torque FORD MUSTANG 2003 Workshop Manual

The transmission uses a gerotor-
type design front pump support and gear. The pump provides the
volume of fluid needed to charge the torque converter, main control assembly, cooling system and
lube system. Pump pressure is regulated by the main regulator valve. The pump has an internal boost
circuit which is more efficient at lower engine speeds.
Filter
All fluid drawn from the transmission pan by the pump passes through the filter. The filter and its
accompanying seal are part of the fluid path from the sump (pan) to the fluid pump.
Main Control
The main control valve body houses three electronic solenoids:
ztwo shift solenoids
z one torque converter clutch solenoid (TCC solenoid) Accumulators 1 — Outer rotor (part of 7A103)
2 — Inner rotor (part of 7A103)
3 — Outlet
4 — Inlet
Item Part Number Description
1 — Shift solenoid A (part of 7G484)
2 7G136 Torque converter clutch solenoid
3 — Shift solenoid B (part of 7G484) Klj . 2 ba
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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.
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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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DIAGNOSIS AND TESTING
Preliminary Inspection
The following items must be checked prior to beginning the diagnostic procedures:
Know and Understand the Concern
In order to correctly diagnose a concern, first understand the customer complaint or condition.
Customer contact may be required in order to begin to verify the concern. Understand the conditions,
including when the concern occurs. For example:
zHot or cold vehicle temperature
z Hot or cold ambient temperature
z Vehicle driving conditions
z Vehicle loaded/unloaded
After understanding when and how the concern occurs, proceed to Verification of Condition.
Verification of Condition
This section provides information that must be used in both determining the actual cause of customer
concerns and carrying out the appropriate procedures.
The following procedures must be used when verifying customer concerns for the transmission.
Determine Customer Concern
NOTE: Some transmission conditions can cause engine concerns. An electronic pressure control short
circuit can cause engine misfiring. The torque converter clutch not disengaging will stall the engine.
Determine customer concerns relative to vehicle use and dependent driving conditions, paying
attention to the following items:
zHot or cold vehicle operating temperature
z Hot or cold ambient temperatures
z Type of terrain
z Vehicle loaded/unloaded
z City/highway driving
z Upshifting
z Downshift
z Coasting
z Engagement
z Noise/vibration — check for dependencies, either rpm dependent, vehicle speed dependent,
shift dependent, gear dependent, range dependent, or temperature dependent.
Check Fluid Level and Condition
Fluid Level Check SECTION 307-
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CAUTION: The use of any other type of transmission fluid than specified could result in
transmission failure.
If fluid needs to be added, add fluid in 0.25L (1/2 pint) increments through the filler tube. Do not overfill
the fluid. For fluid type, refer to the specification chart.
Fluid Condition Check
1. Check the fluid level.
2. Observe the color and the odor. The color under normal circumstances should be dark reddish, not brown or black or have a burnt odor.
3. Hold the fluid level indicator over a white facial tissue and allow the fluid to drip onto the facial tissue and examine the stain.
4. If evidence of solid material is found, the transmission fluid pan should be removed for further inspection.
5. If the stain is a foamy pink color this may indicate coolant in the transmission. The engine cooling system should also be inspected at this time.
6. If fluid contamination or transmission failure is confirmed by the sediment in the bottom of the fluid pan, the transmission must be disassembled and completely cleaned. This includes the
torque converter and cooler tubes. The oil- to-air cooler will need to be installed.
7. Carry out diagnostic checks and adjustments. Refer to Diagnosis By Symptom in this section. Klj . 3 ba
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DIAGNOSIS AND TESTING
Road Testing Vehicle
NOTE:
Always drive the vehicle in a safe manner according to the driving conditions and obey all
traffic laws.
The shift point road test and torque converter operation tests provide diagnostic information on
transmission shift controls and torque converter operation. SECTION 307-
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DIAGNOSIS AND TESTING
Shift Point Road Test
This test verifies that the shift control system is operating correctly.
1. Bring engine and transmission up to normal operating temperature.
2. Operate vehicle with transmission range selector lever in (D) position.
3. NOTE: Shift speed ranges are approximate for all applications. For specific applications
(engine, axle ratio and application) refer to the Automatic Transmission Specification Issue,
available from Ford Customer Service Division.
Apply minimum throttle and observe speeds at which upshift occurs and torque converter
engages; refer to the 4R70W Shift Speeds chart in this section.
4. With the transmission in Overdrive (fourth gear), press the transmission control switch. The transmission should downshift to third gear. Release the accelerator pedal; engine braking
should occur.
5. Press accelerator pedal to floor, wide open throttle (WOT). Transmission should shift from third to second gear, or third to first, depending on vehicle speed. Torque converter clutch should
disengage and then reapply.
6. With the transmission in (D) position and speed above 80 km/h (50 mph) and less than half throttle, move the transmission range selector lever from (D) position to manual 2 position and
remove pressure from the accelerator pedal. Transmission should immediately downshift into
second gear. With vehicle remaining in manual 2 position, move the transmission range selector
lever into manual 1 position, and release accelerator pedal. Transmission should downshift into
first gear at speeds approximately below 45- 56 km/h (28-35 mph).
7. If transmission fails to upshift/downshift or torque converter clutch does not apply and release, refer to Diagnosis By Symptom in this section.
SECTION 307-
01: Automatic Transaxle/Transmission 2003 Mustang Workshop Manual Shift Speeds 4.6L 4V MACH 1 (3.55:1
Axle Ratio)
Throttle Position Shift MPH Km/H
Light throttle 1-
2 10-14 16-23
TP voltage 2-
3 18-22 29-35
1.25 volts 3-
4 34-37 55-60
Closed throttle 4-
3 22-25 35-40
3-2 12-16 19-26
2-1 11-7 18-11
Wide open throttle 1-
2 36-44 58-71
2-3 75-83 121-134
3-2 70 113
2-1 33 53
Shift Speeds 4.6L 2V HO (3:27:1 Axle Klj . 1 ba
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DIAGNOSIS AND TESTING
Torque Converter Diagnosis
Prior to the installation of a new or remanufactured torque converter, all diagnostic procedures must be
followed. This is to prevent the unnecessary installation of torque converters. Only after a complete
diagnostic evaluation can the decision be made to install a new or remanufactured torque converter.
Begin with the normal diagnostic procedures as follows:
1. Preliminary inspection.
2. Know and understand the customer's concern.
3. Verify the condition — carry out the torque converter operation test.
4. Carry out diagnostic procedures.
z Carry out on- board diagnostics; refer to Diagnostics.
„ Repair all non- transmission related DTCs first.
„ Repair all transmission DTCs.
„ Rerun on- board diagnostic to verify repair.
z Carry out Line Pressure Test. For additional information, refer to Special Testing Procedures in
this section.
z Carry out Stall Speed Test. For additional information, refer to Special Testing Procedures in
this section.
z Carry out Diagnostic Routines. For additional information, refer to Diagnosis By Symptom in this
section.
„Use the Diagnosis by Symptom Index to locate the appropriate routine that best
describes the symptom(s). The routine will list all possible components that may cause or
contribute to the symptom. Check each component listed; diagnose and repair as
required before changing the torque converter.
Torque Converter Operation Test
This test verifies that the torque converter clutch control system and the torque converter are operating
correctly. 5. Carry out Quick Test with scan tool. For additional information, refer to the Powertrain Control/Emissions Diagnosis (PC/ED) manual. Check for DTCs.
6. Connect a tachometer to the engine.
7. Bring the engine to normal operating temperature by driving the vehicle at highway speeds for approximately 15 minutes in (D) position.
8. After normal operating temperature is reached, maintain a constant vehicle speed of about 80 km/h (50 mph) and tap brake pedal with the left foot.
9. Engine rpm should increase when brake pedal is tapped, and decrease about five seconds after pedal is released. If this does not occur, see torque converter operation concerns. For additional
information, refer to Diagnosis By Symptom in this section.
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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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(operating at steady speed, i.e. 64 km/h (40 mph)
regardless of transmission range. Verify by
manually selecting 2nd, OD cancel, and OD. —
REFER to Section 100 - 04 and
Diagnosis By Symptom —
Noise/Vibration Routine 254/354 in
this section for further diagnosis. No ·
GO to Step 4. 4) Is the problem engine-
rpm dependent?
(Occurs at the same engine rpm independent of
transmission gear. Verify by holding same rpm in
each transmission gear.) Yes ·
Not torque converter clutch shudder
— REFER to Section 100 - 04 and
Diagnosis By Symptom —
Noise/Vibration Routine 254/354 in
this section for further diagnosis. No ·
GO to Step 5. 5) Does the problem occur in coast, steady
speed, or reverse range? Yes ·
Not torque converter clutch shudder
— REFER to Section 100 - 04 and
Diagnosis By Symptom —
Noise/Vibration Routine 254/354 in
this section for further diagnosis. No ·
GO to Step 6. 6) Does vibration occur during extended light
brake application? Yes ·
Not torque converter clutch shudder
— REFER to Section 100 - 04 ,
Section 206 - 00 and
Diagnosis By Symptom —
Noise/Vibration Routine
254/354 in this section for further
diagnosis. No ·
GO to Step 7. 7) If one of the driving modes in Step 2 identifies
a vibration which was not present in Steps 3-
6,
then there is a strong possibility that the vibration
is caused by the torque converter clutch function.
Carry out the repair procedures as found under
Disassembly/Assembly. Klj . 3 ba
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