engine FORD MUSTANG 2003 Workshop Manual

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
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 vehicle should not be driven if the fluid level indicator shows the fluid
below the DO NOT DRIVE mark or internal failure could result.
NOTE: If the vehicle has been operated for an extended period, at high highway speeds, in city traffic,
during hot weather, or while pulling a trailer, the fluid needs to cool down to obtain an accurate
reading.
NOTE: The fluid level reading on the indicator will differ from operating and ambient temperatures. The
correct reading should be within the normal operating temperature range.
Under normal circumstances the fluid level should be checked during normal maintenance. If the
transmission starts to slip, shifts slowly, or shows signs of fluid leaking, the fluid level should be
checked.
1. With the transmission in P (PARK), the engine at idle, foot pressed on the brake, move the range selector lever through each gear and allow engagement of each gear. Place the
transmission range selector lever in the P position.
2. Wipe the fluid level indicator cap and remove the indicator.
3. Wipe the indicator with a clean cloth.
4. Install the indicator back in the filler tube until it is fully seated, then remove the indicator. The fluid level should be within the normal operating temperature range.
High Fluid Level
A fluid level that is too high may cause the fluid to become aerated due to the churning action of the
rotating internal parts. This will cause erratic control pressure, foaming, loss of fluid from the vent tube,
and possible transmission failure. If an overfill reading is indicated, drain and refill the transmission.
Low Fluid Level
A low fluid level could result in poor transmission engagement, slipping, or failure. This could also
indicate a leak in one of the transmission seals or gaskets. Adding Fluid Item Description
1 Fluid level at room temperature 10°-
35°C (50°-95°F) 2 Fluid level at operating temperature 66°-
77°C (150°-170°F) 3 Do not drive mark Klj . 2 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
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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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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Diagnosing an electronically controlled automatic transmission is simplified by using the following
procedures. One of the most important things to remember is that there is a definite procedure to
follow. DO NOT TAKE 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. By following the diagnostic sequence, the technician will be able to diagnose and repair the
concern the first time.
On-
Board Diagnostics With Diagnostic Tool
NOTE: For detailed instruction and other diagnostic methods using the scan tool, refer to the scan tool
tester manual and the Powertrain Control/Emissions Diagnosis (PC/ED) manual. These quick tests
should be used to diagnose the powertrain control module (PCM) and should be carried out in order.
zQuick Test 1.0 - Visual Inspection
z Quick Test 2.0 - Set Up
z Quick Test 3.0 - Key On, Engine Off (KOEO)
z Quick Test 4.0 - Continuous Memory
z Quick Test 5.0 - Key On, Engine Running (KOER)
„ Special Test Mode
„ Wiggle Test
„ Output Test Mode
„ PCM Reset Mode
„ Clearing DTCs
„ OBD II Drive Cycle
z Other Scan Tool Features
For further information on other diagnostic testing features using the scan tool, refer to the Powertrain
Control/Emissions Diagnosis (PC/ED) manual. Other diagnostic methods include the following:
„Parameter Identification (PID) Access Mode
„ Freeze Frame Data Access Mode and Manual
007-
00131 or equivalent 73 III Automotive Meter
105-
R0057 or equivalent UV Leak Detector Kit
164-
R0756 or equivalent Klj . 2 ba
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