2003 FORD MUSTANG engine coolant

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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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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Stall Speed Test
WARNING: Apply the parking brake firmly while carrying out each stall test.
CAUTION: Carry out line pressure test prior to carrying out stall test. If the line pressure is
low at stall, do not carry out stall test or further transmission damage will occur.
The stall speed test checks:
zthe torque converter clutch operation and installation.
z the holding ability of the forward clutch.
z the reverse clutch (the low- reverse bands).
z the planetary one- way clutch.
z the engine driveability.
Conduct this test with the engine coolant and transmission fluid at correct levels and at normal
operating temperature.
Apply the parking brake firmly for each stall speed test. 1. Find the specified stall rpm for the vehicle; see the stall speed diagnosis chart. Use a grease pencil to mark the rpm on the dial of a tachometer.
2. Connect a tachometer to the engine.
3. NOTE: If the rpm recorded by the tachometer exceeds the maximum limits, release the
accelerator pedal immediately because clutch or band slippage is indicated.
In each of the following ranges (D), 2, 1, R, press the accelerator pedal to the floor and hold it ·
Reverse Clutch Low In Neutral Only ·
Valve Body Low In Overdrive Only ·
Forward Clutch ·
Valve Body Low In 1st Position Only ·
Forward Clutch ·
Valve Body ·
Low/Reverse Servo Low In 2nd Only ·
Intermediate Clutch ·
Valve Bodies ·
Forward Clutch Stall Speed
Application Min. Max.
3.8L engine 2,240 2,619
4.6L 2V engine 2,339 2,738
4.6L 4V MACH 1 engine 2,375 2,767 Klj . 4 ba
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DIAGNOSIS AND TESTING
Leakage Inspection
CAUTION: Do not try to stop the fluid leak by increasing the torque beyond specifications.
This may cause damage to the case threads.
Check the fluid filler tube connection at the transmission case. If leakage is found here, install a new
grommet.
Check the VSS plug or VSS sensor O-ring (model dependent). If leakage is found install a new O- ring.
Check fluid lines and fittings between the transmission and the cooler in the radiator tank for
looseness, wear, or damage. If leakage cannot be stopped by tightening a fluid tube nut, install new
parts. When fluid is found leaking between the case and cooler line fitting, check for missing or
damaged O- ring, then tighten the fitting to maximum specification.
If the leak continues, install a new cooler line fitting and tighten to specification. The same procedure
should be followed for fluid leaks between the radiator cooler and the cooler line fittings in this section;
refer to Section 307 - 02 .
Check the engine coolant in the radiator. If transmission fluid is present in the coolant, the cooler in the
radiator is probably leaking.
The cooler can be further checked for leaks by disconnecting the lines for the cooler fittings and
applying no more than 345 kPa (50 psi) air pressure to the fittings. Remove the radiator cap to relieve
the pressure buildup at the exterior of the oil cooler tank. If the cooler is leaking and or will not hold
pressure, install a new cooler.
If leakage is found at the transmission range selector lever, install a new seal.
If leakage is found at the transmission internal harness connector, install a new O- ring. 4R70W External Sealing SECTION 307-
01: Automatic Transaxle/Transmission 2003 Mustang Workshop Manual Klj . 1 ba
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DESCRIPTION AND OPERATION
Transmission Cooling —
Integral
This vehicle with an automatic transmission is equipped with an integral transmission fluid cooler. The
cooler is contained inside of the radiator outlet tank and cannot be serviced separately. The cooler
transfers heat from the transmission fluid to the engine coolant.
For transmission fluid cooler flow test, refer to Section 307 - 01 .
For transmmission fluid cooler backflushing and cleaning, refer to Section 307 - 01 .
Transmission Fluid Cooler Tubes SECTION 307-
02: Transaxle/Transmission Cooling 2003 Mustang Workshop Manual Item Part Number Description
1 — Fluid cooler inlet tube
2 — Fluid cooler outlet tube
3 7005 Transmission case
4 — Transmission case fittings Klj . 1 ba
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DIAGNOSIS AND TESTING
Transmission Cooling
Inspection and Verification
WARNING: Never remove the radiator cap under any conditions while the engine is
operating. Failure to follow these instructions could result in personal injury and/or damage to
the cooling system or engine. To avoid having scalding hot coolant or steam blow out of the
radiator, use extreme care when removing the radiator cap from a hot radiator. Wait until the
engine has cooled, then wrap a thick cloth around the radiator cap and turn it slowly to the first
stop. Step back while the pressure is released from the cooling system. When you are certain
all the pressure has been released, press down on the radiator cap (with a cloth), turn and
remove.
The transmission fluid cooler is integral to the radiator (8005). Whenever leaks or damage to the
radiator are found, install an entire new radiator. For additional information, refer to Section 303 - 03A or
Section 303 - 03B .
Symptom Chart SECTION 307-
02: Transaxle/Transmission Cooling 2003 Mustang Workshop Manual SYMPTOM CHART
Condition
Possible Sources Action
z Transmission
Overheating z
Damaged radiator. zREPAIR or install a new
radiator. For additional
information, REFER to
Section 303 - 03A or
Section 303 - 03B .
z System leaks. zINSPECT for leaks. REPAIR
as necessary.
z Incorrect fluid level. zADJUST to proper level.
z Fluid condition. zINSPECT according to
instructions under Fluid
Condition Check. REFER to
Section 307 - 01 .
z Damaged, blocked,
reversed, leaking or
restricted cooler lines
or cooler tubes. z
INSPECT cooler lines and
tubes. REPAIR or flush as
necessary.
z Engine concerns
causing transmission
to overheat. z
INSPECT engine cooling
system. For additional
information, REFER to
Section 303 - 03A or
Section 303 - 03B .
z Excessive towing
loads. z
CHECK gross vehicle weight.
z Incorrect idle or
performance. z
REFER to the Powertrain
Control/Emissions Diagnosis
(PC/ED) manual. Klj . 1 ba
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Symptom Chart
Condition
Possible Sources Action
z Incorrect/erratic direction
of airflow from outlet(s) z
No vacuum to A/C heater
function switch selector.
z A/C heater function selector
switch leaks vacuum.
z Kinked/pinched vacuum hose.
z Leaking vacuum control
motor.
z Leaking A/C vacuum check
valve.
z Leaking A/C vacuum reservoir
tank and bracket.
z Vacuum actuator arm not
connected to door crank. z
Go To Pinpoint
Test A .
z Insufficient, erratic, or no
heat z
Low engine coolant level.
z Thermostat stuck open.
z Disengaged/damaged
temperature cable. z
Go To Pinpoint
Test B .
z The A/C does not
operate/does not operate
correctly z
CASS strategy failure.
z Open fuses.
z A/C clutch relay.
z Shorted blend door actuator.
z Powertrain control module.
z Circuitry short/open.
z A/C cycling switch damaged.
z A/C system discharged/low
charge.
z Function selector switch
damaged.
z A/C pressure cut-off switch
damaged.
z A/C compressor clutch
damaged. z
Go To Pinpoint
Test C .
z The A/C is always on zCircuitry short/open.
z A/C cycling switch.
z A/C heater function selector
switch.
z Constant control relay
module.
z Incorrect A/C clutch air gap. z
Go To Pinpoint
Test D .
z Insufficient A/C cooling zRestricted A/C evaporator
core orifice.
z Low refrigerant level. z
Go To Pinpoint
Test E .
z No operation in all the
temperature settings z
Damaged blend door actuator
cable.
z Damaged air temperature
control door. z
Go To Pinpoint
Test F .
z The blower motor does
not operate z
Open fuse.
z Circuitry open/shorted.
z Damaged heater blower
motor switch (18578).
z Damaged heater blower
motor switch resistor (18591).
z Damaged blower motor relay.
z Damaged blower motor. z
Go To Pinpoint
Test G .
z The blower motor
operates continuously in z
Circuitry short/open.
z Damaged heater blower z
Go To Pinpoint Klj . 6 ba
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PINPOINT TEST B: INSUFFICIENT, ERRATIC, OR NO HEAT z
Does the vacuum control motor hold a vacuum? A20 CHECK THE VACUUM CONTROL MOTOR INSTALLATION
z
Key in OFF position.
z Check the attachment of the vacuum control motor arm to
damper door.
z Is the vacuum control motor arm attached to the door or
door crank arm? Yes
REPAIR or INSTALL a
new damper door.
TEST the system for
normal operation.
No
CONNECT the vacuum
control motor arm to
the door and check
operation. TEST the
system for normal
operation.
Test Step Result / Action to Take
B1 CHECK FOR CORRECT ENGINE COOLANT LEVEL
z
Key in OFF position.
z Check the engine coolant level when hot and cold.
z Is the engine coolant at the correct level (hot/cold) as
indicated on the engine coolant recovery reservoir? Yes
GO to
B2 .
No
GO to B3 .
B2 CHECK FOR HOT WATER TO THE HEATER CORE INLET
HOSE WARNING: The heater core inlet hose will become
too hot to handle and may cause serious burns if the
system is working correctly.
z Key in START position.
z Allow the engine to reach normal operating temperature.
z Feel the heater core inlet hose. Yes
GO to
B4 .
No
TEST the engine cooling
system for correct
operation. REFER to
Section 303 - 03A or
Section 303 - 03B . Klj . 14 ba
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