Honda Civic Service Manual page 713

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 torque
converter through a fluid passage. causing the lock-up
piston to be held against the torque convener cover. As
this takes place, the mainshaft rotates at the same speed
as the engine crankshaft, Together with the hydraulic
c o n t r o l , t h e P C M o p t i m i z e d t h e t i m i n g o f t h e l o c k _ u p
system. Under certain conditions, the lock_up clutch is
applied 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 the
linear solenoid. When lock-up control solenoid valves A
and B activate, modulator pressure changes. Lock_up
control solenoid valves A and B and the linear solenoid
a r e m o u n t e d o n t h e o u t s i d e o f t h e t o r q u e c o n v e r t e r
housing. 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 CONTROL
SOLENOID VALVE
Lock-up
Conditions
Lock-up Control
Solenoid Valve
Lineal
Solenoid
Pressure
A B
Lock-up OFF
OFF
OFF
Hig h
Lock-up. Half
O N
Duty operation
OFF - ON
Lock-up. Full
ON
ON
H i g h
Lock-up
during
deceleration
ON
Duty operation
OFF * ON
Low
TOROUE CONVERTER
CHECI( VALVE
RELIEF VAI-VE
LOCK.UP TIMING
VALVE
^
r______rr
r cooLER RELTEF VALVE
14-34
ATF PUMP