engine FORD MUSTANG 2003 Workshop Manual

DESCRIPTION AND OPERATION
Range Selection
The transmission has six range positions: P, R, N, (D), 2 and 1.
Park
In the PARK position:
zthere is no powerflow through the transmission.
z the parking pawl locks the output shaft to the case.
z the engine can be started.
z the ignition key can be removed.
Reverse
In the REVERSE position:
zthe vehicle can be operated in a rearward direction, at a reduced gear ratio.
z engine braking will occur.
Neutral
In the NEUTRAL position:
zthere is no powerflow through the transmission.
z the output shaft is not held and is free to turn.
z the engine can be started.
Overdrive
Overdrive is the normal position for most forward driving.
The OVERDRIVE position provides:
zAutomatic shifts.
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z
Apply and release of the torque converter clutch.
z Maximum fuel economy during normal operation.
Second Position
This position provides:
zSecond gear start and hold.
z The torque converter clutch can apply and release.
z Improved traction and engine braking on slippery roads.
z Engine braking for descending steep grades.
First Position
If this position is selected at normal road speeds, the transmission will shift into second gear, then into
first when the vehicle reaches a speed below approximately 45 km/h (28 mph).
This position provides:
zFirst gear operation only.
z Engine braking for descending steep grades. Klj . 2 ba
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DESCRIPTION AND OPERATION
Shift Patterns
Upshifts
Transmission upshifting is controlled by the powertrain control module (PCM). The PCM receives
inputs from various engine or vehicle sensors and driver demands to control shift scheduling, shift feel
and torque converter clutch (TCC) operation.
Downshifts
Under certain conditions the transmission will downshift automatically to a lower gear range (without
moving the gearshift lever). There are three categories of automatic downshifts; Coastdown, Torque
Demand and Forced or Kickdown shifts.
Coastdown
The coastdown downshift occurs when the vehicle is coasting down to a stop.
Torque Demand
The torque demand downshift occurs (automatically) during part throttle acceleration when the
demand for torque is greater than the engine can provide at that gear ratio. If applied, the transmission
will disengage the TCC to provide added acceleration.
Kickdown
For maximum acceleration, the driver can force a downshift by pressing the accelerator pedal to the
floor. A forced downshift into a lower gear is possible below calibrated speeds. Specifications for
downshift speeds are subject to variations due to tire size, engine and transmission calibration
requirements.
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4 — Impeller (part of 7902)
5 — Fluid motion
6 — Transmission input rotation
7 — Input shaft
8 — Engine rotation Klj . 2 ba
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DESCRIPTION AND OPERATION
Apply Components
There are eight apply components used to drive or hold the planetary gearset components.
Band—
Overdrive
The overdrive band holds the reverse clutch drum stationary in fourth gear and manual 2. This action
causes the reverse sun gear to be held in these ranges.
Band— Low and Reverse
The low and reverse band holds the pinion carrier in reverse. The reverse band also applies in manual
1 position to provide engine braking.
Clutch— Intermediate Intermediate Clutch Disassembled View SECTION 307-
01: Automatic Transaxle/Transmission 2003 Mustang Workshop Manual Item Part Number Description
1 7F196 Overdrive band assembly
2 7D044 Reverse clutch drum assembly
Item Part Number Description
1 7A398 Planetary assembly
2 7D095 Reverse band assembly Klj . 1 ba
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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 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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engine control. Klj . 4 ba
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