Acura 1994 Integra Service Manual page 432

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Partial Lock-up
Lock-up Control Solenoid Valve A: ON
Lock-up Control Solenoid Valve B: OFF
The TCM switches the solenoid valve A on to release the modulator pressure in the left cavity ol the lock-up shift vatve.
The modulator pressure in the right cavity of the lock-up shift valve overcomes the spring force, thus the lockiup shifi
valve is moved to the left side.
The modulator pressure is separated to the two passages:
F1: Torque Converter Inner Pressure: enters into right side-to engage lock-up clutch
F2: Torque Convener Back Pressure: enters into left side-to disenqage lock-up clutch
The back pressure (F2) is regulated by the lock-up control valve whereas the position of the lock-up timing B valve is
determined by the throttle B pressure, tension of the valve spring and pressure regulated by the modulator, Also the
position of the lock-up control valve is determinded by the back pressure of the lock-up control valve and torque conven-
er pressure regulated by the check valve. With the lock-up cont.ol solenoid valve B kept oft, the modulator p.essu.e is
maintained in the left end of the lock-up control valve; in other words, the lock-up control valve is moved slightly to the
left side. This slight movement of the lock-up conlrol valve causes the back pressure to be lowered slightly. resulting
in panial lock-up.
NOTE: When used. "left" or "right" indicates direction on the flowchart.
LOCK.UP COIIIROL
SO!ENO|o VALVE A
LOCK UP COIITROI
SOTENOID VALVE B
<- MODUI.AIOi PAESSUFE
7
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LOCK-UP IIMII{G B VATV€
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