1999 HONDA CIVIC pan

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

Electronic Control SYstem
The electronac controt system consrsts of a Powertrain control Module (PcM), sensors, a Iinear solenoid and four solenoid
valves, shifting and lock-up are electronically controlled for comfortable driving under all conditions The PCM is located
below the dashboard, under the front lower panel on the passenger's side
PGM-FIControl Sy3tem
A/T Control SYstom
Shift Control
Lock-uD Control
14-13

Troubleshooting Procedures
1.
2.
(cont'dl
Remove the kick panel on the passenger's side {see section 20}.
Remove the PCM. and turn the PCM over.
Inspect the circuit on the PCM according to the troubleshooting flowchart with the spocial tools and a digital multime-ter as shown.
How lo Use tha Backprobe Set
Connect the backprobe adapters to the stacking patch cords, and connect the cords to a multimeter. Using the wireinsulation as a guide for the contoured tip of the backprobe adapter, gently slide the tip into the connector from thewire side until it comes in contact with the terminal end ofthe wire.
BACKPROSE
BACKPROBE SET07saz - (xtl(xtoA
{two required)
DIGITAL MULNMEIER(Comm€rcially 6vailabl€l-aHM-32-003
t..
14-50
or equival€nt

From page 14-56
Ch6ck Lock-up Control Solenoid
Valve A tor a Short Cilcuiti
1. Disconnect the 2P connector
lrom the lock-up control sole-
noid valve assemblY.2. Check for continuity between
the 85 and Ag or A22 termi-
nats.
Ropair 3hort to giound in iha wila
b.twoqn th6 85 terminrl rnd tho
locl-up control 3olanoid valvo A.
Mo..ura Lock-up Control Sole'
noid Velve A Reri3tanc. at tho
Solenoid Conn6cto.:Measure the resistance betweenthe No. 2 terminal of the lock-up
control solenoid connector and
body ground.
Chock for opan in tha wit.
ba(w.an tha 85 torminll lnd the
lock-uo control lolanoid vtlYa A.ls the resistance 12 _ 25 O?
Roplsce tho lock"up cont.ol 3ol€_
noid vllvo arsembly.
PCM CONNECIOBS
Wire side of lem6leterminals
LOCK.UP CONTROLSOrINOID CONNECTOR
YEL
Teaminal side of malo terminals
lml-,f
(o)
I
14-57

Check the G.ound Circuit:Check for continuity between theA9 and A10 terminals.
. Rapair opan in the wirobotweon th6 tormin.b Ag rndA10 and G101.. Raprir looc€ iunction connrc{or.. R.p.ir poor ground {G101}.
Chock tor 100!6 PCM connectors.ll nocessary, substituto a known-good PCM and r6ch6ck.
Ftom page 14-72
PCM CONNECTOR A I32P}
Wiro side of t6male terminals
14-73

From page 14-76
BRN/BLK
BRN/BLK'96: BLU/RED,97, '98: GRN/BLK
Measure Powor Supply CilcuitVoltage:1. Turn the ignition switch ON (ll).
2. Measure the voltage betweenterminals A9 and A11 andbetween terminals A22 and424.
RGpair opon or short in the wire
boiween the A11 andlot Ml lor'
minals, the PGM-Fl m.in rel.Y,end the tu36 box.
Mo.sure D4 IND Voltago:1. Turn the ignition switch OFF.2. Connect the A {32P} connector
to the PCM.3. Connecl a digital multitester
to the B13 and Ag or A22 ter-minals,4. Turn the ignition switch ON (ll)
and make sure that the voltageis available for two seconds.
Chack tor opan in thc witabctwoon tha 813 larminal andth. gauge ar!.mbly. lf wi.c i!OK, chock for . frulty E indica-tor light bulb or a l.uhy g.ug.
a.!.mbly printod circuit bolrd.
Chock for loose PCM connoctort.Chock tho A/T gGat polition
switch. lI n6ca$sry, substitute aknown-good PCM and rochock.
PCM CONNECTOR A I32PI
Wire side of {emale terminals
14-77