1999 HONDA CIVIC ac line

I
3. 3rd Gear
As the soeed of the vehicle reaches the prescribed value, shift control solenoid valve B is turned OFF by means ol the
pCM. Shift control solenoid valve A remains ON. The modulator pressure (6) flows to the right end of the 1-2 shift
valve and the left end oJ the 2-3 shift valve. The 2-3 shift valve is moved to the right side by the modulator pressure
(68). The 2-3 shift valve covers the port to stop line pressure (5) to the 2nd clutch and uncovers to the 3-4 shift valve
as the 2-3 shift valve is moved to the right side. The line pressure (5) becomes the 3rd clutch pressure (30) at the 3-4
shift valve. The 3rd clutch pressure (30) is applied to the 3rd clutch, and the 3rd clutch is engaged'
Fluid flows by way of:- Line Dressure (4) * CPB Valve - Line Pressure (5) * 1-2 Shift Valve - Line Pressure (5) * 2-3 Shift Valve
- Line Pressure (5) * 3-4 Shift Valve - 3rd Clutch Pressure (30) - 3rd Clutch
The hvdraulic pressure also flows to the 1st clutch. However, no power is transmitted because of the one-way clutch
as in 2nd gear.
NOTE: When used, "|eft" or "right" indicates direction on the hydraulic circuit.
14-29

Description
Hydraulic Flow lcont'dl
4th Goar {E Position}
As the speed of the vehicle reaches the prescribed value, shift controlsolenoid valve A is turned OFF bymeans ofthePCM Shift control solenoid valve B remains oFF. The modulator pressure (6) flows to the left end of the t-2 shiftvalve and the left end of the 3-4 shift valve. The modulator pressure (64) in the left end of the 1-2 shift valve equalsthe modulator pressure {68) in the right end of the 1-2 shift valve, the 1-2 shift valve remains at left side by the ten-sion of the valve spring.
The 3-4 shift valve is moved to the right side by the modulator pressure (64). The 3_4 shift valve covers the port to the3rd clutch and uncovers the port to the 4th clutch as this valve is moved to the right side. The 4th clutch pressure (4.1)from the 3-4 shift valve becomes the 4th clutch pressure (40) at the manual valve. The 4th clutch pressure (401 isapplied to the 4th clutch, and the 4th clutch is engaged.
Fluid flows by way of:- Line pressure (4) * CPB Valve - Line Pressure (5) + 1-2 Shift Valve - Line pressure (5) * 2-3 Shift Valve- Line Pressure (5) - 3-4 Shift Valve - 4th Clutch pressure (41) + Manual Valve _ 4th Clutch pressure (40)* 4th Clutch
The hydraulic pressure also flows to the lst clutch. However, no power is transmitted because of the one-way crutchas in 2nd and 3rd gear.
NOTE: When used, "|eft" or "right,, indicates direction on the hydraulic circuit.
\
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L
E Position
The flow of fluid through the torque convefter circuit is the same as in E position The line pressure (1) changes to the
line pressure (3) and flows to the l-2 shift valve. The iine pressure (3) changes to the line pressure (3') at the 'l-2 shift valve
and flows to the servo valve. The servo valve is moved to the right side (Reverse range position) and uncovers the port to
allow line pressure {3") to the manual valve, The line pressure {3') from the 1-2 shift valve flows through the servo valve to
the manual valve and changes the 4th clutch pressure (40). The 4th clutch pressure (40) is applied to the 4th clutch, and
the 4th clutch is engaged,
Reverse Inhibitor Control
When the E position is selected while the vehicle is moving forward at spe€ds over 6 mph (10 km/h)' the PCM outputs the
1st speed signal to shift control solenoid valves A and B; shift control solenoid valve A is turned oFF, shift control solenoid
valve B is turned ON. The 1-2 shift valve is moved to the right side and covers the port to stop line pressure (3') to the
servo valve. The line pressure (3') is not applied to the servo valve, and the 4th clutch pressure (40) is not applied to the
4th clutch, as a result, power is not transmitted to the reverse direction'
When used. 'left" or "right" indicates direction on the hydraulic circuit'
14-31

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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Description
Lock-up System (cont'd)
TOROUE CONVERTER
In B.rl position, in 3rd and 4th, and lDl_- position in 3rd.pressurized fluid is drajned from the back of the torqueconverter through a fluid passage. causing the lock-uppiston to be held against the torque convener cover. Asthis takes place, the mainshaft rotates at the same speedas the engine crankshaft, Together with the hydrauliccontrol, the PCM optimized the timing of the lock_upsystem. Under certain conditions, the lock_up clutch isapplied during deceleration, in 3rd and 4th gear.
The lock-up system controls the range of lock_up accord_ing to lock-up control solenoid valves A and B. and thelinear solenoid. When lock-up control solenoid valves Aand B activate, modulator pressure changes. Lock_upcontrol solenoid valves A and B and the linear solenoidare mounted on the outside of the torque converterhousing. and are controlled by the pclvl.
Lock-up Conditions/Lock-up Control Solenoid Valves/Linear Solenoid Pressure
MODULATOR PRESSURE
.-- LINEAR SOLENOID PRESSURE
LOCK.UP CONTROL. VALVE
LOCK.UP CONTROLSOLENOID VALVELock-up
Conditions
Lock-up Control
Solenoid ValveLineal
Solenoid
PressureAB
Lock-up OFFOFFOFFHig h
Lock-up. HalfONDuty operation
OFF - ON
Lock-up. FullONONHigh
Lock-up
during
decelerationONDuty operation
OFF * ONLowTOROUE CONVERTERCHECI( VALVE
RELIEF VAI-VE
LOCK.UP TIMINGVALVE
^ r______rr r cooLER RELTEF VALVE
t'-
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ATF PUMP

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
14-35

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
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