2003 FORD MUSTANG air condition

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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DIAGNOSIS AND TESTING
Diagnostic Strategy
Troubleshooting an electronically controlled automatic transmission is simplified by using the proven
method of diagnosis. One of the most important things to remember is that there is a definite
procedure to follow.
NOTE:
Do not take any short cuts or assume that critical checks or adjustments have already been
made.
Follow the procedures as written to avoid missing critical components or steps.
To properly diagnose a concern have the following publications available:
zTransmission Reference Manual.
z Powertrain Control/Emissions Diagnosis (PC/ED) manual.
z TSBs and OASIS Messages.
z Wiring Diagram.
These publications provide the information required when diagnosing transmission concerns.
Use the Diagnostic Flow Chart as a guide and follow the steps as indicated.
Preliminary Inspection
zKnow and understand the customer's concern.
z Verify the concern by operating the vehicle.
z Check the fluid levels and condition.
z Check for non-factory add- on items.
z Check shift linkages for proper adjustment.
z Check TSBs and OASIS messages regarding the concern.
Diagnostics
zCarry out on- board diagnostic procedures key on engine off (KOEO) and key on engine running
(KOER).
z Record all diagnostic trouble codes (DTCs).
z Repair all non- transmission codes first.
z Repair all transmission codes second.
z Erase all continuous codes and attempt to repeat them.
z Repair all continuous codes.
z If only pass codes are obtained, refer to Diagnosis By Symptom for further information and
diagnosis.
Follow the diagnostic sequence to diagnose and repair the concern the first time. SECTION 307-
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DIAGNOSIS AND TESTING
Diagnostic Flow Chart
SECTION 307-
01: Automatic Transaxle/Transmission 2003 Mustang Workshop Manual Diagnostic Flow Chart
z
Know and understand
the customer concerns
z Check the fluid level
and condition
z Verify the concern by
operating the vehicle
z Check for non- factory-
installed items and
verify correct installation
z Check the shift linkage
adjustments
z Check TSBs and
OASIS messages for
vehicle concerns
z Carry out quick test
both KOER and KOEO
z Record all codes
1) Did you record any
diagnostic trouble codes? Yes ·
REPAIR all hard diagnostic trouble codes. FOLLOW the
pinpoint tests. REFER to the Powertrain Control/Emissions
Diagnosis (PC/ED) manual first, then this Workshop Manual. No ·
REFER to Diagnosis By Symptom in this section, then GO to
Step 5. 2) Are any continuous test
memory codes present? Yes ·
CLEAR codes and CARRY OUT drive cycle test. No ·
GO to Step 4. 3) Did the continuous test
memory codes reappear? Yes ·
REPAIR all continuous test memory codes. FOLLOW the
pinpoint tests. REFER to the Powertrain Control/Emissions
Diagnosis (PC/ED) manual then the transmission reference
manual, then this workshop manual, then GO to Step 4. No ·
GO to Step 4. 4) Is the concern repaired? Yes ·
CARRY OUT the final quick test to verify that no diagnostic
trouble codes are present. CLEAR memory codes. No ·
REFER to Diagnosis By Symptom in this section.
5) Are there any electrical
concerns? Yes ·
INSTALL the scan tool and CARRY OUT the output state
control test, then GO to Step 6. No ·
REFER to the hydraulic and mechanical routine to diagnose
and REPAIR the concern, then GO to Step 7. 6) Was the transmission
concern corrected when the
scan tool was installed? Yes ·
REFER to the Powertrain Control/Emissions Diagnosis
(PC/ED) manual, intermittent fault diagnosis section and use
the scan tool to diagnose cause of concern in the processor,
vehicle harness or external inputs (sensors or switches). Klj . 1 ba
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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
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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DIAGNOSIS AND TESTING
Visual Inspection
This inspection will identify modifications or additions to the vehicle operating system that may affect
diagnosis. Inspect the vehicle for non-
Ford factory add-on devices such as:
z electronic add- on items:
„ air conditioning
„ generator (alternator)
„ engine turbo
„ cellular telephone
„ cruise control
„ CB radio
„ linear booster
„ backup alarm signal
„ computer
z Vehicle modification:
These items, if not installed correctly, will affect the powertrain control module (PCM), or transmission
function. Pay particular attention to add- on wiring splices in the PCM harness or transmission wiring
harness, abnormal tire size, or axle ratio changes.
zLeaks; refer to Leak Inspection.
z Correct linkage adjustments; refer to Section 307 - 05 .
Shift Linkage Check
Check for a misadjustment in shift linkage by matching the detents in the transmission range selector
lever with those of the manual lever in the transmission. If they match, the misadjustment is in the
indicator. Do not adjust the shift linkage.
Hydraulic leakage at the manual control valve can cause delay in engagements and/or slipping while
operating if the linkage is not correctly adjusted. Refer to Section 307 - 05 for shift linkage adjustment.
Check TSBs and OASIS
Refer to all technical service bulletins (TSB) and OASIS messages which pertain to the transmission
concern and follow the procedure as described.
Carry Out On- Board Diagnostics (KOEO, KOER)
After a road test, with the vehicle warm and before disconnecting any connectors, carry out the Quick
Test using the scan tool. Refer to the Powertrain Control/Emissions Diagnosis (PC/ED) manual. SECTION 307-
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DIAGNOSIS AND TESTING
Transmission Drive Cycle Test
NOTE:
Always drive the vehicle in a safe manner according to driving conditions and obey all traffic
laws.
NOTE: The Transmission Drive Cycle Test must be followed exactly. Malfunctions must occur four
times consecutively for shift error DTC code to be set, and five times consecutively for continuous TCC
code to set.
NOTE: When carrying out the Transmission Drive Cycle Test, refer to the Solenoid Application Chart
for correct solenoid operation.
After carrying out the Quick Test, use the Transmission Drive Cycle Test for checking continuous
codes.
1. Record and then erase Quick Test codes.
2. Warm engine to normal operating temperature.
3. Make sure transmission fluid level is correct.
4. With transmission in OVERDRIVE, moderately accelerate from stop to 80 km/h (50 mph). This allows the transmission to shift into fourth gear. Hold speed and throttle open steady for a
minimum of 15 seconds.
5. With transmission in fourth gear and maintaining steady speed and throttle opening, lightly apply and release brake to operate stoplamps. Then hold speed and throttle steady for a
minimum of five seconds.
6. Brake to a stop and remain stopped for a minimum of 20 seconds.
7. Repeat steps 4 through 6 at least five times.
8. Carry out Quick Test and record continuous DTCs. zIf the DTCs are still present, refer to the Diagnostic Trouble Code Chart. Repair all non
transmission DTCs first as they can directly affect the operation of the transmission.
Repeat the Quick Test and the Road Test to verify the correction. Erase the DTCs, carry
out the Drive Cycle Test and repeat the Quick Test after completing repair on the DTC.
z If the continuous test passes and a concern is still present, refer to Diagnosis By Symptom in this section, OASIS messages, and TSBs for concerns.
After On- Board Diagnostic
NOTE: The vehicle wiring harness, PCM and non- transmission sensors may affect transmission
operations. Repair these concerns first.
After the on- board diagnostic procedures are completed, repair all DTCs.
Begin with non- transmission related DTCs, then repair any transmission related DTCs. Use the
diagnostic trouble code chart for information on condition and symptoms. This chart will be helpful in
referring to the correct manual(s) and aids in diagnosing internal transmission concerns and external
non- transmission inputs. The pinpoint tests are used in diagnosing transmission electrical concerns.
Make sure that the vehicle wiring harness and the PCM are diagnosed as well. The Powertrain SECTION 307-
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Control/Emissions Diagnosis (PC/ED) manual will aid in diagnosing non-
transmission electronic
components.
Before Pinpoint Tests
NOTE: Prior to entering pinpoint tests, check the PCM wiring harness for tight connections, bent or
broken pins, corrosion, loose wires, correct routing, correct seals and their condition. Check the PCM,
sensors and actuators for damage. Refer to the Powertrain Control/Emissions Diagnosis (PC/ED)
manual.
NOTE: If a concern still exists after electrical diagnosis has been carried out, refer to Diagnosis By Symptom in this section.
If DTCs appear while carrying out the on- board diagnostics, refer to the Diagnostic Trouble Code Charts for the appropriate repair procedure. Prior to entering pinpoint tests, refer to any TSBs and
OASIS messages for transmission concerns. Klj . 2 ba
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