check engine light FORD MUSTANG 2003 User Guide

Inspection and Verification
Certain axle noise or vibration symptoms are also common to the engine, transmission, wheel
bearings, tires, and other parts of the vehicle. For this reason, be sure that the cause of the trouble is
in the axle before disassembling, adjusting or repairing the axle. Refer to
Section 100 - 04 .
Certain driveshaft vibration symptoms are common to the front engine accessory drive (FEAD), the
engine, transmission or tires. Be sure the cause of the concern is the driveshaft before repairing or
installing a new driveshaft. Refer to Section 100 - 04 .
Certain symptoms may be caused by Traction- Lok® differentials (4026). Check the vehicle certification
label and axle identification tag to determine the type of differential. Refer to Section 100 - 01 .
Noise Acceptability
NOTE: A gear-driven unit will produce a certain amount of noise. Some noise is acceptable and
audible at certain speeds or under various driving conditions such as a newly paved blacktop road.
Slight noise is not detrimental to the operation of the axle and is considered normal.
With the Traction- Lok® differential axle, slight chatter noise on slow turns after extended highway
driving is considered acceptable and has no detrimental effect on the locking axle function.
Universal Joint (U- Joint) Inspection
Place the vehicle on a frame hoist and rotate the driveshaft (4602) by hand. Check for rough operation
or seized U- joints. Install a new U- joint if it shows signs of seizure, excessive wear, or incorrect
seating. Refer to Section 205 - 01 .
Analysis of Leakage
Clean up the leaking area enough to identify the exact source. An axle leak can be caused by the
following. zAxle lubricant level is too high.
z Worn or damaged axle shaft seals or differential seals.
z Differential housing is cracked.
z Flange yoke seat is worn or damaged.
z Pinion flange is scored or damaged.
z Axle cover is not sealed.
z Vent is plugged. Klj . 2 ba
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off the floor.
With the engine off, raise only one rear wheel. Install the special tool on the wheel nuts.
Use a torque wrench with a capacity of at least 271 Nm (200 lb-
ft) to rotate the axle shaft. Be sure that
the transmission is in NEUTRAL, and that one rear wheel is on the floor while the other rear wheel is
raised off the floor. The breakaway torque required to start rotation must be at least 27 Nm (20 lb- ft).
The initial breakaway torque may be higher than the continuous turning torque.
The axle shaft must turn with even pressure throughout the check without slipping or binding. If the
torque reading is less than specified, check the differential case. Refer to Section 205 - 02A or
Section 205 - 02B .
Traction- Lok® Differential Check Road Test
1. Place one wheel on a dry surface and the other wheel on ice, mud or snow.
2. Gradually open the throttle to obtain maximum traction prior to break away. The ability to move the vehicle demonstrates correct operation of a Traction- Lok® rear axle assembly.
3. When starting with one wheel on an excessively slippery surface, a slight application of the parking brake may be necessary to help energize the Traction- Lok® feature of the differential.
Release the brake when traction is established. Use light throttle on starting to provide
maximum traction.
4. If, with unequal traction, both wheels slip, the limited slip rear axle has done all it can possibly do.
5. In extreme cases of differences in traction, the wheel with the least traction may spin after the Traction-Lok® has transferred as much torque as possible to the non- slipping wheel. Klj . 15 ba
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PINPOINT TEST G: HYDRO-
BOOST BRAKE SYSTEM OPERATION
SUSPECT connections between the power steering pump reservoir and
between the power steering pump reservoir and the hydro-
boost
power brake booster.
z Are there any obstructions? REMOVE
obstructions or
INSTALL a new
hose.
No
GO to
F2 .
F2 CHECK BOOSTER OPERATION
z
Have an assistant check the fluid in the power steering pump
reservoir while rapidly applying the brake pedal approximately one
inch.
z Does the fluid show any movement or spouting? Yes
System OK.
No
INSTALL a new
hydro-boost
assembly. Test Step Result / Action to Take
G1 CHECK BASIC OPERATION
z
Key in OFF position.
z Press and release brake pedal several times to deplete all
hydraulic pressure from the hydro- boost power brake
booster.
z Press and hold brake pedal with light pressure.
z Key in START position.
z Does the brake pedal fall slightly and hold, and is less
pressure now required to hold brake pedal at the new
position? Yes
Hydro-
boost is OK.
No
GO to G2 .
G2 CHECK FOR HYDRAULIC BRAKE LEAK
z
With engine running, press and release brake pedal several
times.
z Hold brake pedal down with medium pressure, 34- 47 Nm
(25- 35 lb- ft).
z Does brake pedal move toward floor? Yes
GO to
G3 .
No
GO to G4 .
G3 CHECK FOR LEAKS —
BRAKE FLUID LINES z
Check for leaks at brake lines, including brake master
cylinder and brake hose.
z Do components check OK? Yes
COMPLETE master cylinder
By-
Pass Condition Test in
this section.
No
INSTALL new hoses and
lines as necessary. G4 CHECK HYDRO-
BOOST CONNECTIONS z
Clean the hydro- boost power brake booster, power steering
pressure hose, power steering gear pressure hose and
power steering return hose and connection.
z Start engine and run at idle.
z Check hose connections for leakage.
z Do hose connections check OK? Yes
GO to
G5 .
No
REPAIR or INSTALL new
hose and connections as
necessary. G5 CHECK FOR HYDRO-
BOOST LEAK Klj . 12 ba
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The function of the power brake booster check valve is to allow manifold vacuum to enter the power
brake booster and prevent the escape of vacuum in case manifold vacuum is lost during sustained full
throttle operation.
To test the function of the power brake booster check valve :
zStart and run the engine for at least 10 seconds.
z Operate the brake pedal to check for power assist.
z Disconnect the vacuum booster hose from the power brake booster check valve. Do not remove
the power brake booster check valve from the power brake booster.
z There should be enough vacuum retained in the brake booster for at least one more power-
assisted brake operation.
Brake Master Cylinder — Normal Conditions
The following conditions are considered normal and are not indications that the brake master cylinder
is in need of service.
Condition 1: During normal operation of the brake master cylinder, the fluid level in the brake master
cylinder reservoir will rise during brake application and fall during release. The net fluid level (i.e., after
brake application and release) will remain unchanged.
Condition 2: A trace of brake fluid will exist on the booster shell below the master cylinder mounting
flange. This results from the normal lubricating action of the master cylinder bore and seal.
Condition 3: Fluid level will decrease with pad wear.
Brake Master Cylinder — Abnormal Conditions
Changes in brake pedal feel or travel are indicators that something could be wrong in the brake
system. GO to Symptom Chart for abnormal condition diagnosis.
Bypass Condition Test 1. Disconnect the brake lines at the brake master cylinder.
2. Plug the outlet ports of the brake master cylinder.
3. Apply the brakes. If brake pedal height cannot be maintained, the brake master cylinder has an internal leak and must be rebuilt or replaced.
Compensator Port Check
The purpose of the compensator ports in the brake master cylinder is to supply any additional brake
fluid required by the system due to brake pad wear and to allow brake fluid returning from the brake
lines to the brake master cylinder to enter the brake master cylinder reservoir.
The returning brake fluid will cause a slight turbulence in the brake master cylinder reservoir. Klj . 14 ba
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11. Turn (or have an assistant turn) the steering wheel slightly in both directions and release quickly
while watching the pressure gauge.
zThe pressure reading should move from the normal back pressure reading and snap
back as the steering wheel is released.
z If the pressure returns slowly or sticks, the rotary valve in the steering gear is sticking or
the steering column is binding. Check the steering column and linkages before servicing
the steering gear.
Tie- Rod Articulation Torque
1. NOTE: This check may be done with the steering gear on or off the vehicle.
Disconnect the tie- rod end from the front wheel spindle. For additional information, refer to
Section 211 - 02 .
2. Move the front wheel spindle tie- rod back and forth three times.
3. Hook the special tool 211- 034 (T74P-3504-Y) over the tie-rod end or the threaded portion of the
front wheel spindle tie- rod and measure the force required to move the front wheel spindle tie-
rod. Refer to Tie- Rod Articulation Torque in General Specifications in this section.
4. If the force required to move the front wheel spindle tie- rod does not meet the specifications,
install a new front wheel spindle tie- rod. For additional information, refer to Section 211 - 02 .
Steering Gear Valve 1. With the vehicle in motion, place the transmission in NEUTRAL and turn the engine OFF. zIf the vehicle does not pull with the engine OFF, install a new steering gear. For
additional information, refer to Section 211 - 02 .
2. If the vehicle pulls with the engine OFF, cross- switch the front wheels.
3. If the vehicle pulls to the opposite side, cross- switch the front and rear wheels on the same side.
4. If the vehicle pull direction does not change, check the front suspension components, wheel alignment and frame alignment. For additional information, refer to Section 204 - 00 or frame
dimensions manual. Klj . 10 ba
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4. Inspect for normal burning.
zCheck for light tan or gray deposits on the firing tip.
5. Inspect for pre- ignition, identified by melted electrodes and a possibly damaged insulator.
Metallic deposits on the insulator indicate engine damage. This may be caused by incorrect
ignition timing, wrong type of fuel or the unauthorized installation of a heli- coil insert in place of
the spark plug threads.
zInstall a new spark plug.
6. Inspect for overheating, identified by a white or light gray spots and with bluish- burnt
appearance of electrodes. This is caused by engine overheating, wrong type of fuel, loose spark
plugs, spark plugs with an incorrect heat range, low fuel pump pressure or incorrect ignition
timing.
zInstall a new spark plug. Klj . 2 ba
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3.
NOTE: Running this test with the vehicle in gear or with the A/C compressor clutch engaged
(running) will cause incorrect diagnosis.
Place the transmission in PARK (P) or NEUTRAL (N).
4. Start the engine and allow the engine to idle throughout this test. Allow the engine to run for 2 minutes, then record the ECT (4.6L) or CHT (3.8L) voltage. Record the ECT (4.6L) or CHT
(3.8L) voltage every 60 seconds. When the ECT (4.6L) or CHT (3.8L) voltage trend changes
direction or only changes slightly (0.03 volts or less) from the previous reading, record this as
the thermostat opening voltage. Use the voltage and corresponding coolant temperature chart
listed below for 4.6L engines only.
5. If the thermostat opening voltage is greater than 0.75 volts and less than 82°C (180°F), install a new water thermostat.
6. If the thermostat opening voltage is less than 0.75 volts and greater than 82°C (180°F), the water thermostat is good and a new water thermostat should not be installed. GO to Symptom Chart for further instructions.
Thermostat — Mechanical Test
1. Remove the water thermostat.
2. Check the water thermostat for seating. Hold the water thermostat up to a lighted background. Leakage of light around the thermostat valve at room temperature indicates that a new water
thermostat should be installed. Some water thermostats have a small leakage notch at one
location on the perimeter of the thermostat valve, which is considered normal.
3. Immerse the water thermostat in a boiling coolant and water mixture.
4. See the General Specifications chart for water thermostat opening temperatures.
Radiator Leak Test, Removed From the Vehicle CAUTION: Never leak test an aluminum radiator in the same water that copper/brass
radiators are tested in. Flux and caustic cleaners may be present in the cleaning tank and they
will damage aluminum radiators.
NOTE: Always install plugs in the oil cooler fittings before leak- testing or cleaning any radiator.
NOTE: Clean the radiator before leak- testing to avoid contamination of tank. Coolant Temperature °C (°F) ECT (Volts)
22 (71) 3.00
43 (109) 2.01
71 (159) 1.01
82 (180) 0.75
91 (195) 0.059
97 (206) 0.050
105 (221) 0.040 Klj . 9 ba
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CAUTION: Some vehicle cooling systems are filled with Motorcraft Premium Engine
Coolant VC -4-A (in Oregon VC- 5, in Canada CXC- 10) or equivalent meeting Ford specification
ESE- M97B44- A (green color). Others are filled with Motorcraft Premium Gold Engine Coolant
VC -7-A or equivalent meeting Ford specification WSS- M97B51-A1 (yellow color). Always fill the
cooling system with the same coolant that is present in the system. Do not mix coolant types.
NOTE: The addition of Motorcraft Cooling System Stop Leak Pellets, VC- 6, darkens Motorcraft
Premium Gold Engine Coolant from yellow to golden tan.
1. Verify the customer's concern by operating the engine to duplicate the condition.
2. Inspect to determine if any of the following mechanical or electrical concerns apply.
3. If the inspection reveals an obvious concern that can be readily identified, repair it as necessary.
4. Inspect the coolant condition. 1. WARNING: Never remove the pressure relief cap while the engine is
operating or when the cooling system is hot. Failure to follow these instructions
can result in damage to the cooling system or engine or personal injury. To avoid
having scalding hot coolant or steam blow out of the degas bottle when removing
the pressure relief cap, wait until the engine has cooled, then wrap a thick cloth
around the pressure relief cap and turn it slowly. Step back while the pressure is
released from the cooling system. When you are sure all the pressure has been
released, (still with a cloth) turn and remove the pressure relief cap.
Allow the engine to cool. Once pressure is released, remove the pressure relief cap.
2. CAUTION: Check the coolant and engine oil level and top off the coolant if
needed. If there is engine coolant in the engine oil the cause must be corrected
and oil/fluid changed or major component damage can occur.
CAUTION: Some vehicle cooling systems are filled with Motorcraft Premium
Engine Coolant VC -4-A (in Oregon VC- 5, in Canada CXC- 10) or equivalent meeting
Ford specification ESE- M97B44-A (green color). Others are filled with Motorcraft
Premium Gold Engine Coolant VC -7-A or equivalent meeting Ford specification
WSS- M97B51- A1 (yellow color). Always fill the cooling system with the same
coolant that is present in the system. Do not mix coolant types.
Inspect the coolant color:
„If Motorcraft Premium Engine Coolant (green color) VC-4- A or equivalent meeting
Ford specification ESE-M97B44- A has a clear, light green or blue color, this Visual Inspection Chart
Mechanical Electrical
z
Radiator brackets
z Leaks
z Damaged hoses
z Hose clamps
z Water pump
z Radiator
z Degas bottle
z Water pump bracket z
Damaged water pump wiring Klj . 2 ba
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indicates higher water content than required.
„ NOTE: The addition of Motorcraft Cooling System Stop Leak Pellets, VC- 6,
darkens Motorcraft Premium Gold Engine Coolant from yellow to golden tan.
If Motorcraft Premium Gold Engine Coolant (yellow color) VC-7- A or equivalent
meeting Ford specification WSS- M97B51-A1 has a clear or pale yellow color, this
indicates higher water content than required.
„ Dark brown can indicate unauthorized stop leak may have been used. Use
Motorcraft Cooling System Stop Leak Pellets VC- 6 or equivalent meeting Ford
specification ESE-M99B37- 5 except as noted in ES-F65E-19A511- AA only.
„ A light or reddish brown color indicates that rust may be present in the cooling
system. Flush the system and refill with the correct mixture of water and engine
coolant.
„ An iridescent sheen on top of the coolant or a milky brown color can indicate a
trace of oil is entering the system. For additional information on engine diagnosis,
refer to Section 303 - 00 .
3. If the engine coolant appearance is acceptable, test the engine coolant freezing point
range with the special tool. The freezing point should be in the range - 50°F to -10°F. If
the vehicle is driven in cold climates less than - 34°F, it may be necessary to increase the
coolant concentration to get adequate freeze protection.
„Maximum coolant concentration is 60/40.
„ Minimum coolant concentration is 40/60.
4. Check the coolant system conditions:
„If the intercooler fluid is low, add the specified coolant mixture only.
„ If the intercooler coolant fluid tests weak, add straight engine coolant until the
readings are within acceptable levels.
„ If the engine coolant tests strong, remove some of the engine coolant and add
water until readings are within acceptable levels.
5. If the concern remains after the inspection, determine the symptom(s). GO to Symptom Chart .
6. Verify the cooling system is correctly filled and bled. Refer to Supercharger Cooling System Draining, Filling and Bleeding in this section.
Symptom Chart
Pinpoint Tests PINPOINT TEST A: LOSS OF COOLANT SYMPTOM CHART
Condition
Possible Sources Action
z Loss of intercooler
coolant z
Intercooler.
z Intercooler
radiator.
z Water pump.
z Coolant hoses.
z Degas bottle. z
Go To Pinpoint Test A . Klj . 3 ba
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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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