1996 HONDA CIVIC ac clutch circuit

Description
Hydraulic Flow (cont'd)
lll Position
The flow of fluid through the torque converter circuit is the same as in E position. The line pressure (1) changes to theline pressure (3) and flows to the l-2 shift valve. The line pressure (3) changes to the line pressure (3,) at the 1-2 shift valveand flows to the servo valve. The servo valve is moved to the right side (Reverse range position) and uncovers the port toallow line pressure (3") to the manual valve as in @ position. The line pressure (3") from the servo valve is Intercepted bythe manual valve. However, hydraulic pressure is not supplied to the clutches, and the power is not transmitted.
NOTE: When used, "|eft" or "right" indicates direction on the hydraulic circuit.
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I
TOROUE CONVERTER
No Lock-up
. Lock-up Control Solenoid Valve A: OFF
. Lock-up Control Solenoid Valve B: OFF
. Linear Solenoid Pressure: High
The pressurized fluid regulated by the modulator works
on both ends of the lock-up shift valve. Under this condi-
tion, the pressures working on both ends of the lock-up
shift valve are equal, the lock-up shift valve is moved to
the right side by the tension of the valve spring alone.
The fluid from the ATF pump will flow through the left
side of the lock-up clutch to the torque convener; that is,
the lock-up clutch is in OFF condition.
NOTE: When used, "left" or "right" indicates direction
on the hydraulic circuit.
MOOULATOR PRESSURE
LINEAR SOLENOIO PRESSURE
(cont'd)
LOCK.UP CONTROLSOLENOID VALVE
RELIEF VALVE
LOCK-UP TIMINGVALVE
9 L ] I COOLER RELIEF VALVE
ATF PUMP
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Description
Lock-up System (cont'dl
TOROUE CONVERTER
Half Lock-up
. Lock-up Control Solenoid Valve A: ONLock-up Control Solenoid Valve 8: Duty Operation
OFF - ONLinear Solenoid Pressure: Low
The PCM switches the solenoid valve A on to release themodulator pressure in the left cavity of the lock_up shiftvalve. The modulator pressure in the right cavity of thelock-up shift valve overcomes the spring force; thus thelock-up shift valve is moved to the left side.The line pressure is then separated into the two pas-sages to the torque converter:
Torque Converter Inner pressure: enters into rightsade to engage lock-up clutch
Torque Converter Back pressure: enters into left sideto diseogage lock-up clutchThe back pressure (F2) is regulated by the lock-up con-trol valve, whereas the position of the lock-up timingvalve is determined by the linear solenoid Dressure andtension of the valve spring. Also the position of the lock_up control valve is determined by the back pressure ofthe lock-up control valve, torque converter pressure reg_ulated by the torque converter check valve, and modula_tor pressure determined by the lock-up control solenoidvalve B. The PCM switches the lock-up control solenoidvalve B on and off rapidly {duty operation} under certainconditions to regulate the back pressure (F2) to lock thetorque convener properly.
NOTE: When used, "left" or "right" indicates directionon the hvdraulic circuit.
MODULATOR PRESSURE
LINEAR SOLENOTD PRESSURE
LOCK.UP CONTROLVALVE
LOCK.UP CONTROLSOI.TNOID VALVE
A8
TOROUE CONVERTERCHECK VAI-VE
RELIEF VALVE
LOCK-UP TIMINGVALVE
^ L____J'r cooLER RELTEF valvE
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ATF PUMP

TOROUE CONVERTER
Full Lock-up
. Lock-up Control Solenoid Valve A: ON
. Lock-up Control Solenoid Valve B: ON
o Linear Solenoid Pressure: High
When the vehicle speed further increases. the linear
solenoid pressure is increased to high in accordance
with the linear solenoid controlled bv the PCM.
The lock-up timing valve overcomes the spring force
and moves to the left side. Also, this valve closes the
fluid port leading to the left side of the lock-up control
Under this condition. the modulator pressure in the left
side of the lock-up control valve had already been
released by the lock-up control solenoid valve B; the
lock-up control valve js moved to the left side. As this
takes place, the torque converter back pressure is
released fully. causing the lock-up clutch to be engaged
fully.
NOTE: When used, "|eft" or "right" indicates direction
on the hvdraulic circuit.
MODULATOR PRESSURE
LINEAR SOLENOIO PRESSURE
{cont'd)
LOCK.UP CONTROLSOLENOID VALVE
RELIEF VALVE
LOCK.UP TIMINGVALVE
'r ,-.r' cooLER RELTEF vALvE
ATF PUMP
14-37

Continuously Variable Transmission (CVTI
Special Tools ................ 14-194
Description .................... 14-195
Clutches/Reverse Brake/Planetary
Gear/Pulleys .......... 14-198
power Flow ..............,..... 14-200
Electronic Control SYstem(,96 - 98 Modets) ......14-203
Electronic Control System
('99 - oo Models) " 14-205
Hydraulic Control '....... 14-208
Hydraulic Flow .'..-.....'... '14-212
Park Mechanism .....-...'.' 14-222
Eleqtrical Systom
Component Locations'96 - 98 Models """"""' 14-224,99 - 00 Modets ............. 14-225
TCM Circuit Diagram ('96 - 98 Models) ............. 14-226
TCM Terminal Voltage/Measuring Condiiions ('96 - 98 Models) '.... 14-228
PcM Circuit Oiaqram{A/T Control System: '99 - 00 Models} ...--.... 14-230
PCM Terminal Voltage/Measuring Conditions('99 - 00 Models)
A/4 Control System .'.'...14-232
Troubleshooting Procedures ... . .... .....',........."' '14-234
Symptom-to-ComPonent Chart
Electrical System - '96 - 98 Models ......'..... '14-234
Electrical System -'99 - 00 Models ..'....-..-. '11-210
Electrical Troubleshooting
Troubleshooting Flowcharts('96 - 98 Models) """'11-242
Troubleshooting Flowchart
('99 - 0O Modets) ...... 14-265
Linear Solenoids/lnhibitor Solenoid
Test ......................... . ...... 14-29f
Drive Pulley/Driven Pulley/Secondary Gear
Shaft Speed Sensors
Replacement .........'...... .14-292
Start Clutch Control
Start Clutch Calibration Procedure ....... ....,. 14-293
Hydraulic SYstem
Symptom-to-ComPonent Chart
Hydraulic System '.'.......14-294
Road Test ............................ 14-296
Stall Speed
Test......................... ...... 14-294
Fluid Level
Checking/Changing ....... 14-299
Pressure Testing ................. 14-300
Lower Valve BodY AssemblY
Replacement ..........,... 14-302
ATF Filter
Removal/lnstallation ..... 14-303
Transmission
Transmission
Removal ........... . 14-304
lllustrated Index
Transmission/Lower Valve BodY
Assembly ................. 14-308
Transmission Housing/Flywheel Housing ... 14-310
End Cover/f ntermediate Housing ..........'.'.... 14-312
Transmission Housing/Lower Valve Body Assembly
Removal ..........'.... .. " 14-314
Transmission Housing/Flywhesl Housing
Removal ................. ........ 1+316
End Cover/lntermediate Housing
14-318Removal .........,...............
Manual Valve Body
Disassembly/lnspection/Reassemblv .'.'.'..... 1 4-320
Forward Clutch
lltustrated Index ........................................ 14-321
Disassemblv .................. 14-322
Reassemblv , ,, . ',','......14-324
Secondary Gear Shaft
25 x 35 mm Thrust Shim Selection ..'.'....-... 14-324
Differential
lllustrated lndex ...,.....................,.,...-.-.-...'... 14-329
Backlash Inspection .-....14-329
Bearing Replacement ......'........'....'... ....'... 14-330
Differential Carrier Replacement ........'........ 14-330
Oil Seal Removal ........... 14-331
Oil Seal Installation/Side Clearance ....... . . 14-331
Flywheel Housing Input Shaft Oil Seal
Replacement .....,.... ...'.'.. 14-333
Transmission Housing Bearings
Driven Pulley Shaft Bearing
Replacenient ...................'. . ...................'.. 14-334
Secondary Gear Shaft Bearing
Reolacbment ...................... . .......... . ........ 14-335
Flywheel Housing Beating
Secondary Gear Shaft BearingReo1acement..................,........................... 14-335
Ring Gear Bearing
Replacement......... ........ 14-336
Control Shaft Assembly
Removal/lnstallation ....................'........... 14-336
Transmission
Reassembly .................. 14-338
Flywheel/Drive Plate .. . ...... . ...... ... . ....-.....'.'...14-341
Transmission
lnstalation ..................... 14-348
Cooler Flushing .'......... 14-352
shift cable
Removal/lnstallation....'........." """ 14-354
Adjustment .......'........ 14-355
Shift Lever ........................,. 14'356
Shift Indicator Panel
Adjustment ................ 14-357
ATF Cooler/Hoses
lnsta llation ......,,...... .... 14-357

Description
The Continuously Variable Transmission (CVT) is an electronically controlled automatic transmission with drive and driv
en Oullevs, and a steel belt. The CVT provides non stage speeds forward and one reverse. The entire unit is positioned in
line with the engine.
Transmission
Around the outside of the flywheel is a ring gear which meshes with the starter pinion when the engine is being staned.
The transmission has four parallel shafts: the input shaft, the drive pulley shaft. the driven pulley shaft, and the secondary
gear shaft. The input shaft is in line with the engine crankshaft. The drive pulley shaft and the driven pulley shaft consist of
movable and fixed face pulleys. Both pulleys are linked by the steel belt.
The input shaft includes the sun gear. The drive pulley shaft includes the forward clutch which mounts the carrier assem-
bly on the forward clutch drum. The carrier assembly includes the pinion gears which mesh with the sun gear and the ring
gear. The ring gear has a hub-mounted reverse brake disc.
The driven pulley shaft includes the start clutch and the secondary drive gear which is integral with the park gear' The sec-
ondary gear shaft is positioned between the secondary drive gear and the final driven gear. The secondary gear shaft
includes the secondary driven gear which serves to change the rotation direction. because the drive pulley shaft and the
driven oullev shaft rotate the same direction. When certain combinations of planetary gears in the transmission are
engaged by the clutches and the reverse brake, power is transmitted from the drive pulley shaft to the driven pulley shaft
to provide E, E, E, and El.
Electronic Control'96 - 98 Models:
The electronic control system consists of the Transmission Control Module (TCM), sensors, three linear solenoids, and a
inhibitor solenoid. Shifting is electronically controlled under all conditions'
The TCM is located below the dashboard, behind the kick panel on the driver's side.'99 - 00 Models:
The electronic control svstem consists of a Powertrain Control Module (PCM), sensors, three linear solenoids and an
inhibitor solenoid. Shifting is electronically controlled under all conditions. A Grade Logic Control System to control shift-
ing in E position while the vehicle is ascending or descending a slope.
The PCM is located below the dashboard, under the kick panel on the passenger's side.
Hydraulic Control
The lower valve body assembly includes the main valve body, the Pressure Low (PL) reguiator valve body, the shift valve
body, the start clutch control valve body, and the secondary valve body. They are positioned on the lower part of the
transmission housing.
The main valve body contains the Pressure High (PH) control valve, the lubrication valve, and the pitot regulator valve.
The secondary valve body contains the PH regulator valve, the clutch reducing valve, the start clutch valve accumulator,
and the shift inhibitor valve. The PL regulator valve body contains the PL regulator valve and the PH-PL control valve
which is ioined to the PH,PL control linear solenoid. The inhibitor solenoid valve is bolted on the PL regulator valve body.
The shift valve body contains the shift valve and the shift control valve. which is joined to the shift control linear solenoid.
The start clutch control valve body contains the start clutch control valve, which is joined to the start clutch control linear
solenoid. The linear solenoids and the inhibitor solenoid are controlled by the TCM or PCM. The manual valve body which
contains the manual valve and the reverse inhibitor valve, is bolted on the intermediate housing.
The ATF pump assembly is located on the transmission housing, and is linked with the input shaft by the sprockets and
the sprocket chain. The pulleys and the clutch receive fluid from their respective feed pipes, and the reverse brake receives
fluid from internal hydraulic circuit.
Shift Control Mechanism
Input from various sensors located throughout the vehicle determines which linear solenoid the TCM or PCM will activate.
Activating the shift control linear solenoid changes the shift control valve pressure, causing the shift valve to move. This
pressurizes the drive pulley pressure to the drive pulley and the driven pulley pressure to the driven pulley and changes
their effective pulley ratio. Activating the start clutch control linear solenoid moves the start clutch control valve. The start
clutch control valve uncovers the port, providing pressure to the start clutch to engage it(cont'd)
14-195
,!

Description
Clutches/Reverse Brake/Planetary Gear/Pulleys
Clulches/Reverse Brake
The CVT uses the hydraulically-actuated clutches and brake to engage or disengage the transmission gears. When
hydraulic pressure is introduced into the clutch drum and the reverse brake piston cavity, the clutch piston and the reverse
brake piston move. This presses the friction djscs and the steel plates together, locking them so they don't slip. Power is
then transmitted through the engaged clutch pack to its hub-mounted gear. and through engaged ring gear to pinion
gears.
Likewise, when the hydraulic pressure is bled from the clutch pack and the reverse brake piston cavity, the piston releases
the friction discs and the steel plates, and they are free to slide past each. This allows the gear to spin independently on its
shaft, transmitting no power.
Start Clutch
The start clutch, which is located at the end of the driven pulley shaft, engages/disengages the secondary drive gear.
The start clutch is supplied hydraulic pressure by its ATF feed pipes within the driven pulley shaft.
Forward Clutch
The forward clutch, which is located at the end of the drive pulley shaft, engages/disengages the sun gear.
The forward clutch is supplied hydraulic pressure by its ATF feed pipe within the drive pulley shaft.
Reverse Brake
The reverse brake, which is located inside the inte.mediate housing around the ring gear, locks the ring gear in E posi-
tion. The reverse brake discs are mounted to the ring gear and the reverse brake plates are mounted to the intermediate
housing. The reverse brake is supplied hydraulic pressure by a circuit connected to the internal hydraulic circuit.
Planetary Gear
The planetary gear consists of a sun gear, a carrier assembly, and a ring gear. The sun gear is connected to the input shaft
with splines. The pinion gears are mounted to the carrier which is mounted to the fo.ward clutch drum. The sun gear
inputs the engine power via the input shaft to the planetary gear, and the carrier outputs the engine power. The ring gear
is only used for switching the rotation direction of the pullev shafts,
In E. E, and E positions (forward range), the pinion gears don't rotate and revolve with the sun gear, so the carrier
rotates. In E] positjon {reverse range), the reverse brake locks the ring gear and the sun gear drives the pinion gears to
rotate. The pinion gears rotate and revolve in the opposite direction from the rotation direction of the sun gear, and the
carrier rotates with pinion gear revolution.
Pulleys
Each pulley consists of a movable face and a fixed face, and the effective pulley .atio changes with engine speed. The
drive pulley and the driven pulley are linked by the steel belt.
To achieve a low pulley ratio, high hydraulic pressure works on the movable face of the driven pulley and reduces the
effective diameter of the drive pulley. and a lower hydraulic pressure works on the movable face of the drive pulley to
eliminate the steel belt slippage. To achieve a high pulley ratio, high hydraulic pressure works on the movable face of the
drive pulley and reduces the eifective diameter of the driven pulley, and a lower hydraulic pressure works on the movable
face of the driven pulley to eliminate the steel belt slippage.
b
14-198

Description
Electronic Control System ('gG - 98 Modelsl (cont'dl
Circuit Diagram and Terminal Locations
GNITIONSWITCN
Pri - Pt coNTnoLLrN ns0LtN0t0
SIAiT CLUTCH CONTSOLLINEAFSOLENOID
sHtFT CONmOILINIAftSOLENOID
BFAXELIGHT
PAS|(ING 8MI(E SWITCH
i\c-...............- +B
i\--------.--_ rcr
: MAP(PBIg s61
E rtDiRxo
g TM8
scs
123518I1011't22578910
14172023261213t4t6171820
D
14-204