Engine HONDA CR-V 1997 RD1-RD3 / 1.G Workshop Manual

Shift Control
The PCM determines which gear should be selected by various signals sent from sensors, and actuates the shift control
solenoid valves A and B to control shifting. Also. a Grade Logic Control System has been adopted to control shifting in E
anO E ('gZ - gg), and E ('99 - 00) position while the vehicle is ascending or descending a slope, or reducing speeo.
PositionGearShift Control Solenoid
Valve A
Shift Control Solonoid
Valve B
E, E, Or
E
'I stOFFON
2ndONON
3rdONOFF
E orE4thOFFOFF
a2ndONON
tr1stOFFON
E-ReverseONOFF
*See page 14-37 for reverse inhibitor control description.
Lock-up Control
From sensor input signals, the PCM determines whether to turn the lock-up ON or OFF, and activates lock-up control
solenoid valve A and/or B accordingly. Lock-up does not occur until the engine is warm. The combination of driving sig-
nals to lock-up control solenoid valves A and B and the linear solenoid pressure is shown in the table below.
Lock-up ConditionsLock-up Control
Solonoid Valve A
Lock-up Control
Solenoid Valve B
Linear Solenoid
Pressuro
LOCK-Up \JrrOFFOFFHigh
Lock-up, HalfONDuty operation
OFF - ON
Lock-up, FullONONHish
Lock-up
during decelerationONDuty operation
OFF - ONLow
(cont'd)
14-17
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Description
Electronic Control System (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 vehicle speed
sensor, the throttle position sensor, the barometric pressure sensor ('98 model). the engine coolant temperature sensor, the
brake switch signal, and the shift lever position signal, to control shifting while the vehicle is ascending or descending a
slope, or reducing speed.
SIGNALS DETECTED
Driving Rcsisl.nce
Judgemont ot Controlling Aroa
. Normal Modo {Flrt ro.d mode}. Ascending Mode. Deacending Mode. Deceleration Mode
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Description
Electronic Control System (cont'd)
Descending Control
When the PCM determines that the vehicle is going down a hill in E and @ positions ('97 - 98 models). and in @ posi-
tion {'99 - 00 models), the shitt-up speed from 3rd to 4th gear and from 2nd to 3rd (when the throttle is closed) becomes
faster than the set speed for flat road driving to widen the 3rd gear and 2nd gear driving areas. This, in combination with
engine braking from the deceleration lock-up, achieves smooth driving when the vehicle is descending. There are three
descending modes with different 3rd gear driving areas and 2nd gear driving areas according to the magnitude of a gradi-
ent stored in the PCM. When the vehicle is in 4th gear, and you are decelerating when you are applying the brakes on a
steep hill, the transmission will downshift to 3rd gear, When you accelerate, the transmission will then return to higher
gear.
2ND - 3RD 3RD - 4TH
o50
F
DESCENDING MODE: Downshift Schodule
- : FLAT ROAD MODE
----'-----' I GRADUAL DESCENDING MODE
- - - - - : MEDIUM OESC€NOING MODE
. . ... : STEEP DESCENDING MODE
62 mph Vehicle sp€ed1100 km/hl
Deceleration Control
When the vehicle goes around a corner, and needs to decelerate first and then accelerate, the PCM sets the data for deceleration
control to reduce the number of times the transmission shifts. When the vehicle is decelerating from speeds above 27 mph(4i| km,ih), the PCM shifts the transmission from 4th to 2nd earlier than normal to cope with upcoming acceleration,
14-20
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Description
Hydraulic Control
The hydraulic control system is controlled by the ATF pump, valves, accumulators, and electronically controlled solenoids.
The ATF pump is driven by splines on the end of the torque converter which is aftached to the engine. Fluid from the ATF
pump flows through the regulator valve to maintain specified pressure, through the main valve body, to the manual valve,
directing pressure to each clutch. The valve body includes the main valve body, the regulator valve body, the lock-up
valve body, the secondary valve body, the servo body, the linear solenoid, the shift control solenoid valve Ay'B assembly,
and the lock-up control solenoid valve A/B assembly. The shift control solenoid valve A,/B assembly and the linear
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.
LINEAR
SHIFT CONTROLSOLENOID VALVE A/BASSEMBLY
SECONDARY VALVEBODY
REGULATORVALVE BOOY
VALVE BODY
SOLENOID VALVE A/BASSEMELY
N
ATF PUMP GEARS
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Regulator Valve
The regulator valve maintains constant hydraulic pressure from the ATF pump to the hydraullc control system, while also
furnishing fluid to the lubricating system and torque converter. Fluid from the ATF pump flows through B and B'. Fluid
entering from B flows through the valve orifice to the A cavity. This pressure of the A cavity pushes the regulator valve to
the right side. and this movement of the regulator valve uncovers the fluid port to the torque converter and the relief
valve. The fluid flows out to the torque converter and the relief valve, and the regulator valve moves to the left side.
According to the level of the hydraulic pressure through B, the position of the regulator valve changes and the amount of
fluid from B,through the torque converter also changes. This operation is continued, maintaining the line pressure.
NOTE; When used, "|eft" or "right" indicates direction on the illustration below.
ENGINE NOT RUNNING
STATOR SHAFT ABM
Stator Reaction Hydraulic Pressurs Control
Increases in hydraulic pressure according to torque are performed by the regulator valve using stator torque reaction. The
stator shaft is splined to the stator in the torque converter, and its arm end contacts the regulator spring cap When the
vehicle is accelerating or climbing (Torque Converter Range), stator torque reaction acts on the stator shaft, and the stator
arm pushes the regulator spring cap in the direction of the arrow in proportion to the reaction. The stator reaction spring
compresses, and the regulator valve moves to increase the line pressure. Line pressure reaches its maximum when the
stator torque reaction reaches its maximum.
TOROUE CONVERTER
REGULATON VALVE
STATOR REACTION
TOR SPRING CAP
(cont'd)
ENGINE RUNNING
To TOROUE CONVERTER Lubtication
STATONSTASHAFTATOF SHAFT ARM
14-27
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Description
Hydraulic Flow (cont'dl
lll Position
As the engine turns, the ATF pump starts to operate. Automatic transmission fluid (ATF) is drawn from (99) and dis-charged into (1). Then, ATF flowing from the ATF pump becomes line pressure ('l). Line pressure (1) js regulated by theregulator valve. Torque converter inlet pressure {92) enters (94) of the torque conveTter through the lock-up shift valve anddischarges into (90) The torque converter check valve prevents torque converter pressure from rising. Under this condi-tion, hydraulic pressure is not applied to the clutches.
NOTE;
. When used. "|eft" o. "right" indicates direction on the hvdraulic circutt.. The hydraulic circuit shows the '97 - 98 models {7 positions}; the '99 - 00 models (6 positions) is similar.
'lF'.j.l
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E] or E Position ('97 - 98 Models), and D Position ('99 - 00 Modelsl
1. lst Gear
Fluid flow through the torque converter circuit is the same as in E] position. Line pressure flows to the manual valve
and the modulator valve. Line pressure changes to modulator pressure (6) at the modulator valve and to line pressure
{4) at the manual valve. Modulator pressure (6) flows to the left end of the 1-2 shift valve and the 3-4 shift valve
because shift control solenoid valve A is turned oFF and B is turned oN by the PcM. The 1-2 shift valve is moved to
the right side. Line pressure {4) changes to 'lst clutch pressure (10} at the 1-2 shift valve and the orifice The 1st clutch
pressure (10) is applied to the 1st clutch and the 1st accumulator; the vehicle will move as the engine power is trans-
mitted.
NOTE:
. When used, "left" or "right" indicates direction on the hydraulic circuit.
. The hvd rau lic circuit shows th e '97 - 98 models (7 positions); the '99 - 00 models {6 positions) issimilar.
(cont'dl
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Lock-up System
TOROUE CONVERTER
In E position ('97 - 98 models) and in E position ('99 -
OO models) (3rd and 4th), and E position ('97 - 98 mod-
els) and in E position with Over-Drive (O/D) is OFF (by
pressing the O/D switch) ('99 - 00 models) (3rd), pressur-
ized fluid is drained from the back of the torque convert-
er through a fluid passage, causing the lock-up piston to
be held against the torque converter cover, As this takes
Dlace, the mainshaft rotates at the same speed as th8
engine crankshaft. Together with the hydraulic control,
the PCM optimizes the timing of the lock-up system.
Under certain condltions. the lock-up clutch is appli€d
during deceleration, in 3rd and 4th gear.
The lock-up system controls the range of lock-up sccord-
ing to lock-up control solenoid valves A and B, and ths
linear solenoid. When lock-up control solenoid valves A
and B activate. modulator pressure changes. Lock-up
control solenoid valves A and B are mounted on the out-
side of the torque converter housing, and the linear
solenoid is mounted on the transmission housing. They
are controlled bv the PCM.
The table below shows the lock-up conditions for lock-up
control solenoid valves and linear solenoid pressure.
LINEAR SOLENOID PRESSURE
(cont'd)
LOCK.UP CONTROL' VALVE
LOCK.UP CONTROLSOLENOID VALVE
AB
MODULATORPf,ESSURE
MAINSHAFT
COUNTERSHAFT
SUB.SHAFT
Lock-up
Conditions
Lock-up Conirol
Solenoid valveLinaal
Solenoid
PrgssulsAB
Lock-up OFFOFFOFFHigh
Lock-up, HalfONDuty operation
OFF - ONLow
Lock-up, FullONONHigh
Lock-up
during
deceleration
ONDuty operation
OFF - ON
RELIEF VALVE
LOCK'UP TIMINGVALVE
COOLER RELIEF VALVE
ATF COOLERATF STRAINER
ATF PUMP
14-39
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Description
Lock-up System (cont'dl
Lock-up Clutch
L Ooeration (clutch on)
With the lock-up clutch on, the fluid in the chamber between the torque convener cover and the lock-uD oiston is drainedoff, and the converter fluid exerts pressure through the piston against the torque converter cover, As a result, the conven-er turbine is locked to the converter cover. This bipasses the converter, placing the vehicle in direct drive.
LOCK,UP PISTON
The power flows by way of:
Engine
+
Drive plate
Torque converter cover
I
Lock-up piston
t
Damper spring
{
Turbine
Mainshaft
IOROUECOVER
Operation (clutch off)
With the lock-up clutch off, the fluid flows in the reverse of "clutch on." As a result, the lock-up piston moves away fromthe converter cover, and the torque converter lock-up is released.
Engine
I
Drive plate
{
Torque converter cover
{
Pump
I
Turbine
{
Mainshaft
TOROUECOVER
To ATF cooler{(1\\n1INLET
t
Jtl
ort
MAIf{SHAFT
MAII{SHAFT
14-40
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