Ford Thunderbird (2004 year). Manual — part 45

Do not make any unauthorized changes to your vehicle or engine. By
law, vehicle owners and anyone who manufactures, repairs, services,
sells, leases, trades vehicles, or supervises a fleet of vehicles are not
permitted to intentionally remove an emission control device or prevent
it from working. Information about your vehicle’s emission system is on
the Vehicle Emission Control Information Decal located on or near the
engine. This decal identifies engine displacement and gives some tune up
specifications.

On board diagnostics (OBD-II)

Your vehicle is equipped with a computer that monitors the engine’s
emission control system. This system is commonly known as the On
Board Diagnostics System (OBD-II). This OBD-II system protects the
environment by ensuring that your vehicle continues to meet
government emission standards. The OBD-II system also assists the
service technician in properly servicing your vehicle. When the Check
Engine/Service Engine Soon light illuminates, the OBD-II system has
detected a malfunction. Temporary malfunctions may cause your Check
Engine/Service Engine Soon light to illuminate. Examples are:

1. The vehicle has run out of fuel. (The engine may misfire or run
poorly.)

2. Poor fuel quality or water in the fuel.

3. The fuel cap may not have been securely tightened.

These temporary malfunctions can be corrected by filling the fuel tank
with good quality fuel and/or properly tightening the fuel cap. After three
driving cycles without these or any other temporary malfunctions
present, the Check Engine/Service Engine Soon light should turn off.
(A driving cycle consists of a cold engine startup followed by mixed
city/highway driving.) No additional vehicle service is required.

If the Check Engine/Service Engine Soon light remains on, have your
vehicle serviced at the first available opportunity.

Readiness for Inspection/Maintenance (I/M) testing

In some localities, it may be a legal requirement to pass an I/M test of
the on-board diagnostics system. If your “Check Engine/Service Engine
Soon” light is on, refer to the description in the Warning lights and
chimes section of the Instrument cluster chapter. Your vehicle may not
pass the I/M test with the “Check Engine/Service Engine Soon” light on.

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184

If the vehicle’s powertrain system or its battery has just been serviced,
the on-board diagnostics system is reset to a “not ready for I/M test”
condition. To ready the on-board diagnostics system for I/M testing, a
minimum of 30 minutes of city and highway driving is necessary as
described below:
• First, at least 10 minutes of driving on an expressway or highway.
• Next, at least 20 minutes driving in stop-and-go, city-type traffic with

at least four idle periods.

Allow the vehicle to sit for at least eight hours without starting the
engine. Then, start the engine and complete the above driving cycle. The
engine must warm up to its normal operating temperature. Once started,
do not turn off the engine until the above driving cycle is complete.

POWER STEERING FLUID

Refer to the scheduled maintenance guide for the service interval
schedules. If adding fluid is necessary, use only MERCON

威 ATF.

1. Start the engine and let it run
until it reaches normal operating
temperature (the engine coolant
temperature gauge indicator will be
near the center of the normal area
between H and C).

2. While the engine idles, turn the
steering wheel left and right several
times.

3. Turn the engine off.

4. Check the fluid level in the
reservoir. It should be between the
MIN and MAX lines. Do not add
fluid if the level is in this range.

5. If the fluid is low, add fluid in
small amounts, continuously
checking the level until it reaches
the range between the MIN and
MAX lines. Be sure to put the cap
back on the reservoir.

MAX

MIN

MAX

MIN

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185

BRAKE FLUID RESERVOIR

The fluid level will drop slowly as
the brakes wear, and will rise when
the brake components are replaced.
Fluid levels between the “MIN” and
“MAX” lines are within the normal
operating range, there is no need to
add fluid. If the fluid levels are
outside of the normal operating range, the performance of your brake
system could be compromised, seek service from your dealer
immediately.

TRANSMISSION FLUID

Checking automatic transmission fluid

The 5R55S transmission does not have a transmission fluid dipstick.

Refer to your scheduled maintenance guide for scheduled intervals for
fluid checks and changes. Your transmission does not consume fluid.
However, the fluid level should be checked if the transmission is not
working properly, i.e., if the transmission slips or shifts slowly or if you
notice some sign of fluid leakage.

Transmission fluid should be checked and, if required, fluid
should be added by a qualified technician.

Before adding any fluid, make sure the correct type is used. Use only
MERCON

威 V automatic transmission fluid. The type of fluid used is

indicated on the transmission fluid pan, extension housing and also in
the Lubricant specifications section in this chapter.

Use of a non-approved automatic transmission fluid may cause
internal transmission component damage and void the warranty.

Do not use supplemental transmission fluid additives, treatments or
cleaning agents. The use of these materials may affect transmission
operation and result in damage to internal transmission components.

AIR FILTER MAINTENANCE

Refer to the scheduled maintenance guide for the appropriate intervals
for changing the air filter element.

When changing the air filter element, use only the Motorcraft air filter
element listed. Refer to Motorcraft Part Numbers.

Note: Do not start your engine with the air cleaner removed and do not
remove it while the engine is running.

MAX

MIN

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186

Changing the air filter element

1. Loosen the hose clamp on the
outlet tube at the air filter housing.

2. Release the two clamps that
secure the cover to the air filter
housing and place the cover aside.

3. Remove the air filter element
from the air filter housing.

4. Wipe the air filter housing and cover clean to remove any dirt or
debris and to ensure good sealing.

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187