2000 HONDA CIVIC ect

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.
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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
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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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E Position
Astheengineturns.theATFpumpa|sostartstooperate.F|uidfromtheATFpumpf|owstothePHregu|atorva|veandthe
c|Utchreducingva|ve.ThePHregu|atorva|veregu|ateshighpressure(PH).andsendittotheshiftVa|veandthePLregU'
latorvalve.Thehighpressure(PH)flowstothemovablefaceofthedrivenpulleyviatheshiftvalve'andturnsintolow
pressure(PL)atthePLregu|atorva|ve.Thelowpressure(PL}f|owstothemovab|e'aceofthedrivepu||eYviatheshift
valve. At this time, the pulley ratio remarns low'
Thehighpressure(px)uecomesttrectutchreducingpressure(CR)atthec|utchreducingva|Ve.Thec|utchreducingpres.
sure (CR) flows to the start clutch cont'oi uatt". tn"lt"n'al valve' the PH-PL control valve' and the shift control valve' and
is intercepted bY those valves
Under this condition, hydraulac pressure is not applied to the clutches and reverse brake'
(cont'd)
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E position, at middle sPeed range
Asthespeedofthevehic|ereachestheprescribedVa|ue,theshiftcontro||inearsolenoidisactivatedbytheTcMorPcM'
Theshiftcontro||inearso|enorocontroIsttresniftcontroIVa|vetoactivateshiftVa|vepressure(SV)'c|utchreducingpres-
sure (CR) trom the clutch reduclng valve becomes shift valve pressure (SV) at the shift control valve Shift valve pressure
(SV)flowstothe|eft"noottr'"st'ittu"tue.theshiftVa|Vetotherightsideandpositioningitinthemidd|eofitstrave|.The
shift valve covers th" pon ao ",oo nLior".irr" tiHl a ,tr" pulleys, and uncovers the port leading low pressure (PL) to the
pu eys. The drive pu ey and tne oriJen priLy |."""iu" to* pressure (PL). At this time, the pulley ratio is in the middle'
Pressure remains to apply the forward clutch and the start clutch'
NOTE: When used, "|eft" or "right" indicates direction on the hydraulic circuit'
(cont'd)
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Description
Hydraulic Flow (cont'd)
@ position, at high spe6d range
As the speed of the vehicle reaches the prescribed value, the shift control linear sol€noid moves the shift contror vatve toincrease shift valve pressure (SV) at the left end of the shift valve. ttre srrit vatve moves to the right side compared to itsposition at the middle pulley ratio. The shift valve uncovers the port leading high pressure (pxito ttre d.ve puley anduncovers the port leading low pressure (PL) to the driven pulley. The drive pu|ey receives high pressure (pH) and the driv-en pulley receives low pressure (pL). The pulley ratio is high.Pressure remains to apply the forward clutch and the start clutch,
NOTE: When used, "left,, or,,right" indicates direction on the hydraulic circuit.
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E position
The flow of fluid up to the drive pulley, the driven pulley' and the clutch reducing valve is the same as in E position The
pulley ratio is low b"car"" tt " o riu",i'prti"vi"""v"" t'igtr pressure.(pH) and the drive pulley receives low pressure {PL).
The manual valve is shifted into the B position, and it uncovers the port that leads reverse brake pressure (RVS) to the
reverse inhibitor valve. The inhibitoi Jenoid turns off by means of the TcM or PcM, and reverse inhibitor pressure (Rl) is
appliedtotherightendofthe,"u",""int,iui.o,u,|ve.Thereverseinhibitorva|vemovestothe|eftside,anduncoversthe
port that leads reverse brake pr"a"ur" tivst,o,he reverse brake. clutch reducing pressure (cR) becomes reverse brake
pressure (RVS) at the manuat *r"-, "nJ tro*" to the reverse brake. The reverse brake is engaged, and it locks the ring
gear.
NOTE: When used, "|eft" or "right" indicates direction on the hydraulic circuit'
(cont'd)
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Description
Hydraulic Flow (cont'dl
E position
Reverse Inhibitor Conirol
lf the E position is selected while the veiicle is moving forward at speeds over 6 mph (10 km/h), the inhibitor solenoiddoesn't turn off by means of the TcM or PCM Reverse inhibitor pressure (Rl) is not applied to the reverse inhibitor valveas the reverse inhibitor solenoid turns on. The reverse inhibitor valve is kept on the right side, and covers the pon ro sropreverse brake pressure {RVS} to the reverse brake from the manual valve. Reverse brike pressure (RVs) i; not appried tothe reverse brake, and power is not transmitted to the reverse direction.
NOTE: When used, "left,' or,,right,, indicates direction on the hydraulic circuit.
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