FORD MUSTANG 2003 Workshop Manual

The reverse clutch couples the input shaft to the reverse sun gear, applied in reverse range only.
One-
Way Clutch— Planetary (Low)
The planetary (low) one- way clutch is a roller clutch that holds the planetary gearset in first gear, (D)
and D ranges. During automatic coasting downshifts into first gear ((D) and D ranges), the planetary
one- way clutch freewheels so there is no engine braking.
One- Way Clutch— Intermediate 2 7B442 Reverse clutch plate external splined (steel)
3 7B066 Reverse clutch pressure plate (rear)
4 7D483 Reverse clutch pressure plate retaining ring
(select fit)
5 7F207 Forward clutch cylinder and input shaft assembly
6 7A019 Reverse clutch sun gear assembly
7 7B164 Reverse clutch plate internal splined (friction)
Item Part
Number Description
1 7A130 Planetary gear support assembly
2 7A089 Planetary one-
way clutch cage and spring roller
assembly 3 7A398 Planetary assembly
Item Part Number Description
1 391267-
S Retaining ring
2 7A089 Intermediate one-
way clutch assembly 3 7D044 Reverse clutch drum assembly Klj . 4 ba
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The intermediate one-
way clutch works with the intermediate friction clutch to hold the reverse clutch
drum and reverse sun gear stationary in second gear during acceleration. The intermediate one- way
clutch freewheels in third gear and during coasting in second gear, (D) and D ranges. Klj . 5 ba
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DESCRIPTION AND OPERATION
Hydraulic System
Fluid Pump
SECTION 307-
01: Automatic Transaxle/Transmission 2003 Mustang Workshop Manual Item Part Number Description
1 7A106 Front pump body assembly
2 7005 Case assembly
3 7A194 Transmission pan
4 7A191 Transmission pan gasket
5 7A098 Fluid filter and seal assembly
6 7A100 Main control assembly
7 7A108 Front pump support assembly
8 7D273 Fluid tube connector assembly (2 req'd)
Item Part Number Description Klj . 1 ba
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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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The transmission uses two accumulators:
z1-2 Accumulator — The 1-2 accumulator is used to soften the 1- 2 shift by absorbing some of
the pressure directed to the intermediate clutch. Constant line pressure is applied to the middle
section of the 1- 2 accumulator piston, opposing the intermediate clutch pressure, until the
pressure is high enough to overcome line pressure. The top of the piston is exhausted to the
sump.
z 2-3 Accumulator — The 2-3 accumulator is used to soften the 2- 3 shift by absorbing some of
the direct clutch pressure. Forward clutch pressure is applied to the top side of the 2- 3
accumulator piston, holding the piston down until clutch pressure is high enough to overcome it.
The middle section of the piston is exhausted to the sump. Item Part
Number Description
1 7F284 Spring — 1-
2 shift accumulator (model
dependent) 2 7F251 Piston — 1-
2 shift accumulator 3 7F284 Spring — 1-
2 shift accumulator (model
dependent) 4 7H300 Cover and seal assembly — 1-
2 accumulator 5 7384 Ring
— 2-1/16 retaining type HU internal 6 7B264 Retainer
— 2-3 shift accumulator piston 7 7F285 Spring — 2-
3 shift accumulator piston 8 7H292 Piston — 2-
3 shift accumulator Klj . 3 ba
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Klj . 4 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.
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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The TCC solenoid is used to control the apply and release of the TCC.
Shift Solenoid —
SSA, SSB
Two on/off shift solenoids provide gear selection of first through fourth gears by controlling the
pressure to the three shift valves. One unit containing the two shift solenoids is located in the main
control valve body. The shift solenoids are two- way, normally open style.
a When a manual pull- in occurs above a calibrated speed, the transmission will not downshift from the
higher gear until the vehicle speed drops below this calibrated speed.
EC = Electronically Controlled
HD = Hydraulically Disabled
Transmission Fluid Temperature (TFT) Sensor
The transmission fluid temperature (TFT) sensor is located on the lead frame assembly near the shift
solenoids on the main control valve body. It is a temperature- sensitive device called a thermistor. It
sends a voltage signal to the PCM. The voltage signal varies with transmission fluid temperature. The
PCM uses this signal to determine whether a cold start shift schedule is necessary. The shift schedule
is compensated when the transmission fluid temperature is cold. The PCM also inhibits (TCC)
operation at low transmission fluid temperatures and corrects electronic pressure control.
Vehicle Speed (VSS) Sensor
The source of vehicle speed (VSS) is model dependent. Possible sources of vehicle speed input are
anti- lock brake sensor (ABS), a gear- driven vehicle speed sensor (VSS), or an output shaft speed
sensor (OSS). The VSS signal is either an A/C signal whose frequency changes with speed, or an
SCP data message depending on the source. Some applications will have both. The vehicle speed
signal is an input to various vehicle subsystems such as the powertrain control module (PCM),
instrument cluster (speedometer and odometer), speed control system, etc. The vehicle speed source
must be operational to enter output state control (OSC) mode for diagnostics.
Regardless of the type of vehicle speed system, the PCM always uses the OSS for transmission and Solenoid Operation Chart Selector Lever Position PCM Commanded Gear Solenoids
SSA SSB TCC
P/R/N 1 ON OFF HD
(D) 1 ON OFF HD
(D) 2 OFF OFF EC
(D) 3 OFF ON EC
(D) 4 ON ON EC
w/OD OFF
1 1 ON OFF HD
2 2 OFF OFF EC
3 3 OFF ON EC
Manual 2 2 OFF OFF EC
Manual 1 1 ON OFF HD
1
a 2 OFF OFF EC Klj . 3 ba
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engine control. Klj . 4 ba
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