1996 HONDA CIVIC PCM

Emission Control System
Evaporative Emission (EVAPI Gontrols (cont'd)EVAP BYPASSSOLENOID VALVEY
(From page l1'291)
Check for a short in the wire{2WBS linel:Disconnect the 2P connector {romthe EVAP bypass solenoid valve.
Does the valve hold vacuum?
Repair short in the wire betweenEVAP bypass solenoid velve andrhe ECM/PCM {A3).
Ooes the valve hold vacuum?
Check the EVAP bvpr$ 3olenoid
1. Turn the ignition switch OFF.2. Connect ECM/PCM connectorterminal A3 and body groundwith a jumper wire.3. Turn the ignition switch ON (ll).Ch€ck lor an op.n in the wirellcl linol:1. Turn the ignition switch OFF.2. Disconnect the 2P connectorfrom the EVAP bypass sole-noid valve.3. Turn the ignition switch ON (lll.
4, Measure voltage between theEVAP bypass solenoid valve2P connector terminal No. 1and body ground.
Does the valve hold vacuum?
Repair open in the wir6 b€tw€€nEVAP purg6 control 3olanoid valveand the No. 15 ALTERNATOR SPSENSOR {7.5 A) Iuse.
Wire side ol female terminals
EVAP SYPASS SOLENOIOVALVE 2P CONNECTOR IC793}
tG1{BLK/WHT)
Wire side offemaleterminals
{To page 11 293)
11-292
(To page 11 293i

I
\
\l
(From page 11-292i
Chock the tollowing parts tolleakage to aimosphero, and
ropaii or replaco if necess6.y:. fuel fill cap. fuel tank. fuel v.por pipe. EVAP two way valve. EVAP bypas solonoid valve. tuel tank pre3suae sen3or. EVAP control cankter. EVAP control canisier veni3hut valve. EVAP purge conttol solenoid
. ORVR vent 3hut valve. ORVB vaoor recirculation valve. vacuum hoses tnd connactions
(From page 11 292)
Check toi an opon in the wiro(2wBS linol:1. Turn the ignition switch OFF.2. Reconnect the 2P connectorto the EVAP bypass solenoid
3. Turn the ignition switch ON (ll).
4. Measure voltage betweenECM/PCM connector terminals43 and 82.
Reprir opan in tho wire be(wean
th. EVAP byp.is solonoid valve
rnd rhe EcM/PcM (A31.ls there baftery voltage?
(cont'd)
11-293

Automatic Transmission
Special Tools ......... .....'."".'-.-.' 14'2
Description .,....................-...... 14-3
power Flow ......,................. 14"6
Elestronic Control System .... . ................'..'.'.. 14-13
Hvdraulic Control .....'......" 1'l-19
Hydraulic F|ow...... .'.'.".'....11-21
Lock-up System '............ ... t/t'33
Electrical System
Component Locations....,.............'......'.............'.,. 14'39
PCM Circuit Diagram
lA/T Control Syst€m: '96 - 98 Models) .........'.. 1/t-40
PCM Tarminal Volt8ge/Measuring Condhions
{'96 - 98 ModeblA/T Control System ............
PCM Circuit Disgram(A/T Conlrol System: '99 - 00 Modsls) '..........' 14-44
PCM Terminal Voltage/Measuring Conditions('99 - 00 Models)A/T Control System ...
Troubleshooting Proceduros ....
Symptom-to-ComPonent Chari
Efectricaf SFiem - '96 - 98 Models '..-.-..."'.'..11-52
Eloqtrical System -'99 - 00 Modols ... .........". 1+54
EleclricatTroubl$hooting ('96 - 98 Models)
Valve Body
Repair .................... ........'.... 14-139
Valve
Assembly
ATF Pump
1,1-1i10
Inspection ...........'.......... 14-141
Main Valvs Body
Disass€mbf y/lnspoction/R.sssembly .'.'.'.'.. -. -. 1 1-1 12
Secondsry Valve BodY
Disa$embfy/lnspoction/Rsassembly ......'.'.'.'. 11-111
Regulator Valve Body
Disa$embly/lnspoction/Rea3sembly ..........'... 14-1{5
Servo Body
Disassombly/lnsp€ction/Reassembly .".'........ 14-146
Lock-up Valv6 Body
Dis$s.mbf y/ln3poction/Rea$embly .'.. -. -..'.'.' 1 1-1 17
Mainsh!ft
Dkassembly/lnep€ction Reassembly ..'...'........ 14'148
Inspoction .............'..........'. l it-149
Countsrshaft
Disa$embly/lnspeqtion/Rea3sembly .......'...'.. 1a-l51
Dba$ombly/Re$s.mblY11-152
til-46
I rl-48
Troubleshooting Flowcharts
Electrical Troubleshooting ('9!t - 00 Models)
Troublsshooting Flowchart3
Lock-up Control Solenoid vslvo A/B AssemblY
RePlacoment
Shift Cont.ol Solenoid Valve A/B A3sembly
Inspestion
Ona-way Clutch
Disassembh/lrupoction/Rca$embly .. "'........ l4-155
Clutch
lllustlttcd Ind.x {A48A, B4RA Transmlssion) ..' 14-156
tustr.tod Index (MrnA Transmi$ionl ............ til-158
...................... 14-153
L
14-56
1+81'
14-105
1+105
Replacoment ......
Mainshaft/Countorshaft Spo€d Sonsors
Replacemsnt ......'."'........... lit'108
Hydraulic System
Symptom-to-Componeni Chart
Hydraulic Sydemr+109
t4-113
1+116
11-117
Rea$emblY
14-106 Difforrr ial
llhdraied Index........ t4-156
B.ckhrh ln3poction. 14-167
Boaring Roplacemont..-..........11-167
..... 14-108 Diftrrsniial Carrior Repl8cemeni .'.-.............'...' lil-168
Oil Sall Romovalt4-t 59
Oil Soal ln3tallstion/Sidc Clearance'......'.....'... 1'l'169
Torqua Convertcr Housing Boarings
Mlin3haft Besring/Oil Scal Roplac.ment ."..'.. lil-172
Counio6hatt Betring R.plscem.nt ..'...... ....... 14-173
Test.....,......14-106
14-107
14-160
11-162
11-171
11-175
Replacement
Test .....,.,..........
Road Te3t
Linear Solenoid AsssmblY
Stall Speed
lllustrated Indax
Transmission/End Cover'. ....
Transmission Hou3ing,.............'.'......'....""..-.-.. 11-128
Torque Conve.ter Housing/Valvo Body ........... 14-130
End Cover
14-itB Park Stop
1+119 In3pection/Adiustmsnt...'......'.'............'...."""'14-175
Transmbgion
Reassombly
11-122 Torquo Convertet/Drivr Plsie ............'.'............'.. . l4-182
Transmission
11.726 Inrtallation
Tranlmission Housing Boarings
Msinsh.ft /CounteEhaft Bearings
B!pltcomgnt
Rcvo.3s ldlor Gear
lnrtallation
Cooler Flushing ..
Shift Cabls
Test
Fluid Level
Checkin9 .........."..'.'.....
Changing
Pressure Testing
Transmission
Transmission
Rgmoval ..
lil-176
.'..........'.'.'..... 1'l-183
.... lil-187
11-132Adiustmont
RemovaUlnttallation1,1-190
lit-191Transmisgion Housing
Removal ... '.'...... ......'..... 14-l3il
Tolque Convgrter Housing/valvs Body
Rsmoval .........,...... ............. 14-136
Valve CaDs
Description .......'................. t 4'138
Shift lndicator Panel
Adiu3tmant ..'.................. 14-192
ATF Coolor Hoses
Connection ..,............,.,....... l'l-192
Shift Lever .,........

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

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

Description
Electronic Control System (cont'd)
Shift Control
The PCM instantaneously determines which gear should be selected by various signals sent from sensors, and actuatesthe shift control solenoid valves A and B to control shifting. Also. a Grade Logic Control System has been adopted to con-trol shifting in E position while the vehicle is ascending or descending a slope, or reducing speed.
PoshionGearShift Control Solenoid
Vslve A
Shift Control Solenoid
Valve B
8,tr
1stOFFON
2ndONON
3rdONOFF
E4thOFFOFF
tr2ndONON
E-ReverseONOFF
*See page 14-31 for reverse inhibitor control description.
Lock-up Control
From sensor input signals, the PCM determines whether to turn the lock-up ON or OFF, and activates lock-up controlsolenoid valve A and/or B accordingly. The combination of driving signals to lock-up control solenoid valves A and B andthe linear solenoid pressure is shown in the table below.
Lock-up ConditionsLock-up Control
Solenoid Valvo A
Lock-up Control
Solenoid Valve B
Linoar Solonoid
Prggguro
Lock-up OFFOFFOFFHigh
Lock-up, HalfONDuty operation
OFF * ONLow
Lock-up, FullONONHigh
LOCK-Up
during decelerationONDuty operation
OFF - ON
a
14-14

GRADE LOGIC CONTROL SYSTEM
How it works:
The pCM compares actual driving conditions with driving conditions memorized in the PCM, based on the input from the
vehicle speed sensor, the throttle position sensor, the barometoric pressure sensor, the engine coolant temperature sensor,
the brake switch signal, and the shift lever position signal, to control shifting while a vehicle is ascending or descending a
slope, or reducing speed.
SIGNALS OETECTED
O.iving Resi3lence
Judgemenl ot Conirolling Arca
. Ascending mod€
lFuzzy loqicl. Gradual Ascending mode' Ste€p Ascending mode. Oescending mode. Gr.du.l Descending mode. Steep D6cending mode
14-15

Description
Electronic Control System {cont'dl
Ascending Control
When the PCM determines that the vehicle is climbing a hill in E position, the system oxtends the sngagement area of2nd gear and 3rd gear to prevent ths transmission from fr€quently shifting between 2nd and 3rd gears, and between 3rdand 4th gears, so the vehicle can run smooth and have more power when needed. There are two ascending modes withdifferent 3rd gear driving areas according to the magnitude of a gradient stored in the pCM.
NOTE:
. The PCM memory contains shift schedules between 2nd and 3rd gears, and between 3rd and 4th gears that enable thePCM's fuzzy logic to automatically select the most suitable gear according to the magnitude of a gradient. Fuzzy logic is a form of artificial intelligence that lets computers respond to changing conditions much like a humanmind would,
Dssconding Control
When the PCM determines that the vehicle is going down a hilt in E position, the shift-up speed from 3rd to 4th gearwhen th€ throftle is closed becomes faster than the set speed for flat road driving to widen the 3rd gear driving area.This, in combination with engine braking from the deceleration lock-up, achieves smooth driving when the vehicle isdescending. There are two descending modes with different downshift (4 - 3) schedules according to the magnitude of agradient stored in the PCM. When the vehicle is in 4th gear, and you are decelerating on a gradual hill, or when you areapplying the brakes on a steep hill, the transmission will downshift to 3rd gear. When you accel6rate, the transmission willthen return to 4th gear.
ASCENDING MODEDESCENDING MODE
4TH SHIFTING
L.
F
CHARACTERISIICSCONTROL AREA
ff.1"11", vehicr. 3pe€dff;Tlr., vohicre speed
GRADUAL ASCENOINGCONTROL AREA
Docel6ration Control
When the vehicle goes around a corner. and needs to first decelerate and then accelerate. the rcM sets the data for decelerationcontrol to reduce the number of times the transmission shifts. When the vehicle is decelerating from speeds above 26 mph(41 km/h), the rcM shifts the transmission from 4th to 2nd earlier than normal to cope with upcoming acceleration.
14-16