negative lead
    C441-1 Ground

Is the resistance greater than 10000 ohms?
Yes The concern is intermittent. Look for visual signs of damage to the connector contacts and FVVV pins.
No Look for circuit wiring concerns and repair as necessary.
B5 CHECK THE FUEL VAPOR VENT VALVE (ALSO KNOWN AS REFUELING VALVE) CIRCUIT FOR AN OPEN:
  • Ignition OFF.
  • Disconnect PCM C175E.
  • Disconnect the Fuel Vapor Vent Valve (FVVV) connector C441.
  • Measure the resistance as shown:
    Click to display connectors
    Positive lead Measurement/Action Negative lead
    C441-1 C175E-24

Is the resistance less than 3 ohms?
Yes The concern is intermittent. Look for visual signs of damage to the connector contacts and FVVV pins.
No Look for circuit wiring concerns and repair as necessary.
DIAGNOSTIC TEST C: P04B4

Normal Operation and Fault Symptoms

Refer to: Fuel System - General Information (310-00C Fuel System - General Information, Description and Operation).

DTC Fault Trigger Conditions

Trouble Code Description Fault Trigger Condition
DTC P04B4:00 Refueling Vapor Control Valve Stuck Closed: no subtype information Refueling Valve (RV) Stuck Closed

Possible Sources

  • Fuel Filler Neck
  • FTP Sensor
  • Fuel Vapor Vent Valve
C1 CHECK THE REFUELING VALVE IS CLOSED
  • Press the refueling door request button.
  • Confirm the FTP_H2O PID.

Does the tank pressure drop below 0.25 psi (6.92 in H2O)?
Yes GO to C3
No GO to C2
C2 CHECK THE FTP (FUEL TANK PRESSURE) SENSOR VOLTAGE WITH THE FUEL TANK FILLER TUBE OPEN.
  • Carefully open the fuel tank cap using the mechanical release lever located in the luggage compartment.
  • Install the supplemental refueling adapter supplied with the vehicle to open the fuel filler neck without the cap.
  • KOEO
  • Access the PCM and monitor the FTP (VOLT) PID.

    Access the PCM and monitor the FTP_V (V) PID.


Is the FTP (Fuel Tank Pressure) voltage within 1.4-1.54 V?
Yes GO to C3
No INSTALL a new FTP sensor.
Refer to: Fuel Tank Pressure Sensor and Tube - Hybrid Electric Vehicle (HEV) (303-13C Evaporative Emissions, Removal and Installation).
C3 CHECK THE FVVV CIRCUIT FOR AN OPEN
  • Using the diagnostic scan tool, perform the KOEO self-test on the PCM.
  • Ignition OFF.
  • Disconnect the Fuel Vapor Vent Valve (FVVV) connector C4287.
  • Disconnect PCM connector C175E. C4287.
  • Check the resistance at the Fuel Vapor Vent Valve.
  • Measure the resistance as shown:
    Click to display connectors
    Positive lead Measurement/Action Negative lead
    C4287-1 C4287-2

Is the resistance within 7.5 - 9.5 Ohms at 14 V DC?
Yes GO TO C4
No Replace the FVVV (Fuel Vapor Vent Valve).
C4 CHECK THE FVVV CIRCUIT FOR A SHORT TO VOLTAGE
  • Ignition OFF.
  • Disconnect the fuel tank vapor vent valve C4287.
  • KOEO
  • Action:
    Positive lead Measurement/Action Negative lead
    Fuel Vapor Vent Valve (FVVV) C4287-1 C175E-24

Is the resistance less than 5 ohms?
Yes GO to C5
No Repair the circuit open. Clear the PCM DTCs. REPEAT the self-test.
C5 CHECK THE FUEL VAPOR VENT VALVE (ALSO KNOWN AS REFUELING VALVE) CIRCUIT FOR A SHORT TO GROUND
  • Ignition OFF.
  • Ignition crank or run condition.
  • Measure the voltage as shown.
    Positive lead Measurement/Action Negative lead
    Fuel Vapor Vent Valve (FVVV) C4287-2 Ground
    Fuel Vapor Vent Valve (FVVV) C4287-1 Ground

Is the voltage greater than 11 volts?
Yes The concern is intermittent. Look for visual signs of damage to the connector contacts and FVVV pins. Clear the DTCs and send the vehicle out.
No Look for circuit wiring concerns and repair as necessary.

Test yourself

A quick Ford Escape quiz: every answer comes with an explanation and a link to the manual page.