Ac system HONDA CR-V 1998 RD1-RD3 / 1.G Workshop Manual

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,
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Description
Electronic Control System (cont'd)
Circuit Diagram and Terminal LocationsrgS Model
GNTIONSWITCN
LOCK-UPCONIFOLSOLEIIO D VALVE A
LOCK-UPCONTSOLSOLEI.IO 0 vALvE B
SBIFICONTROLSOLEI€ DVALVE A
SH FTCONTFOLSOLEiDID VALVE 8
LIN€AA SOL€iDIDGNIION SWTCHtGr
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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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Main Valve Sody
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 switch fluid
pressure on and off, and to control the hydraulic pressure going to the hydraulic control system.
CP8 VALVE2ND ORIFICE CONTROLVALVE
MODULATOR VALVE
RELIEF VALVE
1-2 SHIFT VALVE
MANUAL VALVE
MAIN VALVEBOOY
SERVO CONTROI-VALVE
Secondary valve Body
The secondary valve body is located on the main valve body, The secondary valve body houses the 2-3 shift valve, the 3-4
shift valve, the 3-4 orifice control valve, the 4th exhaust valve, and the CPC valve'
3.' SHIFT VALVE
.TH EXHAUST VALVE
CPC VAL
(cont'd)
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2.3 SHIFT VALVE
3na ORIFICE CONTROLVALVE
VALVE
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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
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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
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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
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Description
Lock-up System (cont'dl
a
a
Half Lock-up
Lock-up Control Solenoid Valve A: ON
Lock-up Control Solenoid Valve B: Duty Operation
OFF - ON
Linear Solenoid Pressure: Low
The PCM switches solenoid valve A on to release modu-
lator pressure in the left cavity of the lock-up shift valve.
Modulator pressure in the right cavity of the lock-up
shift valve overcomes the spring force, and the lock-up
shift valve is moved to the left side.
Line pressure is then separated into the two passages to
the torque converter; torque converter inner pressure
enters into right side to engage the lock-up clutch, and
torque convener back Dressure enters into left side to
disengage the lock-up clutch.
Back pressure (F2) is regulated by the lock-up control
valve, whereas the position of the lock-up timing valve
is determined by linear solenoid pressure and tension of
the valve spring. Also the position of the lock-up control
valve is determined by the back pressure of the lock-up
control valve. torque converter pressure (regulated by
the torque converter check valve), and modulator pres-
sure (determined by the lock-up control solenoid valve
B). The PCM switches lock-up control solenoid valve B
on and off rapidly (duty operation), under certajn condi-
tions, to regulate back pressur€ (F2) and lock the torque
convertef.
NOTE: When used, "left" and "right" indicates direction
on the hvdraulic circuit.
+ LINEAR SOLENOID PRESSURE
TOFOUE CONVERTER
L(rcK.UP CONTROLSOLENOID VALVE
AB
MODULATORPNESSURE
MAINSHAFT
COUNIERSHAFTRELIEF VALVE
L(rcK-UP TIMINGVALVE
COOLER RELIEF VALVE
ATF STRAINER
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ATF COOLER
ATF PUMP
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Description
Lock-up System (cont'dl
a
a
Decelelation Lock-up
Lock-up Control Solenoid Valve A: ON
Lock-up Control Solenoid Valve B; Duty Operation
OFF - ON
Linear Solenoid Pressure: Low
The PCM switches solenoid valve B on and off rapidly
under certain conditions. The slight lock-up and half
lock-up regions are maintained to lock the torque con-
vener propeny.
NOTE: When used, "left" and "right" indicates direction
on the hydraulic circuit.
+ LINEAR SOLENOID PRESSURE
TOROUE CONVERTER
tMOOULATORPRESSURE
MAINSHAFT
COUNTERSHAFT
SUB.SHAFT
ATF COOLER
RELIEF VALVE
LOCK.UP TIMINGVALVE
COOLER RELIEF VALVE
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ATF STBAINER
ATF PUMP
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PCM Circuit Diagram (A/T Control System)
'97 Model
UNDER.I]OOD FUSAFELAY BOXEATTEFY
_YEL_
T-l ,
TT-l
t_-:
G101
'Fr-r.04
P- r.-or..u L_a TMEALOC(BrK€ru -<< calTFoL
P_ *+rr
F- onmrxCFUISECONTFOLUNITf-"".>
| ["'"]
I l,[-l
III ;,
F_ pw
P_ eLu
F-- enN
UNDER DASN
M 25(7.54)
IGNITONSWITCH UNDEF OASNFUSAFELAYSOX
oowEa-qar. cor.lFo- MooLrE rpcMr F &*1 r*--'l_____O_=_ATP IO! ,ATP . ATD , A-P , A-P , A-PNP lrNo lR 101 103 12 ll
Ar'TGEAR POS]TIONswtcN
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