maintenance reset FORD MUSTANG 2003 Workshop Manual

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 canister to the engine intake
manifold during various engine operating modes. The EVAP canister purge valve is normally closed.
Evaporative Emission (EVAP) Canister
Fuel vapors from the fuel tank are stored in the EVAP canister. When the engine is running, the vapors
are purged from the EVAP canister for combustion.
Canister Vent Solenoid
During the Evaporative Emission (EVAP) System Test Monitor, Evaporative Emissions Repair
Verification Drive Cycle, and the Evaporative Emission System Leak Test, the canister vent solenoid is
closed to allow a vacuum to be drawn on the fuel tank at a specific level. The canister vent solenoid is
normally open.
Fuel Tank Pressure (FTP) Sensor
The fuel tank pressure sensor is used to measure the fuel tank pressure during the Evaporative
Emissions Monitor Test. The fuel tank pressure sensor is mounted in the fuel vapor control valve tube
as it crosses over the fuel tank.
Fuel Vapor Control Valve
The fuel vapor control valve is normally between the EVAP canister and the fuel vapor vent valve. Its
function is to prevent the flow of liquid fuel into the EVAP canister or up to the canister purge valve
during refueling, and to prevent the collection of liquid fuel in the fuel vapor hoses by overfilling the fuel
tank.
Fuel Vapor Vent Valve (FVV) Assembly
The fuel vapor vent valve (FVV) 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 intricate part of the fuel filler pipe. It is intended to prevent liquid
fuel from re-entering the fuel filler pipe from the fuel tank on refueling or roll over conditions.
Fuel Filler Cap
The fuel filler cap is used to prevent fuel spill and to close the EVAP system to the atmosphere.
Evaporative Emission 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 Emission System Leak Test Klj . 2 ba
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GENERAL PROCEDURES
Evaporative Emission Repair Verification Drive Cycle
Drive Cycle Recommendations
NOTE:
The following procedure is designed to execute and complete the evaporative emission repair
verification drive cycle and to clear the Ford P1000, inspection and maintenance (I/M) readiness code.
When the ambient air temperature is below 4.4°C (40°F) or above 37.8°C (100°F), or the altitude is
above 2,438 meters (8,000 feet), the EVAP monitor will not run. If the P1000 must be cleared in these
conditions, the powertrain control module (PCM) must detect them once (twice on some applications)
before the EVAP monitor can be bypassed and the P1000 cleared. The EVAP bypassing procedure is
described in the following drive cycle.
1. Most OBD II monitors will complete more readily using a steady foot driving style during cruise or acceleration modes. Operating the throttle in a smooth fashion will minimize the time
necessary for monitor completion.
2. Fuel tank level should be between one- half and three-quarters full with three- quarters full being
the most desirable.
3. The evaporative monitor can only operate during the first 30 minutes of engine operation. When executing the procedure for this monitor, stay in part throttle mode and drive in a smooth
fashion to minimize fuel slosh.
Drive Cycle Preparation
NOTE: For best results, follow each of the following steps as accurately as possible.
4. NOTE: This step bypasses the engine soak timer and resets OBD II monitor status.
Install the scan tool. Turn the key ON with the engine OFF. Cycle the key off, then on. Select
the appropriate vehicle and engine qualifier. Clear all diagnostic trouble codes (DTCs) and carry
out a PCM reset.
5. Begin to monitor the following PIDs: ECT, EVAPDC, FLI (if available) and TP MODE. Press Diagnostic Data Link, PCM, PID/Data monitor and record, press trigger to select each PID, then
start.
6. Start the engine without returning the key to the OFF position.
Preparation for Monitor Entry
WARNING: Strict observance of posted speed limits and attention to driving conditions
SECTION 303-
13: Evaporative Emissions 2003 Mustang Workshop Manual Special Tool(s)
Worldwide Diagnostic System
(WDS)
418-
F224,
New Generation STAR (NGS)
Tester
418- F052, or equivalent scan
tool Klj . 1 ba
32003 Mustang Workshop Manual
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