1999 HONDA CIVIC Shift

GRADE LOGIC CONTROL SYSTEM
How it works:
The pCM compares actual driving conditions with driving conditions memorized in the PCM, based on the input from the
vehicle speed sensor, the throttle position sensor, the barometoric pressure sensor, the engine coolant temperature sensor,
the brake switch signal, and the shift lever position signal, to control shifting while a vehicle is ascending or descending a
slope, or reducing speed.
SIGNALS OETECTED
O.iving Resi3lence
Judgemenl ot Conirolling Arca
. Ascending mod€
lFuzzy loqicl. Gradual Ascending mode' Ste€p Ascending mode. Oescending mode. Gr.du.l Descending mode. Steep D6cending mode
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Description
Electronic Control System {cont'dl
Ascending Control
When the PCM determines that the vehicle is climbing a hill in E position, the system oxtends the sngagement area of2nd gear and 3rd gear to prevent ths transmission from fr€quently shifting between 2nd and 3rd gears, and between 3rdand 4th gears, so the vehicle can run smooth and have more power when needed. There are two ascending modes withdifferent 3rd gear driving areas according to the magnitude of a gradient stored in the pCM.
NOTE:
. The PCM memory contains shift schedules between 2nd and 3rd gears, and between 3rd and 4th gears that enable thePCM's fuzzy logic to automatically select the most suitable gear according to the magnitude of a gradient. Fuzzy logic is a form of artificial intelligence that lets computers respond to changing conditions much like a humanmind would,
Dssconding Control
When the PCM determines that the vehicle is going down a hilt in E position, the shift-up speed from 3rd to 4th gearwhen th€ throftle is closed becomes faster than the set speed for flat road driving to widen the 3rd gear driving area.This, in combination with engine braking from the deceleration lock-up, achieves smooth driving when the vehicle isdescending. There are two descending modes with different downshift (4 - 3) schedules according to the magnitude of agradient stored in the PCM. When the vehicle is in 4th gear, and you are decelerating on a gradual hill, or when you areapplying the brakes on a steep hill, the transmission will downshift to 3rd gear. When you accel6rate, the transmission willthen return to 4th gear.
ASCENDING MODEDESCENDING MODE
4TH SHIFTING
L.
F
CHARACTERISIICSCONTROL AREA
ff.1"11", vehicr. 3pe€dff;Tlr., vohicre speed
GRADUAL ASCENOINGCONTROL AREA
Docel6ration Control
When the vehicle goes around a corner. and needs to first decelerate and then accelerate. the rcM sets the data for decelerationcontrol to reduce the number of times the transmission shifts. When the vehicle is decelerating from speeds above 26 mph(41 km/h), the rcM shifts the transmission from 4th to 2nd earlier than normal to cope with upcoming acceleration.
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Description
Electronic Control System (cont'dl
Circuit Diagram and Terminal Locations -'99 - O0 Models
GNTONSWICH,,--b. rcj
LI
LOCK.UPCONIFOLSOLEI\Q D VALVE A
LOCK UP CON'IROLSOLENODVALVEB
SH FI CONTROL
SHIFTCONTFOLSOLENOIDVALVEE
L NEAF SOLEIOIO
PG2
IGP2
v3u
vcc2
sc2
6NII ON SWICH
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Hydraulic Control
The hydraulic control system is controlled by the ATF pump, valves, accumulators, and electronically controlled solenoids'
TheATFpUmpisdrivenbysp||nesontheendofthetorqueconverterWhichisattachedtotheengine.F|uidfromtheATF
pumpf|owsthroughtheregu|atorva|vetomajntainspecifiedpressurethroughthemainva|vebodytothemanuaIva|ve'
directingpressuretoeachofthec|utches.Theva|vebodyinc|udesthemainvaivebody,theregu|atorvalvebody,the
|ock-upva|vebody,thesecondaryVa|vebody,theservobody,theIinearso|enoid,theshiftcontro|so|enoidva|velVB
assembly, and the lock up control solenoid valve A/B assembly. The shift control solenoid valve Ay'B assembly and the lin-
ear solenoid are bolted on the outside of the transmission housing. The lock-up control solenoid valve A,/B assembly is
bolted on the outside of the torque converter housing
SHIFT CONTROLSOLENOIO VALVE A/8
ASSEMBLY
LINEAR SOLENOID
SERVO BOOY
REGULATORVALVE BODY
VALVE
VALVE BOOY
(cont'd)
CONTROLSOLENOID VALVE A/BASSEMBLY
ATF PUMP GEARS
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Description
Hydraulic Control (cont'dl
Msin Valve Body
The main valve body houses the manual valve, the 1-2 shift valve, the 2nd orifice control valve, the cpB valve, the modu-lator valve' the servo control valve, and the relief valve. The primary functions of the main valve body are to swatch fluidpressure on and off and to control the hydraulic pressure going to the hydraulic control svstem.
2ND ORIFICE CONTROTVALVE
1-2 SHIFT VALVE
RELIEF VALVE
CPC VAL
3-4 SHTFT V
VALVE
Socondary Valve Body
The secondary valve body is located on the main valve body. The secondary valve body houses the 2-3 shift vatve, the 3-4shift valve, the 3-4 orifice control valve, the 4th exhaust valve, and the CpC valve.
CONTROL
2.3 SHIFT VALVE
4TH EXHAUST VALV€
VALVE
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VALVE

\
Regulator Valve BodY
The regulator valve body is located on the main valve body. The regulator valve body consists of the regulator valve' the
torque-converter check valve, the cooler relief valve, and the lock-up control vaive'
REGULATOR VALVE
BODY
REGULATOR VALVE
COOLER RELIEF VALV€
LOCK,UP SHIFT VALVE
CONVERIER
CHECK VALVE
CONTROL VALVE
Lock-up Valve BodY
The lock-up valve body with the lock-up shift valve and the lock-up timing valve is located on the regulator valve bodv
LOCK-UP NMING VALVE
icont d
1+21

\
Servo Body
The servo body is located on the secondary valve body. The servo body contains the servo valve which is integrated with
the reverse shift fork, and the accumulators
2NO ACCUMULA
SERVO BODY
1ST ACCUMULATOR
3RD ACCUMULATOR
SERVO VALVE/SHIFTFORK SHAFT
NoTE: The illustration shows the'96 - '98 models; the '99 - 00 models are similar'
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Description
Hydraulic Flow
General Chart ol Hydraulic PressureATF Pump- pegurator varve -_l- Line pressure -f- Modurator pressure - Linear sorenoid
| -Clutch pressure
-Torque Converter pressure
t-Lubrication Pressure
Distribution of Hydraulic Pressur€. Regulator Valve -]- Torque Converter pressure
F_ Lubrication pressure
i- To regulate Line pressure
. Manual valve _ To select Line pressure _ clutch pressure
' Modulator Valve i/odulator pressure _ ___f_ Shift Control Solenoid Valves
F_ Lock_up Control Solenoid ValvesL_ Linear Solenoid
. 1-2 Shift Valve - l. 2-3 Shift Valve - 1- Ctutch pressure. 3-4 Shift Valve
lra
PORT NO.DESCRIPTION OF PRESSUREPORT NO.DESCRIPTION OF PRESSUREPORT NO.DESCRIPTION OF PRESSURE
1LINE6B
MODULATE(SHIFT CONTROL
SOLENOID VALVE B)
414TH CLUTCH
LINEMODULATE(LOCK-UP CONTROL
SOLENOID VALVE A)
56LINEAR SOLENOID
LINE6D
MODULATE(LOCK-UP CONTROL
SOLENOID VALVE B)
90TOROUE CONVEBTER
2LINE6D'
MODULATE
(LOCK-UP CONTROL
SOLENOID VALVE B)
91TOROUE CONVERTER
LINE7LINE92TOROUE CONVERTERLINE8LINE/CPC93ATF COOLER3"LINE9LINE94TOROUE CONVERTER4LIN E'101ST CLUTCH95LUBRICATION
LINE202ND CLUTCHYOTOROUE CONVERTERLINE20A2ND ACCUMULATOR97TOROUE CONVERTER5LINE99SUCTION
MODULATE303RD CLUTCHXDRAIN
6A
MODULATE(SHIFT CONTROL
SOLENOID VALVE A)
404TH CLUTCH
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