HONDA CIVIC 1999 6.G Workshop Manual

Description
The automatic transmission is a 3-element torque converter and a dual-shaft electronically controlled unit which provides
4 soeeds forward and 1 reverse.
Torque Convertel, Geats, and Clutches
The torque converter consists of a pump, turbine and stator, assembled in a single unit. They are connected to the engine
crankshaft so they turn together as a unit as the engine turns. Around the outside of the torque converter is a ring gear
which meshes with the starter pinion when the engine is being started. The entire torque converter assembly seryes as a
flywheel while transmiuing power to the transmission mainshaft.
The transmission has two parallel shafts: the mainshaft and the countershaft. The mainshaft is in Iine with the engine
crankshaft. The mainshaft includes the 1st, 2nd and 4th clutches, gears tor 2nd, 4th, reverse and lst (3rd gear is integral
with the mainshaft, while the reverse gear is integral with the 4th gear). The countershaft includes the 3rd clutch, and
gears for 3rd,2nd, 4th, reverse. 1st and park. The gears on the mainshaft are in constant mesh with those on the counter-
shaft. When certain combinations of gears in transmission are engaged by clutches. power is transmitted from the main-
shaft to the countershaft to provide E, ld, E, and E positions.
Electronic Control
The electronic control svstem consists of the Powertrain Control Module {PCM), sensors, a linear solenoid and four
solenojd valves. Shifting and lock-up are electronically controlled for comtonable driving under all conditions. The PCM is
located below the dashboard, under the front lower panel on the passenger's side
Hydraulic Control
The valve bodies include the main vatve body, the secondary valve body, the regulator valve body, the servo body and the
lock-up valve body through the respective separator plates, They are bolted on the torque converter housang
The main valve body contains the manual valve, the 1-2 shift valve. the 2nd orifice control valve, the CPB {Clutch Pressure
Back-up) valve, the modulator valve. the servo control valve, the relief valve, and ATF pump gears The secondary valve
body contains the 2-3 shift valve. the 3-4 shift valve, the 3-4 orifice control valve, the 4th exhaust valve and the CPC (Clutch
pressure Control) valve. The regulator valve body contains the pressure regulator valve, the torque converter check valve,
the cooler relief valve, and the lock-up control valve. The servo body contains the servo valve which is integrated with the
reverse shift fork, and the accumulators. The lock-up valve body contains the lock-up shift valve and the lock-up timing
valve. The linear solenoid and the shift control solenoid valve Ay'B are bolted on the outside of the transmission housing,
and the lock-up control solenoid valve Ay'B is bolted on the outside of the torque converter housing. Fluid from regulator
passes through the manual valve to the various control valves. The clutches receive fluid from their respective teed pipes
or internal hydraulic circuit.
Shift Control Mechanism
Input from various sensors located throughout the car determines which shift control solenoid valve the PCM will activate
Activating a shift control solenoid valve changes modulator pressure, causing a shift valve to move. This pressurizes a line
to one of the clutches, engaging that clutch and its corresponding gear, The shift control solenoid valves A and B are con-
trolled by the PCM.
Lock-up Mechanism
In ,Dt1 position, in 3rd and 4th. and in E position in 3rd, pressurized fluid is drained from the back of the torque converter
through a fluid passage, causing the lock-up piston to be held against the torque converter cover. As this takes place, the
mainshaft rotates at the same as the engine crankshaft. Together with hydraulic control, the PCM optimizes the timing of
the lock-up mechanism. The lock-up valves control the range of lock-up according to lock-up control solenoid valves A and
B, and linear solenoid. When lock-up control solenoid valves A and B activate, the modulator pressure changes The lock-
up control solenoid valves A and B and the linear solenoid are controlled by the PCM.
(cont'd)
14-3

Description
(cont'dl
Gear Selection
The shift lever has six positions: E PARK. E REVERSE, N NEUTRAL, E 1st through 4th gear ranges, E 1st through 3rdgear ranges, @ 2nd gear.
Starting is possible only in E and E positions through the use of a slide-type, neutral-safety switch.
Automatic Transaxle (A/f, Gear Position Indicator
The Ay'T gear position indicator in the instrument panel shows which gear has been selected without having to look downat the console.
Clutch€s
The four-speed automatic transmission uses hydraulically-actuated clutches to engage or disengage the transmission gears.When hydraulic pressure is introduced into the clutch drum, the clutch piston moves. This presses the friction discs andsteel plates together, locking them so they don't slip. Power is then transmitted through the engaged clutch pack to itshub-mounted gear. Likewise, when the hydraulic pressure is bled from the clutch pack, the piston releases the friction discsand the steel plates, and they are free to slide past each other. This allows the gear to spin independently on its shaft,transmitting no power.
lst Clutch
The 1st clutch engages/disengages 1st gear, and is located at the end of the mainshaft, just behind the right sroe cover.The 1st clutch is supplied hydraulic pressure by its ATF feed pipe within the mainshaft.
2nd Clulch
The 2nd clutch engagegdisengages 2nd gear, and is located at the middle of the mainshaft. The 2nd clutch is joined
back-to-back to the 4th clutch. The 2nd clutch is supplied hydraulic pressure through the mainshaft by a circutr connect-ed to the internal hvdraulic circuit,
3rd Clutch
The 3rd clutch engages/disengages 3rd gear, and is located at the end of the countershaft. The 3rd clutch is suooliedhydraulic pressure by its ATF feed pipe within the countershaft.
ilth Clutch
The 4th clutch engages/disengages 4th gear, as well as reverse gear, and is located at the middle of the mainshaft. The4th clutch is joined back-to-back to the 2nd clutch. The 4th clutch is supplied hydraulic pressure by its ATF feed pipewith in the mainshaft.
\-a
PositionDe3cription
E PARK
E REVERSE
N NEUTRAL
E DRIVE
{1st through 4th)
Ei DRtvE('lst through 3rd)
B SECOND
Front wheels locked; park pawl engaged with pa* on countershaft. All clutches released.
Reverse; reverse selector engaged with countershaft reverse gear and 4th clutch locked.
All clutches released.
General driving; starts off in 1st, shifts automatically to 2nd, 3rd, then 4th, depending on vehiclespeed and throttle position. Downshift through 3rd, 2nd and 1st on deceleration to stop. The lock-upmechanism comes into operation in @ position in 3rd and 4th gear.
Use for rapid acceleration at highway speeds and general driving; up-hill and down,hill dfiving; stansotf in 1st, shifts automatically to 2nd, then 3rd, depending on vehicle speed and throttle position.
Downshifts through 2nd to lst on deceleration to stop. The lock-up mechanism comes into operationin 3rd gear,
Use for engine braking or better traction starting off on loose or slippery surfaces; stays in 2ndgear, does not shift up and down.
14-4

One-way Clulch
The one-way clutch is positioned between the countershaft 1st gear and the park gea., with the park gear splined to the counter-
shatt, The 1st gear provides the outer race surface, and the park gear provides the inner race surface. The one-way clutch
locks up when power is transmitted from the mainshaft 1st gear to thetountershaft 1st gear. The lst clutch and gears
remain engaged in the 1st, 2nd. 3rd, and 4th gear ranges in the p!1, p! or L?l position.
However, the one-way clutch disengages when the 2nd, 3rd, or 4th clutches/gears are applied in the E, E or @ position.
This is because the increased rotational speed of the gears on the countershaft overrides the locking "speed range" of the
one-way clutch. Thereafter, the one-way clutch free-wheels with the 1st clutch still engaged.
zNO CLUTCH ,lTH CLUTCH
1ST CLUTCH
MAINSHAFT
COUNTERSHAFT
ONE.WAY CLUTCH
INSIDE OF ONE.WAYCLUTCHSplaned with countershaft
disengage outsideand inside oI the
3RO CLUTCH
OUTSIDE OF ONE.WAYCLUTCH
PANK GEAR
The sprags engage/
OVER-RIDINGLOCKING SPEED CONDITIONLOCKING CONDITION
14-5

Description
Power Flow
O: Operates, x: Doesn't operate.*1: Although the 1st clutch engages, driving power is not transmitted as the one-way clutch slips.*2: The one-way clutch engages when accelerating, and slips when decelerating.
\ARTPOSMON\
TOROUE1ST GEAR
CLUTCH
2ND GEAR
2ND
CLUTCH
3RD GEAR
3RD
CLUTCH
4THREVERSE
GEAR
PARK
GEARCONVERTERCLUTCH
Eoo
Eooo
Eo
D]
1SToo*,
2NDoo*,o
3RDoo*1o
4THoo*1oo
tr
oO*r
2NDoo+ro
3RDoo*1o
Eoo*1o
14-6

lXl Position
Hydraulic pressure is not applied to the clutches. Power is not transmifted to the countershaft.
E Position
Hydraulic pressure is not applied to the clutches. Power is not transmitted to the countershaft.
The countershaft is locked by the park pawl interlocking the park gear.
TOROUE CONVERTER
rST CLUTCH
COUNTERSHAFT
FINAL DRIVE
3RD CLUTCH
14-7

Description
Power Flow (cont'dl
lst Gesr (E or @ position)
In lE or E position, the optimum gear is automatically selected from 1st,2nd,3rd and 4th gears, according to conditionssuch as the balance between throttle opening (engine load) and vehicle speed.
1. Hydraulic pressure is applied to the 1st clutch, which rotates together with the mainshaft, causing the mainshaft 1stgear to rotate.
Power is transmitted to the countershaft 1st gear, which drives the countershaft via the one-way clutch.
Power is transmitted to the final drive gear, which drives the final driven gear.
TOROUE CONVERTER
MAINSHAFT 1ST GEAR
lST CLUTCH
MAINSHAFT
AY CLUTCH
FINAL DRIVE GEAR
PARK GEAR
L
COUNTERSHAFT1ST GEAR
14-8

2nd Gear {8, E or E position)
E Position is provided to drive only 2nd gear.
1. Hydraulic pressure is applied to the 2nd clutch on the mainshaft, and power is transmifted via the 2nd clutch to the
mainshaft 2nd gear.
2, Powet transmitted to the mainshaft 2nd gear is conveyed via tho countorshaft 2nd gear, which drivos the counter-
shaft.
3. Power is transmined to the final drivB gear, which drives the final driven ge8r.
NOTE: Hydraulic pressure is also applied to the 1st clutch, but since the rotation speed of ths 2nd gear excaads that
of lst gear, power from 'lst gear is cut off at the one-way clutch.
TOROUE CONVERTER
2ND CLUTCH
MAII'ISHAFT
COUNTEBSHAFT 2I{D GEAR
(cont'd)
14-9

Description
Power Flow (cont'dl
3rd Gear (bl or bd positionl
1. Hydraulic pressure is applied to the 3rd clutch. Power from the mainshaft 3rd gear is transmitted to the countershaft3rd gear.
2. Power is transmitted to the final drive gear, which drives the tinal driven gear.
NOTE: Hydraulic pressure is also applied to the 1st clutch, but since the rotation speed of 3rd gear exceeds that of 1stgear, power from lst gear is cut off at the one-way clutch.
TOROUE CONVERTER
MAINSHAFT 3RD GEAR
MAINSHAFT
COUNTERSHAFT
3RD GEAB
3RD CLUTCH
14-10
DRIVEN GEAR

4th cear lE position)
1. Hydraulic pressure is applied to the 4th clutch, which rotates together with the mainshaft, causing the mainshaft 4th
gear to rotate.
2. Power is transmitted to the countershaft 4th gear' which drives the countershaft'
3. Power is transmitted to the final drive gear, which drives the final driven gear'
NOTE: Hvdraulic pressure is also applied to the lst clutch, but since the rotation speed of 4th gear exceeds that of 1st
gear, power from 1st gear is cut off at the one-way clutch
TOROUE
MAINSHAFT 4TH GEAR
COUNTERSHAFT
FINAL ORIVEN GEAR
14-11

Description
Power Flow (cont'd)
El Po3ition
1, Hydraulic pressure is switched by the manual valve to the servo valve, which moves the reverse shift fork to thereverse position. The reverse shift fork engages with the reverse selector, reverse selector hub, and the countershaftreverse gear.
Hydraulic pressure is also applied to the 4th clutch. Power is transmitt€d from the mainshaft reverse gear via thereverse idler gear to the countershaft reverse gear.
The rotation direction of the countershaft reverse gear is changed via the reverse idler gear,
Power is transmitted to the final drive gear, which drives the final driven gear.
TOROUE
MAINSHAFT
COU TERSHAFT
REVERSE SELECTORHUBREVERSE SETICTOR
REVERSE SHIFTFORK
REVERSE IDLER
14-12
FINAL ON|VEN GEAR