fuel pressure FORD MUSTANG 2003 Owners Manual

DESCRIPTION AND OPERATION
Transmission Electronic Control System
The powertrain control module (PCM) and its input/output network control the following transmission
operations:
zShift timing
z Line pressure (shift feel)
z Torque converter clutch
The transmission control is separate from the engine control strategy in the PCM, although some of
the input signals are shared. When determining the best operating strategy for transmission operation,
the PCM uses input information from certain engine- related and driver-demand related sensors and
switches.
In addition, the PCM receives input signals from certain transmission- related sensors and switches.
The PCM also uses these signals when determining transmission operating strategy.
Using all of these input signals, the PCM can determine when the time and conditions are right for a
shift, or when to apply or release the torque converter clutch (TCC). It will also determine the best line
pressure needed to optimize shift feel. To accomplish this, the PCM uses hydraulic solenoids to control
transmission operation.
The following provides a brief description of each of the sensors and actuators used to control
transmission operation.
Powertrain Control Module (PCM)
The operation of the transmission is controlled by the powertrain control module (PCM). Many input
sensors provide information to the PCM. The PCM then controls actuators which determine
transmission operation.
Air Conditioning (A/C) Clutch
An electromagnetic clutch is energized when the clutch cycling pressure switch closes. The switch is
located on the suction accumulator/drier. The closing of the switch completes the circuit to the clutch
and draws it into engagement with the compressor driveshaft. When the A/C clutch is engaged,
electronic pressure control (EPC) is adjusted by the PCM to compensate for additional load on the
engine.
Brake Pedal Position (BPP) Switch
The brake pedal position (BPP) switch tells the PCM when the brakes are applied. The torque
converter clutch disengages when the brakes are applied. The BPP switch closes when the brakes are
applied and opens when they are released.
Engine Coolant Temperature (ECT) Sensor
The engine coolant temperature (ECT) sensor detects temperature of engine coolant and supplies the
information to the powertrain control module. The ECT sensor is used to control torque converter
clutch (TCC) operation. The ECT is installed in the heater outlet fitting or cooling passage on the
engine. For engine control applications, the ECT signal is used to modify ignition timing, EGR flow and
air- to-fuel ratio as a function of engine coolant temperature.
SECTION 307-
01: Automatic Transaxle/Transmission 2003 Mustang Workshop Manual Klj . 1 ba
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Ignition Coil —
Coil On Plug
The engine uses eight separate coil per plug units. Each coil per plug unit is controlled by the
powertrain control module (PCM).
Each coil per plug unit is mounted directly above each spark plug and activates its own spark plug in
the correct sequence as controlled by the PCM.
Refer to the Powertrain Control/Emissions Diagnosis (PC/ED) manual for additional information on the
ignition system.
Intake Air Temperature (IAT) Sensor
The intake air temperature (IAT) sensor provides the sequential fuel injection (SFI) system mixture
temperature information. The IAT sensor is used both as a density corrector for air flow calculation and
to proportion cold enrichment fuel flow. The IAT sensor is installed in the air cleaner inlet tube. The IAT
sensor is also used in determining EPC pressures.
Mass Air Flow (MAF) Sensor
The mass air flow (MAF) sensor measures the mass of air flowing into the engine. The MAF sensor
output signal is used by the powertrain control module to calculate injector pulse width. For
transmission strategies, the mass air flow sensor is used to regulate EPC, shift and torque converter
clutch scheduling.
Transmission Control Switch (TCS) and Transmission Control Indicator Lamp (TCIL)
The transmission control switch (TCS) is a momentary contact switch. When the switch is pressed, a
signal is sent to the PCM to allow automatic shifts from first through fourth gears or first through third
gears only. The PCM energizes the transmission control indicator lamp (TCIL) when the switch is off.
The TCIL indicates overdrive cancel mode activated (lamp on). When the TCIL is flashing, it indicates
electronic pressure control (EPC) circuit shorted or a monitored sensor failure.
Throttle Position (TP) Sensor
The throttle position (TP) sensor is a potentiometer mounted on the throttle body. The TP sensor
detects the position of the throttle plate and sends this information to the PCM. The TP sensor is used
for shift scheduling, electronic pressure control (EPC) and TCC control.
Digital Transmission Range (TR) Sensor
The digital transmission range (TR) sensor is located on the outside of the transmission at the manual
lever. The digital sensor completes the start circuit in PARK and NEUTRAL, and the back- up lamp
circuit in REVERSE. The digital sensor also opens/closes a set of four switches that are monitored by
the PCM to determine the position of the manual lever (P, R, N, D, 2, 1).
Output Shaft Speed (OSS) Sensor
The output shaft speed (OSS) sensor is a magnetic pickup, located at the output shaft ring gear, that
sends a signal to the powertrain control module (PCM) to indicate transmission output shaft speed.
The OSS sensor is used for torque converter clutch (TCC) control, shift scheduling and to determine
electronic pressure control (EPC).
Electronic Pressure Control (EPC) Solenoid
The EPC solenoid regulates transmission pressure. EPC valve pressure is used to control line
pressure.
Torque Converter Clutch (TCC) Solenoid Klj . 2 ba
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10. If the vehicle stalls in (D) or manual 2 at idle with vehicle at a stop, move the transmission range
selector lever to manual 1 position. If the vehicle stalls, see torque converter operation
concerns. For additional information, refer to Diagnosis By Symptom in this section. If the
vehicle does not stall in (D), refer to Diagnosis By Symptom in this section.
11. If the vehicle exhibits a vibration during the road test, complete the Road Test Evaluation Form. This form will aid the technician in determining the source of the vibration.
NOTE: The following is a list of common vehicle concerns that have been misdiagnosed as torque
converter clutch shudder. For diagnosis of the following items refer to the appropriate sections of the
workshop manual and the Powertrain Control/Emissions Diagnosis (PC/ED) manual.
zspark plugs - check for cracks, high resistance or broken insulators
z plug wires
z fuel injector - filter may be plugged
z fuel contamination - poor engine performance
z EGR valve - valve may let in too much exhaust gas and cause engine to run lean
z vacuum leak - engine will not get correct air/fuel mixture
z MAP/MAF sensor - incorrect air/fuel mixture
z HO2S sensor - too rich/lean air/fuel mixture
z fuel pressure - may be too low
z engine mounts - loose/damaged mounts can cause vibration concerns
z axle joints - check for vibration Torque Converter Road Evaluation Form
1) Does the Torque Converter
Engage/Disengage? Yes ·
GO to Step 2. No ·
REFER to Diagnosis By Symptom —
Torque Converter No Apply Routine
240/340 and Always Applied Routine
241/341 in this section for further
diagnosis information. Repair as
required, verify converter operation
and then continue. 2) Does vibration occur during 3-
4 or 4-3 shift at:
light, medium, or heavy throttle? Light ·
May be torque converter clutch
shudder. GO to Step 3. Medium ·
May be torque converter clutch
shudder. GO to Step 3. Heavy ·
Not torque converter clutch shudder
— converter does not engage due to
PCM strategy. REFER to Section 100 - 04 and
Diagnosis By Symptom —
Noise/Vibration Routine 254/354
in this section for further diagnosis. 3) Is the problem vehicle speed dependent Yes ·
Not torque converter clutch shudder Klj . 2 ba
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DIAGNOSIS AND TESTING
Diagnostic Trouble Code Charts
SECTION 307-
01: Automatic Transaxle/Transmission 2003 Mustang Workshop Manual Diagnostic Trouble Code Chart
Five
Digit
DTC Component Description Condition Symptom Action
P0102
P0103
P1100
P1101 MAF MAF concerns MAF system has a
malfunction which
may cause a
transmission
concern. High or low EPC
pressure, incorrect
shift schedule.
Incorrect torque
converter clutch
engagement
scheduling.
Symptoms similar
to a throttle position
(TP) failure. REFER to the
Powertrain
Control/Emissions
Diagnosis (PC/ED)
manual.
P0112 IAT IAT indicates
125°C (257°F)
(grounded) Voltage drop
across IAT
exceeds scale set
for temperature
125°C (257°F). Incorrect EPC
pressure, either
high or low, results
in harsh or soft
shifts. REFER to
thePowertrain
Control/Emissions
Diagnosis (PC/ED)
manual.
P0113 IAT IAT indicates -
40°C (-
40°F)
(open circuit) Voltage drop
across IAT
exceeds scale set
for temperature -
40°C (-
40°F). Incorrect EPC
pressure, either
high or low, results
in harsh or soft
shifts. REFER to the
Powertrain
Control/Emissions
Diagnosis (PC/ED)
manual.
P0114 IAT IAT out of on-
board
diagnostic
range IAT temperature
higher or lower
than expected
during KOEO and
KOER. Rerun on-
board
diagnostic at
normal operating
temperature. REFER to the
Powertrain
Control/Emissions
Diagnosis (PC/ED)
manual.
P0117 ECT ECT indicates
125°C (257°F) Voltage drop
across ECT
exceeds scale set
for temperature
125°C (257°F)
(grounded). Torque converter
clutch will always
be off, resulting in
reduced fuel
economy. REFER to the
Powertrain
Control/Emissions
Diagnosis (PC/ED)
manual.
P0118 ECT ECT indicates
-
40°C (- 40°F) Voltage drop
across ECT
exceeds scale set
for temperature -
40°C (-
40°F)
(open circuit). Torque converter
clutch will always
be off, resulting in
reduced fuel
economy. REFER to the
Powertrain
Control/Emissions
Diagnosis (PC/ED)
manual.
P0122
P0123
P1120 TP TP concern PCM has detected
an error that may
cause a
transmission
concern. Harsh
engagements, firm
shift feel, abnormal
shift schedule,
torque converter
clutch does not
engage, torque
converter clutch
cycling. REFER to the
Powertrain
Control/Emissions
Diagnosis (PC/ED)
manual.
P0300- Electronic EI systems EI system has a Harsh REFER to the Klj . 1 ba
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mechanism damaged
Main Controls
·
Manual valve stuck or
damaged ·
Inspect for damage. Repair as required. ·
Bolts not tightened to
specifications ·
Tighten bolts to specifications.
Other Concerns: External Leaks Possible Component Reference/Action
252 —
ELECTRICAL ROUTINE Powertrain Control System
·
Electrical inputs/outputs, sensor
seals leaking (digital TR, OSS,
vehicle speed sensor VSS, if
equipped, or transmission connector) ·
Inspect for leakage and repair as required. 352 —
HYDRAULIC/MECHANICAL ROUTINE Case
·
Case vent, case porosity, case
cracked ·
Check the vent for free breathing. Check the fluid level.
Check the transmission for overheat conditions. Repair
as required. Seals/Gaskets
·
Leakage at gaskets, seals, etc. (refer
to external sealing illustration for
potential leak locations) ·
Remove all traces of lubricant on exposed surfaces of
the transmission. Check the vent for free breathing.
Operate the transmission at normal temperatures and
perform fluid leakage check. Repair as required. Other
·
Cooler fitting, cooler lines pressure
tap, converter drain plug, band
anchor pins ·
Locate the source of the leak. Repair as required.
Other Concerns: Poor Vehicle Performance Possible Component Reference/Action
253 —
ELECTRICAL ROUTINE Powertrain Control System
·
Electrical inputs/outputs, vehicle
wiring harnesses, shift solenoids,
digital TR sensor, torque
converter clutch (TCC) solenoid,
transmission fluid temperature
(TFT) sensor ·
Carry out Self-Test. Refer to the Powertrain
Control/Emissions Diagnosis (PC/ED) manual for diagnosis
and testing of the Powertrain Control System. Go To Pinpoint Test A ,
Go To Pinpoint Test B or
Go To Pinpoint Test C . Repair as required. Clear codes, road test and
repeat Self- Test. Also refer to Routines 241/341 Torque
Converter Operation Concern: Always Applied. ·
Engine driveability concerns ·
Inspect air intake/air filter system. Check the fuel system
and fuel pressure. Refer to the Powertrain
Control/Emissions Diagnosis (PC/ED) manual. Inspect the
exhaust system for restriction. Refer to Section 309 - 00 .
353 —
HYDRAULIC/MECHANICAL ROUTINE Shift Linkage, Digital TR Sensor Klj . 27 ba
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SPECIFICATIONS
SECTION 310-
00: Fuel System — General Information 2003 Mustang Workshop Manual General Specifications
Item Specification
Fuel tank capacity 59.42 liters (15.7 gallons)
Key on, engine off fuel pressure 207-
345 kPa
(30-50 psi) Engine running fuel pressure (idle) 152-
255 kPa
(27-37 psi) Lubricants
SAE 5W-
20 Super Premium Synthetic Blend Motor Oil XO-5W20- QSP WSS-
M2C153- H Klj . 1 ba
12003 Mustang Workshop Manual
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GENERAL PROCEDURES
Pressure Relief
WARNING: Do not smoke or carry lighted tobacco or open flame of any type when
working on or near any fuel- related components. Highly flammable mixtures are always present
and may be ignited, resulting in possible personal injury.
WARNING: Fuel in the fuel system remains under high pressure even when the engine is
not running. Before servicing or disconnecting any of the fuel lines or fuel system components,
the fuel system pressure must be relieved to prevent accidental spraying of fuel, causing
personal injury or a fire hazard.
1. Remove the Schrader valve cap and install the Fuel Pressure Gauge.
2. CAUTION: Open the manual valve slowly on the Fuel Pressure Gauge.
Relieve the fuel pressure. zPlace the fuel in a suitable container.
SECTION 310-
00: Fuel System — General Information 2003 Mustang Workshop Manual Special Tool(s)
Fuel Pressure Gauge
310-
012 (T80L-9974- B) Klj . 1 ba
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GENERAL PROCEDURES
Spring Lock Couplings
Disconnect
WARNING: Do not smoke or carry lighted tobacco or open flame of any type when
working on or near any fuel- related components. Highly flammable mixtures are always present
and may be ignited, resulting in possible personal injury.
WARNING: Fuel in the fuel system remains under high pressure even when the engine is
not running. Before servicing or disconnecting any of the fuel lines or fuel system components,
the fuel system pressure must be relieved to prevent accidental spraying of fuel, causing
personal injury or a fire hazard.
1. Relieve the fuel system pressure. For additional information, refer to Pressure Relief in this
section.
2. Remove the fuel tube clip.
SECTION 310-
00: Fuel System — General Information 2003 Mustang Workshop Manual Special Tool(s)
Disconnect Tool, Spring Lock
Coupling (3/8 inch yellow)
310-
D004 (D87L-9280- A) or
equivalent Disconnect Tool, Spring Lock
Coupling (1/2 inch green)
310-
D005 (D87L-9280- B) or
equivalent
Material Item Specification
SAE 5W-
20 Super Premium
Synthetic Blend Motor Oil
XO- 5W20- QSP or equivalent WSS-
M2C153-
H Klj . 1 ba
32003 Mustang Workshop Manual
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GENERAL PROCEDURES
Fuel Line Fittings —
Push Connect
Disconnect WARNING: Do not smoke or carry lighted tobacco or open flame of any type when
working on or near any fuel- related components. Highly flammable mixtures are always present
and may be ignited, resulting in possible personal injury.
WARNING: Fuel in the fuel system remains under high pressure even when the engine is
not running. Before servicing or disconnecting any of the fuel lines or fuel system components,
the fuel system pressure must be relieved to prevent accidental spraying of fuel, causing
personal injury or a fire hazard.
1. Relieve the fuel system pressure. For additional information, refer to Pressure Relief in this
section.
2. Disconnect the safety clip from the male hose.
3. Install the Fuel Line Disconnect Set and push into the fitting.
SECTION 310-
00: Fuel System — General Information 2003 Mustang Workshop Manual Special Tool(s)
Disconnect Tool, Spring Lock
Coupling
310-
S039 (T90T-9550- S)
Material Item Specification
SAE 5W-
20 Super Premium
Blend Motor Oil
XO- 5W20-QSP or equivalent WSS-
M2C153-
H Klj . 1 ba
32003 Mustang Workshop Manual
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GENERAL PROCEDURES
Fittings
—R-Clip
Disconnect WARNING: Do not smoke or carry lighted tobacco or open flame of any type when
working on or near any fuel- related components. Highly flammable mixtures are always present
and may be ignited, resulting in possible personal injury.
WARNING: Fuel in the fuel system remains under high pressure even when the engine is
not running. Before servicing or disconnecting any of the fuel lines or fuel system components,
the fuel system pressure must be relieved to prevent accidental spraying of fuel, causing
possible personal injury or a fire hazard.
CAUTION: Do not use any tools. The use of tools may cause a deformity in the clip
components which may cause fuel leaks.
1. Relieve the fuel system pressure. For additional information, refer to Pressure Relief in this
section.
2. Remove the shipping tab by bending.
3. Spread the R- clip legs and push the clip into the fitting.
SECTION 310-
00: Fuel System — General Information 2003 Mustang Workshop Manual Material
Item Specification
SAE 5W-
20 Super Premium
Synthetic Blend Motor Oil
XO- 5W20- QSP or equivalent WSS-
M2C153-
H Klj . 1 ba
32003 Mustang Workshop Manual
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