1996 HONDA CIVIC acc control

PCM Terminal Voltage/Measuring Conditions ('99 - 00 Models)
A/T Control System
The PCM terminal voltage and measuring condjtions are shown for the connector terminals that are related to the A//T con-trol system, The other PCM terminal voltage and measuring conditions are described in section ,11.
PCM Connoctor Tgrminrl Locations
PCM CONNECTOR A {32PI
PCM CONNECTOR 8 (25P}
Terminal NumbelSignalDescriptionM€asuring Conditions/Terminal Voltage
A105L5Service check signalWith ignition switch ON (ll) and service check
connector open: Approx, 5 V
With ignition switch ON (ll) and service check
connector connected with sDecial tool: 0 V
A14D4 INDE indicator light controlWhen ignition switch is first turned ON (ll):
ApDrox. 10 V for two seconds
In E position: Approx. 1O V
428ILUInterlock ControlWhen ignition switch ON (ll), brake pedal
depressed, and accelerator pedal rereaseo:
Battery voltage
A.32STOP SWBrake switch signal inputBrake pedal depressed: battery voltage
Brake oedal released:0 V
Terminal NumberSignalDescdptionMeasuring Condhions/Torminal Voltag6
B1!GP1Power supply systemWith ignition switch ON (ll): Battery voltage
With ignition switch OFF: 0 V
PGlGround
B8LS AMLinear solenoid power supply
negative electrode
With ignition switch ON (ll): Pulsing signal
B9IG P2Power supply systemWith ignition switch ON (ll): Baftery voltage
With ignition switch OFF: 0 V
810PG2G rou nd
917LS APLinear solenoid power supplypositive electrode
With ignition switch ON (ll): Pulsing signal
B20Ground
VBUBack-up power supplyAlways battery voltage
822Ground
\
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Main Valve Body
Disassembly/lnspection/Reassembly
NOTE:
. Cleanall parts thoroughly in solvent or carburetor cleaner, and drywith compressed air. Blowoutall passages.. Replace the valve body as an assembly if any pans are worn or damaged.. Check all valves for free movement. lf anyfail toslidefreely, see Valve Body Repairon page,l4-139.. Coat all parts with ATF during assembly.
CAUTION: Do not use a magnet to removs tha check balls; it may magnetizo the balls.
CPB VALVEVALVE CAP CLIP
ORIFICE CONTROL VALVE
BALLS, 8
lST ACCUMULATOR CHOKE
MODULATORVALVE
RELIEF VALVEVALVE
MAIN VALVE EODYInspect for wear, scratchesand scoring.
SEBVO CONTROL VAL
I.2 SHIFT VALVE
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VALVE CAP

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)
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,!

Electronic Control System ('96 - 98 Modelsl
The electronic control system consists of the Transmission control Module (TcM), sensors, three linear solenoids, and an
inhibitor solenoid. Shifting is electronically controlled under all conditions
The TCIM is located below the dashboard, behind the kick panel on the driver's side'
The TcN4 controls the transmission to reduce engine speed and retain the engine's cooling efficiency when the vehicle is
driven with Iull throttle acceleration
lf the vehicle is continuously driven at full throttle acceleration, the TCM regulates the pulley hydraulic pressure to
increase the pulley ratio, which, as the result. reduces the engine speed and retains the designed cooling efficiency After
the vehicle has been driven at a lower engine speed for a while, the TCM increases the pulley ratio to the original ratio.
For smooth starting in the E position, the TcM sends a signal to the EcM to cut off the rvc clutch {if the A!/c is on) and
increases the engine speed to 900 rpm when the transmission is shifted to the E position'
The start clutch functions to make smooth starting possible. To let the start clutch function properly. the TCM regulates
the start clutch hydraulic pressure based on the entine's negative pressure memorized in the E position'
:
:
z
z
z
S*ond.ry G..r Sh:ft
(cont'd)
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Electronic Gontrol System ('99 - 00 Modelsl
The electronic controt system conststs 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'
fn"pCVirlocatedbelowthedashboard,underthekickpanelonthepassenger'sside'
The pCM controls the transmassion to reduce engine speed and retain the engine's cooling efficiency when the vehicle is
driven with full throftle acceleration
lf the vehicle is continuously driven at lull throttle acceleration, the PCM regulates the pulley hydraulic pressure to
increase the pulley ratio which. as the result, reduces the engine speed and retains the designed cooling efficiency After
the vehicle has been driven at a lower engine speed for a while, the PCM increases the pulley ratio to the original ratio'
i"i ".nl",rr starting in the E position, the PcM cuts off the ,Vc clutch (if the A/c is on) and increases the engine speed to
900 rpm when the transmission is shifted to the E position'
The start clutch functions to make smooth starting possible. To let the start clutch function properly, the PcM regulates
the start clutch hydraulic pressure based on the engine's negative pressure memorized in the E position'
FCM
s*o.d.ry G..t Sh.h
(cont'd)
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Description
Electronic Control System ('99 - 00 Modelsl (cont'dl
Grade Logic Control System
How it works:
The PcM compares actual driving conditions with memorized driving conditions. based on the input from the vehiclespeed sensor, the throttle position sensor, the manifold absolute pressure sensor, the engine coolant temperature sensor,the brake switch signal, and the shift lever position signal, to control shifting while the vehicle is ascending or descendinga slope.
Ascending Control
When the PCM determines that the vehicle is climbing a hill in E position, the system selects the most suitable shiftschedule (pulley ratio) according to the magnitude of a gradient. so the vehicle can run smooth and have more powerwhen needed. There are three ascending modes with different shift schedules according to the magnitude ot a gradient inthe PCM.
Descending Control
when the PCM determines that the vehicle is going down a hill in E position. the system selects the most suitable shiftschedule (pulley ratio) according to the magnitude of a gradient. This, in combinstion with engine braking, achievessmooth driving when the vehicle is descending, There are three descending modes with different shift schedules accord-ing to the magnitude of a gradient in the PCM.
L
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Description
Hydraulic Control
The hydraulic control system is controlled by the ATF pump. the valves, and the solenoids. The ATF pump is driven by theinput shaft. The ATF pump and the input shaft are linked by the ATF pump drive chain and the sprockets, The inhibitorsolenoid valve and the linear solenoids. which are located on their valve body, are controlled by the TCM or pcM. Fluidfrom the ATF pump flows through the PH regulator valve to maintain specified pressure to the drive pulley, the driven pul-ley, and the manual valve,
The lower valve body assembly includes the main valve body, the PL regulator valve body, the shift valve body, the startclutch control valve body, and the secondary valve bodv.
Main Valve Eody
The main valve body contains the pH control valve, the rubrication valve, and the pitot regulator valve.
PH Control Valve
The PH control valve supplies PH control pressure (PHCI in accordance with the pH-pL control pressure (HLc), and sup-plies PH control pressure to the PH regulator valve, which also regulatss PH pressure. At kick-down, it increases pHcontrol pressure which increases the high (PH) pressure. This shortens the shift speed by releasing the reverse inhibitorpressure (Rl)from the inhibitor solenoid valve.
Lubrication Valve
The lubrication valve controls the lubrication pressure to each shaft and maintains lubrication pressure. When rne pres-sure is too high, the spring is compressed. This moves the lubrication valve and opens the fluid leak passage.
Pitot Regulalor Valv6
The pitot regulator valve controls the start clutch pressure (SC) in accordance with the engine speed, when the electron-ic control system is faulw.
MAIN VAIVEBODY
L.
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Secondary Valve Body
The secondary valve body contains the PH regulator valve. the clutch reducing valve' the start clutch valve accumulator'
and the shift inhibitor valve
PH Regulator Valve
The pi regulator valve maintains hydraulic pressure supplied from the ATF pump. and supplies PH pressure to the
hvdraulic control circuit and the lubrication circuit. PH pressure is regulated at the PH regulator valve by the PH control
pressure (PHC) from the PH control valve.
Cluteh Reducing Valvo
The clutch reducing valve receives PH pressure from the PH regulator valve and regulates the clutch reducing pressure
(cR). The clutch reducing valve supplies clutch pressure (cR) to the manual valve and the start clutch control valve' and
supplies signal pressure to the PH-PL pressure control valve. the shift control valve, and the inhibitor solenoid valve'
Start Clutch Valv€ Accumulator
The start clutch vatve accumutator stabilizes the hydraulic pressure that is supplied to the start clutch'
Shift Inhibitor Valve
The shift inhibitor valve switches the fluid passage to switch the start clutch control from electronic control to hydraulic
control when the electronic control system is faulty. lt also suppliss clutch reducing pressure (cR) to the pitot regulator
valve and the pitot lubrication pipe.
START CLUTCH VALVE
SECONDARY VALVEBODY
SHIFT INHIBITOE VALVE
(cont'd)
PH REGULATOR VAL
REDUCING VALVE
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