Cat transmission HONDA CIVIC 1998 6.G Repair Manual

Description
(cont'd)
Gear Sel€stion
The shift lever has six positions: @ pARK, E REVERSE, E NEUTRAL, E DR|VE, g SECOND, and El LOW.
Staning is possible only in E and E positions through the use of a slid6-type, neutrafsafety switch.
Automrtic Transaxle {A/T} Gear Position Indicltor
The A-lT gear position indicator in the instrument panel shows which gear has been selected without having to look downat the console.
PoshionDe3cription
E PARK
E REVEBSE
E NEUTRAL
D DRIVE
E SECOND
E LOW
Front wheels locked; park pawl engaged with the park gear on the driven pulley shaft. The startclutch and the forward clutch released.
Reverse; reverse brake engaged.
Neutral; the start clutch and the forward clutch released.
General driving; the transmission automatically adjusts to keep the engine at the best speed fordriving conditions.
For rapid accelsration at highway speeds; the transmission shifts into a lower range of ratios forbetter acceleration and increased engine braking.
For engine braking and power for climbinO; the transmission shifts into the lowest range of theralros.
l-
14-196

Description
Clutches/Reverse Brake/Planetary Gear/Pulleys
Clulches/Reverse Brake
The CVT uses the hydraulically-actuated clutches and brake to engage or disengage the transmission gears. When
hydraulic pressure is introduced into the clutch drum and the reverse brake piston cavity, the clutch piston and the reverse
brake piston move. This presses the friction djscs and the steel plates together, locking them so they don't slip. Power is
then transmitted through the engaged clutch pack to its hub-mounted gear. and through engaged ring gear to pinion
gears.
Likewise, when the hydraulic pressure is bled from the clutch pack and the reverse brake piston cavity, the piston releases
the friction discs and the steel plates, and they are free to slide past each. This allows the gear to spin independently on its
shaft, transmitting no power.
Start Clutch
The start clutch, which is located at the end of the driven pulley shaft, engages/disengages the secondary drive gear.
The start clutch is supplied hydraulic pressure by its ATF feed pipes within the driven pulley shaft.
Forward Clutch
The forward clutch, which is located at the end of the drive pulley shaft, engages/disengages the sun gear.
The forward clutch is supplied hydraulic pressure by its ATF feed pipe within the drive pulley shaft.
Reverse Brake
The reverse brake, which is located inside the inte.mediate housing around the ring gear, locks the ring gear in E posi-
tion. The reverse brake discs are mounted to the ring gear and the reverse brake plates are mounted to the intermediate
housing. The reverse brake is supplied hydraulic pressure by a circuit connected to the internal hydraulic circuit.
Planetary Gear
The planetary gear consists of a sun gear, a carrier assembly, and a ring gear. The sun gear is connected to the input shaft
with splines. The pinion gears are mounted to the carrier which is mounted to the fo.ward clutch drum. The sun gear
inputs the engine power via the input shaft to the planetary gear, and the carrier outputs the engine power. The ring gear
is only used for switching the rotation direction of the pullev shafts,
In E. E, and E positions (forward range), the pinion gears don't rotate and revolve with the sun gear, so the carrier
rotates. In E] positjon {reverse range), the reverse brake locks the ring gear and the sun gear drives the pinion gears to
rotate. The pinion gears rotate and revolve in the opposite direction from the rotation direction of the sun gear, and the
carrier rotates with pinion gear revolution.
Pulleys
Each pulley consists of a movable face and a fixed face, and the effective pulley .atio changes with engine speed. The
drive pulley and the driven pulley are linked by the steel belt.
To achieve a low pulley ratio, high hydraulic pressure works on the movable face of the driven pulley and reduces the
effective diameter of the drive pulley. and a lower hydraulic pressure works on the movable face of the drive pulley to
eliminate the steel belt slippage. To achieve a high pulley ratio, high hydraulic pressure works on the movable face of the
drive pulley and reduces the eifective diameter of the driven pulley, and a lower hydraulic pressure works on the movable
face of the driven pulley to eliminate the steel belt slippage.
b
14-198

Electronic Control System ('96 - 98 Modelsl
The electronic control system consists of the Transmission control Module (TcM), sensors, three linear solenoids, and an
inhibitor solenoid. Shifting is electronically controlled under all conditions
The TCIM is located below the dashboard, behind the kick panel on the driver's side'
The TcN4 controls the transmission to reduce engine speed and retain the engine's cooling efficiency when the vehicle is
driven with Iull throttle acceleration
lf the vehicle is continuously driven at full throttle acceleration, the TCM regulates the pulley hydraulic pressure to
increase the pulley ratio, which, as the result. reduces the engine speed and retains the designed cooling efficiency After
the vehicle has been driven at a lower engine speed for a while, the TCM increases the pulley ratio to the original ratio.
For smooth starting in the E position, the TcM sends a signal to the EcM to cut off the rvc clutch {if the A!/c is on) and
increases the engine speed to 900 rpm when the transmission is shifted to the E position'
The start clutch functions to make smooth starting possible. To let the start clutch function properly. the TCM regulates
the start clutch hydraulic pressure based on the entine's negative pressure memorized in the E position'
:
:
z
z
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S*ond.ry G..r Sh:ft
(cont'd)
14-203

Electronic Gontrol System ('99 - 00 Modelsl
The electronic controt system conststs of a Powertrain control Module (PCM). sensors, three linear solenoids and an
inhibitor solenoid. shifting is electronically controlled under all conditions A Grade Logic control system to control shift-
ing in E position while the vehicle is ascending or descending a slope'
fn"pCVirlocatedbelowthedashboard,underthekickpanelonthepassenger'sside'
The pCM controls the transmassion to reduce engine speed and retain the engine's cooling efficiency when the vehicle is
driven with full throftle acceleration
lf the vehicle is continuously driven at lull throttle acceleration, the PCM regulates the pulley hydraulic pressure to
increase the pulley ratio which. as the result, reduces the engine speed and retains the designed cooling efficiency After
the vehicle has been driven at a lower engine speed for a while, the PCM increases the pulley ratio to the original ratio'
i"i ".nl",rr starting in the E position, the PcM cuts off the ,Vc clutch (if the A/c is on) and increases the engine speed to
900 rpm when the transmission is shifted to the E position'
The start clutch functions to make smooth starting possible. To let the start clutch function properly, the PcM regulates
the start clutch hydraulic pressure based on the engine's negative pressure memorized in the E position'
FCM
s*o.d.ry G..t Sh.h
(cont'd)
14-205

Description
Hydraulic Flow (cont'd)
lll position, when th€ electronic control system is fauhy.
when the electronic control svstem (linear solenoids and sensors) is faulty, the transmission uses the pitot pipe pressure(PP) to 311o- rh" u"hicle to drive.
when all linear solenoids and sensors are off because of a faulty electronrc control system, clutch reducing pressure (cR)flows to the start clutch control valve, the manual valve, the PH-PL control valve, and the shift control valve. clutch reduc-ing pressure (cR) becomes shift varve pressure (sV) at the shift contror varve, and shift varve pressure {sv) is appried tothe left end of the shift valve and the right end of the shift inhibitor valve. The shift valve moves to the right side. anduncovers the pon that leads high pressure (PH) to the drive pulley and uncovers the po.t tlr"t r""1" ro,,"-pressure (pL) tothe driven pulley At this time, the pulley ratio is high, The shift inhibitor valve moves to the left side, and uncovers theport that leads shift inhibitor pressure (Sll to the pitot lubrication pipe and the pitot regulator valve. tne prtot lubricationpipe discharges fluid inside of the pitot flange, and discharged fluid enters into the pitot pipe and it is applied to the leftend of the pitot regulator valve. The pitot regulator valve moves lo the right side, and uncovers the port that leads pitotregulator pressure (PR) to the shift inhibitor valve. Pitot regulator pressure {pR) becomes start clutch pressure {sc1 at theshift inhibitor valve, and is applied to the stan clutch. The stan clutch rs engaged. The forward clutch pressure (FWD) isapplied to the forward crutch, and the forward crutch is engaged. This alows the vehicre to drive.
NOTE: When used. "|eft" or ,,right', indicates direction on the hydraulic circuit.
14-220
I.

TCM CONNECTOR B (22P}
Terminal NumbelSignalDescriptionMeasuring Conditions/Terminal Voltage
B1SOL INHInhibitor solenoid controlWith inhibitor solenoid ON: Baftery voltage
With inhibitor solenoid OFF: 0 V
82MAP (PB)-M an if old Absol r-rte Pressure IMAP)
sensor signal inPUtWith iqnition switch ON (ll): Approx.2.5 V
With e;gine adling: Approx. 1.0 V (depending on
engine speed)
B3Not used
B4TPS-Throttle Position (TP) sensor signal
input
With ignition switch ON (ll) and throftle fully open:
4.14 - 4.42 VWith ignition switch ON (ll) and throttle fully
closed: 0.44 - 0.56 V
VSSVehicle Speed Sensor (VSS) signal
Inpur
With ignition switch ON (ll) and rotating front
wheelsr 0-5Vcycle
TMBData communication with ECM:
Transmission control data outpUt
With ignilion swltch UN lll): rulslng slgnar
81TMAData communication with EClvl:
PGM Fl control data inPut
With ignition swltch uN {ll,: l-ulslng slgnal
B8NDN SGDriven pulley speed sensor ground
B9NDNDriven pulley speed sensor signal
input
ln other thTnE and E position: Pulsing signal
810NDRDrive pulley speed sensor signal
Input
-tn ottrer ttran E ana E position: Pulsing signal
811Not used
812STOP SWBrake switch signal inPutWith brake pedal depressed: Battery voltage
With brake pedal released: 0 V
813DIAG-H(TXD/RXD)Data communication:Diagnostic trouble code outPut
Wittr ignitio.r s*itct' ON (ll): Approx 5.0 V
814Se-ice ctrect signatWith ignition switch ON (ll) and service check
connector oPen: APProx.5 V
With iqnition switch ON (ll) and service check
"onn"itot. connect"d with special tool: 0 V
Secondary gear shaft speed sensor
signal input
Depending on vehicle speed: Pulsing signal
When vehicle is stoPped: 0 V815VEL
816VEL SGSecondary gear shaft speed sensorgrouno
817NDR SGDrive pulley speed sensor ground
818HBRK SWParking brake switch signal inPutWith parking brake lever pulledr 0 V
With parking brake lever released: Battery voltage
819Not used
B20VREF+5 V relerenceWith ignition switch ON (ll): Approx 5 V
821Not used
Not used

Troubleshooting Flowchart - Vehicle Speed Sensor (VSS)
NOTE: Record all freeze data before you troubleshoot'
Po$rible Ctuse
. Disconnected vehicle speed
sensor (VSS) connectol. Short or open in VSS wire' Faulty VSS
@. Make sure lifts, iacks, and sal€tY stands are placed properly lsoe section 1)'
. Set the parking brake securelv, and block the rear wheels'
. iacr upile rront or the vehicle, and support it with safety st'nds'
TCM CONNECTORS
Wire side of female terminals
. OBD ll Scan Tool indicates Code
P1791.. Setf-diagno3is E indicato. light
blinks tour times.
Refer to seclion 23 for vehicle
soeed sensor IVSSI test
Check the VSS Voltage:
1. Raise the vehicle2. Shift the transmission to lEposrtlon.3. Disconnect the A (26P) and B(22P) connectors from the
TCM.4. Turn the ignition switch ON {ll).
5. Rotate the front wheel and
check for the voltage between
the 85 and 413 or A26 termi-
nals. Block the other wheel so
at does not turn
Check for oP€n in the wire
between the 85 terminal and the
vehicle speed sensor {VSS}. lf
wire is OK, check the vSS (see
soction 23).
Does0Vandapprox 5 V or more
appear alternatelY?
Check for loos€ TCM connedors
lI nec€ssary, substitute a known'
good TCM and recheck.
14-243

Start Clutch Control@
T
Start Clutch Calibration Procedure
NOTE: When the following parts are replaced, the TCM
must memorize the feedback signal for the start clutch
control.
. TCM
. Transmissionassembly
. Stan clutch assembly
. Lower valve bodv assembly
. Engine assembly or overhaul
'96 Model Only
CAUTION: Do not uso this procsdure on'97 - (X) mod-
els or you will damage the transmission. On '97 - 00
models, the TCM or PCM memorizes ths loodback sig'
nals when you drive the vehicle.
1. Engage the parking brake, and block the front
wheels securely.
2. Connect the SCS service connector to the Service
Check Connector as shown. (The Service Check
connector (2P) is located under the dash on the
passenger's side of the vehicle.)
CONNECTOR07PAZ - lDl01(xt
Start the engine, and warm it up to normal operat-
ing temperature (the radiator fan comes on twice).
Fully depress the brake pedal and accelerator for 20
seconds in the E] position.
rl ,
CONNECTOR I2PI
14-293
7.
Shift into E o|. E position. To store the engine
negative pressure in memory. Iet the engine idle in
E or E position for one minute under the follow-
ing conditions:
. With the brake pedal depressed,
. with the y'\/c switch oFF.
. With the combination light switch OFF.
. With the heater fan switch OFF.
. Turn OFF all other electrical systems
NOTE: Start step 5 within 60 seconds after the radi-
ator fan goes off.
Shift into E position, and let the engine idle for two
minutes to store the feedback signal in memory
under the same conditions as in step 5.
Connect the Honda PGM Tester. Check that the TCM
has completed the start clutch calibration.
NOTE:
. The TCM will not store the feedback signal when
the CVT fluid temperature is below 40"C (104'F)
even if the engine coolant temperature reaches
the normal operating temperature.
. Repeat these procedures until the start clutch
calibration is completed-
Disconnect the SCS service connector from the
Service Check Connector.
'97 - 00 Models
The TCM ('97 - 98 models) and PCM ('99 - 00 models)
memorize the feedback signal when you drive the
vehicle as follows:
. After warming up the engine (the radiator fan
comes onl.
. Shift into E position.
. Turn OFF all electrical systems,
. Drive the vehicle up to the speed 37 mph (60
km/h).
. After the speed reaches 37 mph (60 km/h),
release the accelerator for 5 seconds.

Stall Speed
Test
CAUTION:
. To prevent transmission damage, do not test stall sp€€d for mole than 10 seconds at a time.
. Do not shift the lsver whils raising the engine speod.
. Be sure lo remove the pressure gauge before tosting stall speed.
. Stall speed tssts should be used tor diagnostic purposes only,
1. Engage the parking brake, and block the tront wheels.
2. Connect a tachometer to the engine, and stan the engine.
3. Make sure the A/C switch is OFF.
4. After the engine has warmed up to normal operating temperature (the radiator fan comes on), shift into E position.
5. Fully depress the brake pedal and accelerator for 6 to 8 seconds, and note engine speed,
6. Allow two minutes for cooling, then repeat the test in E, E, and E positions.
Stall Speed BPM in E poshion:
Specification: 2,500 rpm
Servic€ Limit: 2,350 - 2.650 rpm
Stall Speed RPM in E, E and E positions:
Specitication: 3,000 rpm
Service Limit: 2,800 - 3,100 rpm
TROUBLEPROBABLE CAUSE
Stall rpm high in @. p. [, and @ positionsLow fluid level or ATF pump output
Clogged ATF strain€r
PH regulator valve stuck closed
Slippage of forward clutch
Faulty start clutch
Stall rpm high in E position. Slippage of reverse brake. Faulty start clutch
Stall rpm low in E, P, [, and @ positionsEngine output low
Faulty stan clutch
Stuck shift valve
14-294

1.
Start the engine.
Shift to the respective shift lever positions in the table, and measure the following pressures at 1'500 rpm'
. Forward Clutch Pressure
. Reverse Brake Pressure
. Drive Pulley Pressure
. Driven Pulley Pressure
8. Shift to E posltion, and measure the lubrication pressure at 3,000 rpm'
Disconnect the special tool after pressure testlng
Install the sealing boits in the jnspection holes with new sealing washers, and tighten the bolts to the specified
toroue.
TOROUE: 18 N.m {1.8 kgf'm, 13 lbf'ft}
CAUTION: Keep all foreign particles out of the transmission'
9.
10.
PBESSURESHIFT LEVER
POSmONSYMP{OMPROBABLE CAUSE
FLUID PRESSURE
Standard/Ssrvice Limit
Forwa rd
Clutch
ENo or low for-
ward clutch
pressure
Forward Clutch1.4 - 1.75 MPa
(14.3 - 17.8 kgtcm', 203 - 253 Psi)
Reverse
Brake
tsNo or low
reverse brake
pressure
Reverse Brake1.4 - 1.75 MPa
(14.3 - '17.8 kg7cm', 203 - 253 Psi)
Drive
Pulley
NNo or low
drive pulley
pressure
ATF pump, PH reg-
ulator valve, PL
regulator valve,
Shift valve
0.2 - 0.7 MPa
(2 - 7.1 kgflcm', 28 - 101 Psi)
Drive pulley
pressure roo
high
PH regulator valve,
PL regulator valve,
Shift valve. Shift
control linear
solenoid
Driven
Pulley
No or low
driven pulley
pressure
ATF pump, PH reg-
ulator valve, Shift
valve, Shift control
linear solenoid
1.5 - 2.3 MPa
(15.3 - 23.5 kg?cm', 218 - 334 Psi)
Driven pulley
pressure too
h igh
PH regulator valve
LubricationNo or low
lubrication
pressure
ATF pump,
Lubrication valve
Above 0.2 MPa
(Above 2 kgf/cm'. 30 Psi)
14-301