1988 PONTIAC FIERO transmission fluid

BRAKES 5-3
DIAGNOSIS AND INSPECTION
BRAKE SYSTEM TESTING
(Figures
2 through 4)
Brakes should be tested on dry, clean, reasonably
smooth and level roadway. A true test of brake performance
cannot be made if the roadway is wet, greasy or covered
with loose dirt so that all tires do not grip the road equally.
Testing will also be affected if the roadway is crowned
which would throw the weight of the car toward the wheels
on one side. If the roadway is too rough, the wheels will tend
to bounce. Test brakes at different car speeds with both light and
heavy pedal pressure, avoid locking the brakes and sliding
the tires. Locked brakes and sliding tires do not indicate
brake efficiency, because heavily braked, but turning
wheels will stop the car in less distance than locked brakes.
More tire-to-road friction is present with a heavily braked
turning tire than with a sliding tire. The brake system is designed and balanced to avoid
locking the wheels, except at very high deceleration levels.
The shortest stopping distance and best control is achieved
without brake lock-up.
Because of high deceleration capability, a firmer pedal
may be felt at higher deceleration levels.
External Conditions That Affect Brake Performance
1. Tires. Tires having unequal contact and grip on road
will cause unequal braking. Tires must be equally
inflated and tread pattern of right and left tires must
be approximately equal.
2. Car Loading. A heavily loaded car requires more
braking effort. When a car has unequal loading, the
most heavily loaded wheels require more braking
power than others.
3. Wheel Alignment. Misalignment of the wheels, par-
ticularly excessive camber and caster, will cause the
brakes to pull to one side.
4. Front Wheel Bearings. A loose front wheel bearing
BRAKE FLUID LEAKS
With engine running at idle and the transmission in neu-
tral, depress the brake pedal and hold a constant foot pres-
sure.
If the pedal gradually falls away with the constant
pressure, the hydraulic system may be leaking. Perform a
visual check to confirm any suspected leak.
Check the master cylinder fluid levels. While a slight drop
in reservoir level does result from normal lining wear, an
abnormally low level in either reservoir indicates
a leak in
the system. The hydraulic system may be leaking either
internally or externally. See "Master Cylinder Check."
Also, the system may appear to pass this test but still have
slight leakage.
If fluid levels are normal, check the vacuum booster
pushrod length. If an incorrect length pushrod is found,
adjust or replace the
pushrod. Check the service brake
pedal travel and the parking brake adjustment.
When checking the fluid levels, the master cylinder reser-
voir may be as low as
25 mm (1 inch) from the top if the front
linings are worn. This is not abnormal.
MASTER CYLINDER CHECK
These checks will help locate some master cylinder mal-
functions. Use the Brake Diagnosis Charts to help isolate
the problem if it is not found by using these tests.
1. Check for a cracked master cylinder casting or brake
fluid around the master cylinder. Leaks are indicated
only if there is at least a drop of fluid. A damp condi-
tion is not abnormal.
2. Check for a binding pedal linkage.
3. Disassemble the master cylinder and check for swol-
len or stretched piston
seal(s). If swollen seals are
found, substandard or contaminated brake fluid
should be suspected.
If contaminated, all compo-
nents should be disassembled and cleaned. All rub-
ber components should be replaced and all the pipes
should be flushed.
permits the front wheel to tilt and lose contact with the
SUBSTANDARD OR CONTAMINATED brake shoe linings causing erratic brake operation. BRAKE FLUID
WARNING LAMP OPERATION
The brake system uses a single red "BRAKE" warning
lamp located in the instrument panel cluster. When the
ignition switch is in the "START" position, the "BRAKE"
warning lamp should come on. It should go off when the
ignition switch returns to the "RUN" position.
The following conditions will activate the "BRAKE"
warning lamp:
1. Parking brake applied. The lamp should be on when
tfie parking brake is applied and the ignition switch is
"ON."
2. Pressure differential switch detects a failure. See
"Brake Pressure Differential Warning Switch" in this
section. Improper
brake fluid, mineral oil or water in the fluid may
cause the brake fluid to boil or the rubber components to
deteriorate.
If piston cups are swollen, the rubber parts have dete-
riorated. This deterioration may also be seen by swollen
wheel cylinder piston cups on the drum brake wheels or a
swollen master cylinder cover diaphragm.
If rubber deterioration is evident, disassemble all hydrau-
lic parts and wash with alcohol. Dry these parts with com-
pressed air before assembly to keep alcohol out of the
system. Replace all rubber parts in the system, including
hoses. Check for fluid on the linings. If excessive fluid is
found, replace the linings.
If master cylinder piston seals are satisfactory, check for
leakage or excessive heat conditions. If condition is not
found, drain fluid, flush with brake fluid, fill and bleed the
system.

ENGINE COOLING 6B-1
SECTION 6B
NE COOL
General Description ................................ 6B- 1 Off-Vehicle Leak Testing ............................... 6B-9
Radiator
...................................................... 6B- 1 Repairable Leaks ........................ ... .......... 6B- 10
Radiator Cap
......................... .. ............... 6B- 1 Repair Methods ................................................ 6B- 10
Recovery Bottle ......................................... 6B-2 Cooling Fin Removal ................................ 6B- 10 - ............................................. Fans ............................................................... 6B-2 Tube Blocking 6B- 1 1 ............ Header Repair ....................... .... 6B- 1 1 Temperature Switch ..................................... 6B-2 General Core Repair 6B- 1 1 ....................................
........................... Coolant Temperature Fan Switch ................ 6B-2 Tank
Gasket ~eik Repair 6B- 12
................... Thermostat .. 6B-3 Oil
Cooler Gasket Replacement
6B- 13 ............... ................................
...........................................................
Coolant Recovery System 6B-3 Recore 6B- 14 ............................. Special Tools ..................................................... 6B- 14 Diagnosis ..................................................... 6B-3
.............................. ..................................... Service Procedures 6B-3 On-Vehicle Service 6B-14
Cooling System Care
............................... 6B-3 Thermostat ....................................... 6B-14
Draining and Refilling the Cooling Electric Cooling Fan ............................. 6B-15
System
................................................... 6B-7 Water Pump .................... .... ......... 6B-15
Drive Belt
...................... .. .......................... 6B-7 Coolant Recovery Bottle ........................ 6B-16
.......................................... Aluminum Radiator Service .................... 6B-8 Radiator 6B-17
Diagnosis .................................................... 6B-8
Leak Testing
.............................................. 6B-8
On-Vehicle Pressure Testing
...................... .... 6B-9
GENERAL DESCRIPnIBN
The cooling system maintains engine temperature
5" below the filler neck which reads, "Important - for
at an efficient level during all engine operating repair see Harrison Service Manual". Service
conditions. When the engine is cold the system cools procedures for the aluminum plastic radiator are
slowly, or not at all, to allow the engine to warm up described in that manual and in this section.
quickly.
The cooling system includes a radiator and
Radiator Cap
recovery sub-system, cooling fan, thermostat and
housing, water pump, and drive belts.
Operation of the cooling system requires proper
functioning of all components. Coolant is drawn from
the radiator by the water pump and circulated through
water jackets in the engine block, intake manifold, and
cylinder
head(s), and then directed back to the radiator
where it's cooled.
This system directs some coolant through hoses
to the heater core, to provide for heating and
defrosting. A recovery bottle is connected to the
radiator to recover coolant displaced by expansion
from high temperatures and maintain correct coolant
level. As the coolant cools and contracts it is drawn
back into the radiator by vacuum.
RADIATOR
A cross-flow radiator is used on all models. Tanks
in this type radiator are located to the right and left of
the core, instead of above and below.
Radiators used with automatic transmissions
have oil coolers with inlet and outlet fittings for
transmission fluid circulation. Cars with manual
transmissions use radiators without oil coolers.
Vehicles equipped with air conditioning use a radiator
with extra cooling capability.
An aluminum-plastic radiator, used on some
models, can be identified by a note on the outlet tank A pressure-vent
cap is used on the cross-flow
radiator to allow a buildup of
103 kPa (15 psi) in the
cooling system. This pressure raises the boiling point
of coolant to approximately 125°C (262°F) at sea level.
Do not remove radiator cap to check engine
coolant level; check coolant visually at the
see-through coolant reservoir. Coolant should
be added only
to the reservoir.
CAUTION: As long as there
is
pressure in the cooling system, the
temperature can be considerably
higher than the boiling temperature
of
the solution in the radiator without
causing the solution to boil. Removal
of the radiator cap while engine is hot
and pressure is high will cause
the
solution to boil instantaneously and
possibly with explosive
force, spewing
the solution over engine, fenders and
person removing cap. If the solution
contains flammable antifreeze, such
as alcohol (not recommended for use
at any time), there is also the
possibility
of causing a serious fire.
The pressure-type radiator filler cap contains a
blow off or pressure valve and a vacuum or
atmospheric valve (Figure
1). The pressure valve is
held against its seat by a spring of pre-determined

ENGINE COOLING BB-7
NOTICE: If recommended quality antifreeze is
used, supplemental inhibitors or additives claiming
to provide increased cooling capability are not
necessary. They may be detrimental to the efficient
operation of the system, and represent an
unnecessary operating expense.
Every 12 months or 15,000 miles, the cooling
system should be serviced as follows;
1. Wash radiator cap and filler neck with clean
water.
2. Check coolant for proper level and freeze
protection.
3. Pressure test system and radiator cap for proper
pressure holding capacity, 103
kPa (15 psi). If
replacement of cap is required, use the proper cap
specified for car model.
4. Tighten hose clamps and inspect all hoses. Replace
hoses whenever cracked, swollen or otherwise
deteriorated.
5. Clean frontal area of radiator core and air
conditioning condenser.
DRAINING AND REFILLING THE COOLING
SYSTEM
Replace hoses every 24 months or 30,000 miles or
earlier if cracked, swollen or otherwise deteriorated.
Every two years or 30,000 miles, whichever first
occurs, the cooling system should be flushed and
refilled using the following recommended procedure:
1. Remove radiator cap, or thermostat housing cap
(VIN
0, J, R and U), when engine is cool by:
a. Slowly
rotating cap counterclockwise to
detent. (Do not press down while rotating.)
b. Wait until any
residual pressure (indicated
by a hissing sound) is relieved.
c. After all hissing ceases, press down on cap
while continuing to rotate
counterclockwise.
CAUTION: To avoid the danger of
being burned, do not remove radiator
cap while engine and radiator are still
hot. Scalding fluid and steam may be
blown out under pressure.
2. Remove the thermostat by using the wire handle
to lift it out of the housing (VIN
0, J, R and U).
3. With the thermostat removed, reinstall the
thermostat housing cap (VIN
0, J, R and U).
4. Open radiator drain valve and block drain plugs
to drain coolant. On VIN R and
9 (P series)
engines, open coolant pipe plugs.
5. Close valve. Reinstall drain plugs, and add
sufficient water to fill system.
6. Run engine, drain and refill the system, as
described in steps
4 and 5 a sufficient number of
times, until the drained liquid is nearly colorless.
Important
BLOCK DRIVE WHEELS, place
transmission in PARK (automatic
transmission) or NEUTRAL (manual
transmission) and set the parking brake. 7.
Allow system to drain completely. Then close
radiator drain valve tightly, and reinstall block
drain plugs.
8. Remove recovery cap leaving hoses in place.
Remove coolant recovery tank and empty of
fluid. Flush tank with clean water, drain and
reinstall.
9. Add sufficient ethylene glycol coolant, meeting
GM specification 1825-M, to provide the
required freezing and corrosion protection
- at
least 50 percent solution -37°C (-34°F). Fill
radiator to the base of the radiator fill neck and
add sufficient coolant to the recovery tank to
raise level to the "FULL" mark. Reinstall
recovery tank cap.
10. Run engine, with radiator cap or thermostat
housing cap removed, until normal operating
temperature is reached. (Radiator upper hose
becomes hot.)
11. With engine idling, add coolant until level
reaches bottom of filler neck and reinstall cap,
making certain arrows line up with overflow tube.
CAUTION: Under some conditions, the
ethylene glycol in engine coolant is
flammable. To help avoid being
burned when adding coolant, DO NOT
spill
it on the exhaust system or hat
engine parts.
It is the owner's responsibility to keep the freeze
protection at a level appropriate to the
temperatures which may occur in the area of
vehicle operation.
a. Maintain
cooling system freeze protection
at
-37°C (-34"F), to ensure protection
against corrosion and loss of coolant from
boiling, even though freezing temperatures
are not expected.
b. Add ethylene glycol base coolant that meets
GM Specification 1825-M, when coolant
additions are required because of coolant
loss, or to provide additional protection
against
freezing at temperatures lower than
-37°C (-34°F).
NOTICE: Alcohol or methanol base coolants, or
plain water, are not recommended at any time.
DRlVE BELT
NOTICE: Routine inspection of the belt may
reveal cracks in the belt ribs. These cracks will
not impair belt performance and therefore should
not be considered a problem requiring belt
replacement. However, the belt should be
replaced if belt slip occurs or if sections of the
belt ribs are missing.
A single (serpentine) belt is used to drive all
engine accessories formerly driven by multiple drive
belts. All belt driven accessories are ridgedly mounted
with belt tension maintained by a spring loaded
tensioner.
The drive belt tensioner has the ability to control
belt tension over a fairly broad range of belt lengths.

68-8 ENGINE COOLING
However, there are limits to the tensioner's ability to
The tensioner has rovisions for a visual check to
compensate for varying lengths of belts. With the
ten- verify that it is in t e "operating range" (see Figures
sioner outside of its operating range, poor tension
608 and 609). R
control andlor damage to the tensioner may result.
ALUMINUM RADIATOR REPAIR
This radiator utilizes an aluminum core with
plastic side tanks. The core and side tanks can be
replaced separately and core repair is easily made with
the hot melt adhesive method. A transaxle oil cooler
is located in one of the side tanks. The oil cooler can
be replaced. The drain cock is located on the lower part
of one of the tanks. The drain cock is also serviceable.
Core
The core is made of aluminum and is of the
crossflow design. It utilizes large tubes that resist
plugging, and repairs to the tubes and core are easily
made using the hot melt adhesive method.
The core is attached to the tanks by clinched tabs
on the core that can be bent back if tank or core
replacement is required.
If the damage to a tube is too severe, a tube can
be blocked or plugged as explained in "Tube Blocking.
" No more than two tubes should ever be blocked on
a core. Also replace the core if more than three tabs are
broken on one side, or if two adjacent tabs are broken.
Tanks
The tanks are attached to the core by the use of
clinched tabs. The clinched tabs can be bent back if the
tanks need to be removed from the core. Bend the tabs
back only enough to remove the tank. Overbending
will weaken the tabs.
A high temperature rubber gasket is used to seal
the mating surface between the core and the tank. (See
Fig. 8). The gasket must be replaced any time a tank
is removed from the core.
Transaxle Oil Cooler
The transaxle oil cooler is located in one of the
radiator side tanks. The oil cooler can be replaced by
removing the tank from the core.
A leaking oil cooler gasket can be replaced
without removing the tank from the core.
Drain Cock
The aluminum/plastic radiator utilizes a two
piece plastic drain cock and a rubber seal. The drain
cock is serviceable (See Fig.
9).
ALUMINUM RADIATOR SERVICE
The aluminum-plastic radiator can be repaired at
the dealership. The following components are easily
replaced:
e Core
e Tanks and gaskets
o Oil coolers and gaskets
e Drain cock and gasket The
tanks cannot be repaired if broken or
cracked. The radiator core can be replaced and the new
core used with the original tanks and oil cooler.
Precautions
As with all cooling system service, take measures
to prevent personal injury and damage to the system.
CAUTION: To help avoid the danger of
being burned, do not remove the
radiator cap while the engine and
radiator are
still hot. Scalding fluid
and steam can be blown out under
pressure if the
cap is taken off too
soon.
NOTICE: DO NOT USE "BOIL OUT" TANKS
OR VATS. Common service methods may
actually destroy an aluminum radiator. Caustic or
lye cleaning solutions must NOT be used for
aluminum radiators.
e Do not open the hood if you can see, or hear,
steam or coolant escaping from the engine
compartment.
e Do not remove radiator cap if radiator feels
warm.
e Do not remove the radiator cap or coolant
recovery tank cap if the coolant in the recovery
tank looks like it is boiling.
Wear eye protection.
e Wear gloves to protect your hands against
excessive heat, or the effects of chemicals on your
skin.
o Prevent dirt and water from entering the
transmission oil cooler.
e Do not use boil-out tanks, or vats, or other tanks
that have been used for copper and brass
radiators. The flux, acid, and caustic cleaners
remaining in these tanks will attack the
aluminum and cause radiator failure.
A separate
test tank containing clean water is strongly
recommended for servicing aluminum-plastic
radiators.
RIOTICE: Never use shop air that is not regulated
at
20 psi (138 kPa) to pressure test radiator.
Pressures over
20 psi (138 kPa) will damage the
radiator.
DIAGNOSIS
Leak Testing
Some core leaks can be detected by merely adding
water to the radiator. It is helpful to clean the core so
that the damaged area can be more easily found.

ENGINE COOLING 68.17
RADIATOR
Remove or Disconnect
1. Negative battery cable.
2. Engine coolant.
3. Fan blade. On fan clutch equipped cars, store
clutch in upright position to prevent seal leakage.
4. Upper and lower radiator hoses.
5. On vehicles equipped with automatic
transmission, plug transmission cooler lines.
6. Fan shield assembly, if applicable.
7. Radiator and shroud assembly, lift straight up.
The radiator assembly is held at the bottom by
two cradles secured to the radiator support.
Install or Connect
1. If new radiator, transfer fittings from old radiator
to new radiator.
Radiator in car, locating bottom of radiator in
lower mounting pads.
Transmission/Engine oil cooler lines at radiator.
Coolant recovery bottle hose at radiator.
Coolant hoses at radiator.
6. Upper radiator support bracket.
7. Engine coolant.
8. Negative battery cable.
Inspect -
e For proper completion of repair.
e For fluid leaks.

6D1-4 BATTERY
VOLTAGE
A. 16.0 or more
B. 14.0
- 15.9
C. 13.9 or less HOURS
1. Set parking brake and place automatic
Up to 4 Hours transmission in "PARK" (NEUTRAL for
Up to 8 Hours manual transmission.) Turn off the ignition,
Up to 16 Hours turn off lights, and all other electrical
If the charge current is still not
measurable
at the end of the above charging
times, the battery should be replaced.
If the charge current is measurable during
the charging time, the battery is considered to be
good and charging should be completed in the
normal manner.
5. It
is important to remember that a completely
discharged battery must be recharged for a
sufficient number of ampere hours (AH) to
restore it to a usable state. As a general rule of
thumb, using the reserve capacity rating (RC) of
the battery as the number of ampere hours of
charge will usually bring the green dot into view.
For example, if battery is rated at 75 RC minutes,
it would be completely recharged as follows:
10 ampere charge x 7-1/2 hours
= 75 AH
25 ampere charge x 3 hours = 75 AH, etc.
6. It
is recommended that any battery recharged by
this procedure be
LOAD TESTED to establish
serviceability.
JUMP STARTING IN CASE OF EMERGENCY
WITH AUXILIARY (BOOSTER) BAVEEWY
NOTICE: Do not push or tow the vehicle to start.
Damage to the emission system, or to other parts
of the vehicle may result.
Both booster and discharged battery should be
treated carefully when using jumper cables. Follow the
procedure outlined below, being careful not to cause
sparks:
CAUTION: Departure from these
conditions or the procedure below
could result in:
(1) Serious personal
injury (particularly to eyes) or property
damage from such causes as battery
explosion, battery acid, or electrical
burns; and/or
(2) damage to electronic
components of either vehicle.
Never expose battery to open flame or electric
spark
- batteries generate a gas which is flammable and
explosive.
Remove rings, watches, and other jewelry. Wear
approved eye protection.
Do not allow battery fluid to contact eyes, skin,
fabrics, or painted surfaces
- fluid is a corrosive acid.
Flush any contacted area with water immediately and
thoroughly. Be careful that metal tools or jumper
cables do not contact the positive battery terminal (or
metal in contact with it) and any other metal on the
car, because a short circuit could occur. Batteries
should always be kept out of the reach of children.
loads.
2. Check the built-in hydrometer. If it is clear or
light yellow, replace the battery.
3. Attach the end of one jumper cable to the positive
terminal of the booster battery and the other end
of the same cable to the positive terminal of the
discharged battery. Do not permit vehicles to
touch each other as this could cause a ground
connection and counteract the benefits of this
procedure. (Use 12-volt battery only to jump start
the engine).
4. Attach one end of the remaining negative cable
to the negative terminal of the booster battery,
and the other end to a solid engine ground (such
as
A/C compresser bracket or generator
mounting bracket) at least 18 inches from the
battery of the vehicle being started (DO NOT
CONNECT DIRECTLY TO THE NEGATIVE
TERMINAL OF THE DEAD BATTERY).
5. Start the engine of the vehicle that is providing
the jump start and turn off electrical accessories.
Then start the engine in the car with the
discharged battery.
6. Reverse these directions exactly when removing
the jumper cables. The negative cable must be
disconnected from the engine that was jump
started first.
I-FENDER 4-BATTERY (REF.)
2- BOLTISCREW 5-FENDER SKIRT
3-RETAINER
520028-60
Fig. 5 Battery Hold-Down (Typical)

DRIVEABILITY AND EMISSIONS - 5.OL (VIN El CEZ-C2-9
u PART IDENTIFICATION NUMBER
VENDOR IDENTlFlCATl
Figure C2-12 - Fuel Injector Part Number Location
Remove or Disconnect
lectrical connectors to fuel injectors. (Squeeze
plastic tabs and pull straight
up.)
2. Fuel meter
cover assembly following above
procedure.
3. With fuel meter cover gasket in place to prevent
damage to casting, use a screwdriver and fulcrum
to carefully lift out each injector (Figure
C2-11).
4. Lower (small) o-rings from nozzle of injectors and
discard.
5. Fuel meter cover gasket and discard.
6. Upper (large o-rings and steel backup washers
from top of each fuel injector cavity and discard.
Inspect
@ Fuel injector filter for evidence of dirt and
contamination.
If present, check for presence of
dirt in fuel lines and fuel tank.
Important
Be sure to replace the injector with an identical
part. Injectors from other models can fit in Model
220 TBI, but are calibrated for different flow rates.
(See Figure
C2-12 for part number location.)
Install or Connect
1. Lubricate new lower (small) o-ring with automatic
transmission fluid and push on nozzle end of
injector until it presses against
in,jector fuel filter.
2. Steel injector backup washer in counterbore of fuel
meter body.
3. Lubricate new upper (large) o-ring with automatic
transmission fluid and install directly over
the
backup washer. Be sure o-ring is seated properly
and is flush with top of fuel meter body surface.
I I 1 I FUEL INJECTOR ASSEMBLY
FUEL METER BODY ASSEMBLY
~p,~9~~~As
Figure C2-13 - Installing Fuel Injector
NOTICE: Backup washers and o-rings must be
installed before injectors, or improper
seating of large o-ring
could cause fuel
to leak.
4. Injector, aligning raised lug on each injector base
with notch in fuel meter body cavity. Push down
on injector until it is fully seated in fuel meter
body (Figure
C2-13). (Electrical terminals of
injector should be parallel with throttle shaft.)
5. Fuel meter cover gasket.
6. Fuel meter cover (see above procedure).
7. Fuel meter cover attaching screws, coated with
appropriate thread locking compound.
8. Electrical connectors to fuel injectors.
9. With engine "OFF" and ignition "ON", check for
fuel leaks.
FUEL METER BODY ASSEMBLY
Replacement (Figure
CZ-14)
a Remove or Disconnect
1. Electrical connections to fuel injectors. (Squeeze
plastic tabs and pull straight up.)
2. Fuel meter cover assembly, (see previous
procedure).
3. Fuel
meter cover assembly, following above
procedure.
4. Fuel injectors, following above procedure.
5. Fuel inlet and return lines. Discard o-rings.
6. Fuel inlet and outlet nuts and gaskets from the
fuel meter body assembly. Discard gaskets.
Important
Note locations of nuts, for proper reassembly
later. Inlet nut has a larger passage than
outlet nut.
7. Fuel meter body to throttle body attaching screw
assemblies.

DRIVEABILITY AND EMISSIONS - 5.0L (VIM E) 6E2-C8-1
SECTION C8
"FRANSMISSIBN CONVERnEW CLUTCH (TCC) SYSTEM
CONTENTS
GENERAL DESCRIPTION ............... C8-1 RESULTS OF INCORRECT TCC
PURPOSE
........................ C8-1 OPERATION ..................... C8-2
......................... OPERATION ...................... C8-1 DIAGNOSIS CS-2
.................... CIRCUIT DESCRIPTION ....e.e..eea..e C8-1 ON-CAR SERVICE C8-2
................. PARTS INFORMATION C8-2
GENERAL DESCRIPTION
PURPOSE
The transmission converter clutch (TCC) system
is designed to eliminate power loss by the converter
(slippage) thus increasing fuel economy. By locking
the converter clutch,
a more effective coupling to the
flywheel is achieved. The converter clutch is operated
by an ECM controlled solenoid.
OPERATION
Engagement of the TCC is accomplished by a
solenoid operated valve within the transmission. The
solenoid is activated when an internal switch in the
ECM is grounded. Although the ECM may command
the TCC
"ON", the converter clutch will not apply
until internal transmission fluid pressure require-
ments are met. See Section
"7A".
Before the ECM activates the TCC apply solenoid,
several inputs must be monitored:
e Vehicle Speed. Must be above a certain value
before the TCC can be applied.
Coolant Temperature. The engine coolant
temperature must be above a certain value
before the TCC can be applied.
@ Throttle Position Sensor. After the TCC is
applied, during low engine load condition, the
ECM uses the information from the TPS to
release the clutch when the car is accelerating
or decelerating at a certain rate.
CIRCUIT DESCRIPTION
When the brake pedal is not depressed (switch
closed), battery voltage will be fed to the TCC
solenoid. If the ECM has determined that conditions
are correct, the circuit from the TCC solenoid will be
completed to ground through the ECM and the TCC
solenoid will be activated.
Figure C8-1 - TCC Solenoid
Some transmission use other internal switches in
addition to the TCC solenoid.
@ 700-R4. transmissions normally use a 4th gear
switch to send
a signal to the ECM telling it
when the transmission is in
4th gear. The
ECM uses this information to vary the
conditions under which the clutch applies or
releases. However, the transmission does not
have to be in
4th gear in order for the ECM to
turn the clutch
"ON"
The 12 volt power supply for the solenoid in the
transmission is provided through
a normally closed
switch located on the brake pedal linkage. When the
brake pedal is depressed (switch open), the power
supply to the TCC solenoid is interrupted and the TCC
is disengaged regardless of any other conditions.