Ford Freestar 2004, 2004 Monterey Workshop Manual
Evaporative Emission (EVAP) Canisters
SECTION 310-00: Fuel System 2004 Freestar/Monterey Workshop Manual
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DIAGNOSIS AND TESTING
Procedure revision date: 07/31/ 2003
Evaporative Emissions
Printable View (184 KB)
Special Tool(s)
Worldwide Diagnostic System (WDS)
418-F224
New Generation STAR (NGS) Tester
418-F052, or equivalent scan tool
Evaporative Emission System Leak Tester
310-F007 (134-00056) or equivalent
The EVAP running loss system leak test:
utilizes intake manifold vacuum to test the system and involves several stages.
Evaporative Emission System
Item Part Number Description
1 9030 Fuel filler cap
2 9C052 Fuel tank pressure sensor
3 9B190 RIU limit vent valve
4 9C915 Evaporative emission canister purge valve
5 9F945 Canister vent solenoid
6 9B328 Evaporative emission dust separator
7 9D653 Evaporative emission canister
8 9002 Fuel tank
9 9B593 Fuel vapor vent valve
10 9189 Fuel filler pipe check valve
Principles of Operation
Evaporative Emission (EVAP) Canister Purge Valve
The EVAP canister purge valve is controlled by the powertrain control module (PCM). The EVAP canister purge valve controls the flow of fuel vapors from the EVAP
canisters to the engine intake manifold during various engine operating modes. The EVAP canister purge valve is normally closed.
Fuel vapors from the fuel tank are stored in the EVAP canisters. When the engine is running, the vapors are purged from the EVAP canisters for combustion.
EVAP canisters or vent solenoid
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Canister Vent Solenoid
During the Evaporative Emission Running Loss System Monitor Test, Evaporative Emissions Repair Verification Drive Cycle, and the Evaporative Emission System
Leak Test, the canister vent solenoid is closed to allow either a vacuum to be drawn on the fuel tank or to hold a specified pressure in the system. The canister vent
solenoid is normally open.
Fuel Tank Pressure (FTP) Sensor
The fuel tank pressure (FTP) sensor is used to measure the fuel tank pressure during the Evaporative Emissions Monitor Test. It is also used to control excessive fuel
tank pressures by forcing the EVAP system to purge. The fuel tank pressure sensor is mounted in the main vapor line.
Fuel Vapor Vent (FVV) Valve Assembly
The fuel vapor vent (FVV) valve assembly is mounted on the top of the fuel tank. It is used to control the flow of fuel vapors entering the EVAP system. The head portion
of the assembly prevents the fuel tank from overfilling during refueling. The assembly also has a spring float, which prevents liquid fuel from entering the vapor delivery
system under severe handling or vehicle rollover conditions. In the upright position, the open bottom of the float will lift and shut off the orifice. Under severe handling
conditions, the spring will push the float closed when angles allow liquid fuel to reach the orifice. In a rollover condition, the weight of the open bottom float and spring
pressure will close the orifice.
Fuel Filler Pipe Check Valve
The fuel filler pipe check valve is an integral part of the fuel tank or the fuel filler pipe. It is intended to prevent liquid fuel from re-entering the fuel filler pipe from the fuel
tank after refueling.
Fuel Filler Cap
The fuel filler cap is used to prevent fuel spill and to close the EVAP system to the atmosphere.
Fill Limit Vent Valve (FLVV)
The fill limit vent valve is mounted on top of the fuel tank. It has a main orifice which allows fuel vapor to route to the carbon canisters during refueling. This orifice is
controlled by a float, when the tank is full the flow of vapor is stopped and prevents the tank from overfilling.
Evaporative Emission (EVAP) System Monitor
When a fault occurs, the EVAP system monitor is reset to NO and a diagnostic trouble code (DTC) is set in the PCM memory. After the DTC is repaired, the vehicle
drive cycle must be completed to reset the monitor in preparation for inspection and maintenance testing.
EVAP Running Loss System Leak Test
To start the testing, conditions of stable purging and vehicle speed must be satisfied. During the first stage, the EVAP canister vent solenoid is closed, while the EVAP
canister purge valve remains open, applying and building vacuum in the system as indicated by the FTP sensor. This phase checks for major leaks in the EVAP system.
In the second stage, the EVAP canister purge valve closes and the system looks for minimal decay rate in the vacuum, indicating the absence of any small EVAP
system leaks.
The last stage is entered only if stage two of the leak test has failed and checks whether the failed test was due to excess vapor generation. It monitors fuel vapor
generation rate. Initially, the canister vent solenoid is opened to equalize EVAP system pressure to atmosphere. Then the canister vent solenoid is closed, allowing
pressure to build if vapor generation is present in sufficient quantity. If the rate of generation is found to be too high, the EVAP running loss system leak test is aborted.
If not, then a small leak is diagnosed.
Inspection and Verification
1. Verify the customer concern is with the evaporative emission (EVAP) system.
2. Visually inspect for the following obvious signs of mechanical damage.
Visual Inspection Chart
Mechanical
Fuel filler cap
EVAP test port
EVAP canister lines or hoses
Vacuum lines or hoses
3. If the concern remains after the inspection, connect the scan tool to the data link connector (DLC) located beneath the instrument panel and select the vehicle to
be tested from the scan tool menu. If the scan tool does not communicate with the vehicle:
check that the program card is correctly installed.
check the connections to the vehicle.
check the ignition switch position.
4. If the scan tool still does not communicate with the vehicle, refer to the scan tool manual.
5. Carry out the DATA LINK DIAGNOSTICS test. If the scan tool responds with:
CKT914, CKT915 or CKT70 = ALL ECUS NO RESP/N OT EQUIP, refer to Section 418-00.
NO RESP/NOT EQUIP for PCM, refer to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.
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SYSTEM PASSED, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs and carry out the PCM KOEO selftest.
6. If the DTCs retrieved are related to the concern, go to the PCM Diagnostic Trouble Code (DTC) Index to continue diagnostics.
7. If the concern remains after the inspection, determine the symptom. GO to Symptom Chart.
PCM Diagnostics Trouble Code (DTC) Index
DTC Description Source Action
P0442
Small Leak Detected in EVAP Systema
P0457 Cap Off PCM GO to Pinpoint Test A.
P0456 Very Small Leak Detected in EVAP System PCM GO to Pinpoint Test A.
P0455 Major Leak or no Flow Detected PCM GO to Pinpoint Test B.
P1443 Very Small or no Purge Flow Detected PCM GO to Pinpoint Test B.
P1450 Excessive Vacuum Detected in the Fuel Tank PCM GO to Pinpoint Test C.
— Any Other PCM DTC PCM REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual.
a
As small as 1.02 mm (0.040 in).
Symptom Chart
SYMPTOM CHART
Condition Possible Sources Action
Hissing sound when
removing fuel cap
Excessive fuel odor
Slow fuel fill
Canister vent solenoid.
Evaporative emissions canisters.
Fuel vapor control valve tube assembly.
EVAP canister tube.
EVAP canister purge outlet tube.
Canister vent solenoid.
Evaporative emissions canisters.
Fuel vapor control valve tube assembly.
Evaporative emissions test port.
EVAP canister purge outlet tube.
Restriction in the canister vent solenoid, dust filter, carbon canisters and
canister attachment hoses or vent tubing.
Restriction in the fuel fill hose or fuel fill pipe.
Pinpoint Tests
NOTE: Reinstall or install new evaporative emission hose clamps removed or damaged during testing procedures.
PINPOINT TEST A: DTC P0442 SMALL LEAK IN EVAP SYSTEM
NOTE: Condition P0442 DTC set: less than 0.625 kPa (2.5 inches H2O) bleed-up over 15 seconds at 75% fuel fill. Vapor generation limit: more than 0.625 kPa (2.5
inches H2O) over 120 seconds.
PCM GO to Pinpoint Test A.
GO to Pinpoint
Test D.
GO to Pinpoint
Test E.
GO to Pinpoint
Test C.
Test Step Result / Action to Take
A1 VISUALLY INSPECT THE COMPONENTS FOR
SMALL LEAKS
Check for the presence of a fuel filler cap. Do not
tighten or check for correct installation at this time.
Verify the canister vent solenoid is correctly seated
on the EVAP canister.
Check for cut or loose connections to fuel vapor
hoses, tubes and connections in the following
locations:
EVAP canisters to EVAP canister purge valve
EVAP canister to fuel vapor vent valve
assembly
Check the fuel filler pipe for damage.
Is a concern with a hose, tube, connection or
valve visually evident?
A2 CHECK AT THE EVAP TEST PORT FOR SMALL
SYSTEM LEAKS
Disconnect and plug the evaporative emission return
tube at the intake manifold.
Complete the evaporative emission system leak test.
Refer to Evaporative Emission System Leak Test in
this section.
Does the system pass the leak test?
A3 VISUALLY INSPECT THE FUEL FILLER CAP
Yes
REPAIR or INSTALL new components as necessary. GO to A2.
No
GO to A2.
Yes
GO to A3.
No
GO to A4.
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