1998 HONDA CIVIC Clutch

\
Lock-up System
Lock-up Clutch
1. Ooeration (clutch onl
with the lock-up clutch on, the fluid in the chamber between the torque converter cover and the lock-up piston is drained
off, 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 convefter cover. The effect is to bypass the converter, thereby placing the vehicle in direct drive
LOCK.UP PISTONDAMPER SPRING
The power flows by way ot:
Engine
{
Drive plate
i
Torque converter cover
I
Lock-up piston
Damper spring
I
Turbine
Mainshaft
ODeration {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 from
the converter cover, and the torque converter lock-up is releassd.
Engine
t
Drive plate
I
Torque convener cover
{
Pump
I
Turbine
Mainshaft
TOROUECOVER
(cont'd)
COI{VERTER
\
TURBNE
MAINSHAFT
14-33

Description
Lock-up System (cont'd)
TOROUE CONVERTER
In B.rl position, in 3rd and 4th, and lDl_- position in 3rd.pressurized fluid is drajned from the back of the torqueconverter through a fluid passage. causing the lock-uppiston to be held against the torque convener cover. Asthis takes place, the mainshaft rotates at the same speedas the engine crankshaft, Together with the hydrauliccontrol, the PCM optimized the timing of the lock_upsystem. Under certain conditions, the lock_up clutch isapplied during deceleration, in 3rd and 4th gear.
The lock-up system controls the range of lock_up accord_ing to lock-up control solenoid valves A and B. and thelinear solenoid. When lock-up control solenoid valves Aand B activate, modulator pressure changes. Lock_upcontrol solenoid valves A and B and the linear solenoidare mounted on the outside of the torque converterhousing. and are controlled by the pclvl.
Lock-up Conditions/Lock-up Control Solenoid Valves/Linear Solenoid Pressure
MODULATOR PRESSURE
.-- LINEAR SOLENOID PRESSURE
LOCK.UP CONTROL. VALVE
LOCK.UP CONTROLSOLENOID VALVELock-up
Conditions
Lock-up Control
Solenoid ValveLineal
Solenoid
PressureAB
Lock-up OFFOFFOFFHig h
Lock-up. HalfONDuty operation
OFF - ON
Lock-up. FullONONHigh
Lock-up
during
decelerationONDuty operation
OFF * ONLowTOROUE CONVERTERCHECI( VALVE
RELIEF VAI-VE
LOCK.UP TIMINGVALVE
^ r______rr r cooLER RELTEF VALVE
t'-
14-34
ATF PUMP

I
TOROUE CONVERTER
No Lock-up
. Lock-up Control Solenoid Valve A: OFF
. Lock-up Control Solenoid Valve B: OFF
. Linear Solenoid Pressure: High
The pressurized fluid regulated by the modulator works
on both ends of the lock-up shift valve. Under this condi-
tion, the pressures working on both ends of the lock-up
shift valve are equal, the lock-up shift valve is moved to
the right side by the tension of the valve spring alone.
The fluid from the ATF pump will flow through the left
side of the lock-up clutch to the torque convener; that is,
the lock-up clutch is in OFF condition.
NOTE: When used, "left" or "right" indicates direction
on the hydraulic circuit.
MOOULATOR PRESSURE
LINEAR SOLENOIO PRESSURE
(cont'd)
LOCK.UP CONTROLSOLENOID VALVE
RELIEF VALVE
LOCK-UP TIMINGVALVE
9 L ] I COOLER RELIEF VALVE
ATF PUMP
14-35

Description
Lock-up System (cont'dl
TOROUE CONVERTER
Half Lock-up
. Lock-up Control Solenoid Valve A: ONLock-up Control Solenoid Valve 8: Duty Operation
OFF - ONLinear Solenoid Pressure: Low
The PCM switches the solenoid valve A on to release themodulator pressure in the left cavity of the lock_up shiftvalve. The modulator pressure in the right cavity of thelock-up shift valve overcomes the spring force; thus thelock-up shift valve is moved to the left side.The line pressure is then separated into the two pas-sages to the torque converter:
Torque Converter Inner pressure: enters into rightsade to engage lock-up clutch
Torque Converter Back pressure: enters into left sideto diseogage lock-up clutchThe back pressure (F2) is regulated by the lock-up con-trol valve, whereas the position of the lock-up timingvalve is determined by the linear solenoid Dressure andtension of the valve spring. Also the position of the lock_up control valve is determined by the back pressure ofthe lock-up control valve, torque converter pressure reg_ulated by the torque converter check valve, and modula_tor pressure determined by the lock-up control solenoidvalve B. The PCM switches the lock-up control solenoidvalve B on and off rapidly {duty operation} under certainconditions to regulate the back pressure (F2) to lock thetorque convener properly.
NOTE: When used, "left" or "right" indicates directionon the hvdraulic circuit.
MODULATOR PRESSURE
LINEAR SOLENOTD PRESSURE
LOCK.UP CONTROLVALVE
LOCK.UP CONTROLSOI.TNOID VALVE
A8
TOROUE CONVERTERCHECK VAI-VE
RELIEF VALVE
LOCK-UP TIMINGVALVE
^ L____J'r cooLER RELTEF valvE
14-36
ATF PUMP

TOROUE CONVERTER
Full Lock-up
. Lock-up Control Solenoid Valve A: ON
. Lock-up Control Solenoid Valve B: ON
o Linear Solenoid Pressure: High
When the vehicle speed further increases. the linear
solenoid pressure is increased to high in accordance
with the linear solenoid controlled bv the PCM.
The lock-up timing valve overcomes the spring force
and moves to the left side. Also, this valve closes the
fluid port leading to the left side of the lock-up control
Under this condition. the modulator pressure in the left
side of the lock-up control valve had already been
released by the lock-up control solenoid valve B; the
lock-up control valve js moved to the left side. As this
takes place, the torque converter back pressure is
released fully. causing the lock-up clutch to be engaged
fully.
NOTE: When used, "|eft" or "right" indicates direction
on the hvdraulic circuit.
MODULATOR PRESSURE
LINEAR SOLENOIO PRESSURE
{cont'd)
LOCK.UP CONTROLSOLENOID VALVE
RELIEF VALVE
LOCK.UP TIMINGVALVE
'r ,-.r' cooLER RELTEF vALvE
ATF PUMP
14-37

Troubleshooting Flowchart - Shift Control System
NOTE: Record all freeze data before vou troubleshoot.
Possible Cause
Faulty shift control system
. OBD ll Scan Tool indicates CodeP0730.. Sell-diagnosis E indicator
light indicates Code ill.
Check tor Another CoderCheck whether the OBD ll scantool or the E, indicator lightindicate another code.
Perlorm ths TroubleshoolingFlowch.rt for the indic.t.dCode(sl. Recheck tor code m730
l4'l I atter troubleshooting.
Does the oBD ll scan tool orthe E indicato'. tight indicate another code?
Test lst, 2nd, 3rd and 4th Clutch
Pressure:Measure the 1st, 2nd, 3rd and 4th
clutch pressure (see page 14119
thru 14-121).
Ropair the hydrlulic systom !snecessary {see page 14-1 19 and11-1211.
ls each clutch pressure within
the service limit?
Replace Shift Control Solenoidvalve Assembly, Linear SolenoidAssambly and Rechock:1. Replace the shift controlsolenoid valve A'/B assembly(see page 14-106).2. Replace the linear solenoidassembly lsee page 14 108).3. Turn the ignition switch OFFand reset the PCM memory byremoving the EACK UP (7.5 A)tuse in the under hood fuse/relay box for more than l0
seconds,4. Drive the vehicle at over 12mph (20 km/h) in 1st, 2nd,3rd
and 4th gear for more than 30seconds at P1 position.
5. Recheck tor code P0730 (41).
Does the OBD ll scan tool orthe Ed indicator tight indi
cate code P0730 {41)?
The swt6m is OK et this time.
NOTE: Do not continue with this troubleshooting until the causes ot any
other DTCS have been corrected.

Electrical Troubleshooting ('99 - 00 Modelsl
Troubleshooting Flowchart - Shift Control System
NOTE: Record allfreeze data before you troubleshoot.
Po33ibl. Crus6
Frulty 3hift control ryrtom
. OBD ll Scan Tool indicrtd Codem730.. Self-dirgnosis E indicatorlight indicst€. Codo 41.
Check for Anoth€. Code:Check whether the OBD ll scantool or the E indicator lightindicate another code.
Prrf orm tho Troublc!hootingFlowch.rt for th. indicrt.dCod.l3l. R.ch.ck tor cod. m730141| .tt r troubldhootlng.
Doesthe OBD llscan tool orthe E indicator light indi-cate another code?
Test 13t, 2nd, 3rd .nd 4th ClutchPrglture:Measure the 1st, 2nd,3rd and 4thclutch pressure (see page 14-119thru 14 121).
R.prir tho hydrlulic ayrtam aan.c.3t..y lr.o p!9. lil-119 rnd1+1211.
ls each clutch pressure withinthe service limit?
Roplace Shift Control SolenoidValve Asembly. Linoar Sol.noidAssembly .nd Recheck:1. Replace the shift controlsolenoid valve A/B assembly(see page 14-106).2. Replace the linear solenoidassembly {see page 14-108}.3. Turn the ignition switch OFFand reset the PCM memory byremoving the BACK UP (7.5 A)fuse in the under-hood fuse/relay box for more than 10seconds,4. Drive the vehicle at over 12mph (20 kn/h) in 1st, 2nd, 3rdand 4th gear lo. more than 30seconds at lPll position.5. Recheck for code P0730 (41).
Doesthe OBD Ilscan tool orthe E ;ndicator light indi-cate code P0730 (41)?Th. sFtcm b OK .t this time.
NOTE: Do not continue with this lroubleshooting until the causes ot anyother OTCS have beon corrected.
I
14-100

Symptom-to-Component Chart
Hydraulic System
SYMPTOMCheck these items on the Check lhese lems on
PROBABLE CAUSE List the NOTES LIst
Engine runs, but vehicle does not move in any gear.1.2,3,5,6,7.36,38 K, L, R, S
Vehicle moves in E, E, but not in lrl, pr-, position.6, 8, 9, 10, 30, 54c,M,o
Vehicle moves in Dl, E, El,lut not in E position.6,11,12.24C,L
Vehicle moves in -o1], @, @, Uut not in E position.4, 6, 14, 15c,L,o
Vehicle moves in E position.10, 12, 13,14, 16, 29, 33, 34, 35C,D
Excessive idle vibration.1.2, 19,32,36, 45, 41, 4a
Poor acceleration; flares on starting otf in E, [Dl] position
Stall rpm hiqh in !!1, p!1, E position.1,2,3,6,34, 41K,L,R
stall rom hioh in D.r, lD,l oosition.6. 8. 10C,D
5t"[ rprn rsn ^ a"t"t-at6,12C,D
14N
11 , 32. 45, 41 , 48
No shift19,20, 40, 48, 49G,L
Fails to shift in 81, pll position; from lst to 3rd gear22, 49
Fails to shift in 03, D. oosition; from lstto4th qear22.23, 48
Erratic upshifting.
1'2 upshift, 2-3 upshift, 3-4 upshift
1-2 upshift
3'4 upshift
58
21, 48
22, t9
23,la
Harsh upshift {1 2).12, 19, 20, 29. 50, 51, 57. 54
Harsh upshift (2'3).13, 19, 20, 24, 27 , 29, 50. 51 , 51 , 58C,D,E,H,L
Harsh upshift (3'4).14, 19, 20, 25, 28, 29. 50, 51 , 51 , IC, D, E, I,L
Harsh downshift (2-1)19, 20. 24, 43, 54, 57 , 58o
Harsh downshift (3-2).12, 19, 20,25, 43, 55, 57,5AC,D,E,H
Harsh downshift (4-3).13, 19, 20, 26, 43, 56, 57, 58C, D, E, I
Flares on 2-3 upshift.13, 19,20,24.21,51FI
Flares on 3-4 upshift.14, 19 . 20, 25. 24, 51E,L,N
Excessive shock on 2-3 uPshift.13. 19, 20, 24, 27 . 43. 50. 51 , 58E,L,N
Excessive shock on 3-4 uPshift.14, 19, 20, 25. 2A, 8, 50, 51 , 58E,L,N
Late shift from El position to Lq! or &l position.10, 30
Late shift from E position to E position.4, 14, 21,53o
Noise from transmission in all shift lever positions2,31K,L,O
Vehicle does not acceletate more than 31 mph {50 km/h)17
shift lever does not operate smoothly.6, 39P
Fails to shift; stuck in 4th gear.19, 48, 49
Transmission will not shift into park in [a] position6, 18, 39
Stall rpm high; all clutch pressures are in specification.41D,K,O
Lock up clutch does not disengage.19, 44, 45, 46. 41,50,51.54
Lock up clutch does not operate smoothly.19, 41, 44, 45, 46, 47, 50, 51, 58L
Lock-up clutch does not engage.19, 41, 4t, 15, 46, 41 ,50, 51, 57, 58FI
Vibration in all positions
(cont'd)