1996 HONDA CIVIC Engine control

Description
Hydraulic Control (cont'dl
Regulator Valve
The regulator valve maintains a constant hydraulic pressure from the ATF pump to the hydraulic control system, whitealso furnishing fluid to the lubricating system and torque converter. The fluid from the ATF pump flows through B and 8,.The regulator valve has a valve orifice. The fluid entering from B flows through the orifice to the A cavity. This pressure ofthe A cavity pushes the regulator valve to the right side, and this movement of the regulator valve uncovers the fluid portto the torque converter and the relief valve. The fluid flows out to the torque converter, and the relief valve and regulatorvalve moves to the left side. According to the level of the hydraulic pressure through B, the position of the regutator vatvechanges and the amount of the fluid from B' through D and c also changes. This operation is continued. maantaining theline pressure,
NOTE: When used. "|eft" or "right" indicates direction on the illustration betow.
ENGINE NOT RUNNING
TOROUE CONVERTER
ENGINE RUNNING
To TOROUE CONVERTER Lubrication
Stator Roaction Hydraulic Prossur6 Control
Hydraulic pressure increases according to torque, are performed by the regulator valve using the stator torque reaction.The stator shaft is splined with the stator in the torque converter, and its arm end contacts the regulator sprang cap. whenthe vehicle is accelerating or climbing (Torque Convert€r Range), the stator torque reaction acts on the stator shaft, andthe stator arm pushes the regulator spring cap in the direction of the arrow in proponion to the reaction. Jne stator reac-tion spring compresses, and th€ reoulator valve moves to increase the line pressure which is regulated by the regulatorvalve. The line pressure reaches its maximum when the stator torque reaction reaches its maximum.
STATOR SHAFT ARM
REGULATOR VALVE
14-22
STATORATOR SHAFT ARM
SPRING CAP

E! or l8! Position
1. lst Gear
The flow of fluid through the torque converter circuit is same as in E position, The line pressure tlows to the manual
valve and the modulator valve. The line pressure changes to the modulator pr€ssure (6) at the modulator valve and to
the line pressure (4) at the manual valve. The modulator pressure (61 flows to the lsft end of the 1-2 shift valve and the
3-4 shift valve because shift control solenoid valve A is turned OFF and B is turned ON by the PCM. The 1-2 shift valve
is moved to the right side. The line pressure (4) changes to the lst clutch pressure (10) at the 1-2 shift valve and the
oritice. The lst clutch pressure (10) is applied to the 1st clutch and tho 1st accumulator; consquently, the vehicle will
move as the engine power is transmitted.
NOTE: When used, "|eft" or "right" indicates direction on the hydraulic circuit'
(cont'd)
14-27

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
PCM CONNECTOR B {25P1 {cont'dl
Terminal NumberSignalDescriptionMeasuring Conditions/Terminal Vohage
811SHBShift control solenoid valve B
control
In 1st gear and 2nd gear in -q1, q11 position,
and in E] position: Battery voltage
In 3rd gear and 4th gear in lD.J, [Dr- position: 0 V
B't2SLUInterlock controlWhen ignition switch is ON (ll), brake pedal
deoressed and accelerator Dedal released: 0 V
813D4 INDD4 Indicator light controlWhen ignition switch is first turned ON (ll):
Battery voltage for two seconds
In E position: Baftery voltage
B't 4NMSGMainshaft speed sensor groundAlways: 0 V
E tcNMMainshaft speed sensor signal
input
Depending on engine speed: Pulsing signal
When engine is stopped: 0 V
816ATP RAy'T gear position switch Eposition signal input
InE position: 0V
In other than E position: Battery voltage
817ATP 2A/T gear position switch E posi-
tion signal input
InE position: 0V
In orher than E position: Battery voltage
818 to 821Not used
s22NCSGCountershatt speed sensor groundAlwaysr 0 V
B23NCCountershaft speed sensor signal
input
Depending on vehicle speed: Pulsing signal
When vehicle is stopped: 0 V
B24ATP D4Ay'T gear position switch lor posi-
tion signal input
InEposition:0V
In other than 6 position: 5 V
ATP NPA,/T gear position switch E and
N position signals input
InE and E positions: 0V
In otherthan E and N] positions: Battery voltage
PCM CONNECTOR C {31P)
Terminal NumberSignalDescriptionMeasuring Conditions/Terminal Voltage
Cl to C6- see section 11 -
c1Service check signalWith ignition switch ON (ll) and service check
connector oDen; 5 V
With ignition switch ON (ll) and service check
connector connected with sDecial tool: 0 V
C8 to Cg- see section 11 -
c10VBUBack-up power systemAlways battery voltage
C11 to C31- see section '11 -
PCM CONNECTOR D (16P}
Terminal NumberSignalDescriptionMeasuring Conditions/Terminal Voltage
Dl to D4- see section 11 -
D5STOP SWBrake switch signal inputBrake pedal depressed: Battery voltage
Brake pedal released: 0 V
D6 to D16- see section 1 l -
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FCM CONNECTOR D {16P)
\o
14-47
Terminal NumberSignalDo3criptionMeasuring Conditions/Torminal Vohage
D1LCALock-up control solenoid valve A
control
When lock-up is ON: Battery voltage
With no lock-up: 0 V
SHBShift control solenoid valve B
control
In E position, in 1st and 2nd gear in E, E
position: Battery voltage
ln 3rd gear in E, E, in 4th gear in E posi-
tion;0 V
D3LCBLock-up control solenoid valve B
control
When full lock-up: Battery voltage
With half lock-up: Pulsing signal
D4Not used
D5VB SOLLock-up control solenoids, shift
control solenoids and linear
solenoid power supply electrode
with ignition switch oN (ll): Battery voltage
With ignition switch OFF: 0 V
D6ATP RAy'T gear position switch
E position input
tnEposition:0V
In other than E position: Approx. 10 V
SHAShift control solenoid valve A
control
In E] position, in 2nd and 3rd gear in p!, [Q]
position: Battery voltage
In 1st gear in E, @ position, in 4th gear in El
Dosition: 0 V
D8ATP D3A/T gear position switch
E position input
In E position:0V
In otherthan @ position: Approx. 10 V
D9ATP D4Ay'T gear position switch
E position switch
In El position: 0 V
In other than E position: Approx. 5 V
D10NCCountershaft speed sensor signal
input
Depending on vehicle speed: Pulsing signal
When vehicle is stooped: 0 V
D11NMMainshaft speed sensor signal
Inpur
Depending on engine speed: Pulsing signal
When engine is stopped: 0 V
D't2NMSGMainshaft speed sensor ground
D13ATP NPAy'T gear position switch E and
E position input
InE and E positions: 0V
In other than E and E positions: Approx. 10 V
D14AfP 2Ay'T gear position switch
E position input
tnEposition;0V
In other than E position: Approx. 10 V
D16NCSGCountershaft speed sensor
ground

Electrical Troubleshooting ('96 - 98 Models)
Troubleshooting Flowchart - Lock-up Control System
NOTE: Record all freeze data before vou troubleshoot.
Possible Cause
Faulty Lock-up cont.ol system
NOTE: Do not continue with this troublesnoonnoother DTCS have been corrected.until the causes of any
. OBD ll Sc6n Tool indicatG Codem7{0.. Self-diagnosis E indicator lightindicates Code 40.
Check tor Another Code:Check whether the OBD ll scantool or the E indicato, lightindicates another code.
Perform lhe Troublo3hooiingFlowchart tor the indicatedCode(s). Recheck for cod. P07il0lilol aftor iroubl€3hooting.
Does the OBD ll scan tool orthe E indicator light indicateanother code?
Tast Line Pressure:Measure the line pressure (seepage 14-119 and 14-120).
Repair tho hydreulic aystem a3necessary {3ee page 14-119).
Replace the Lock-up ControlSolenoid Valve Assembly andR6check;1. Beplace the lock up controlsolenoid valve Ay'B assembly(see page 14-105).2. Turn the ignitaon switch OFFand reset the PCM by removing the BACK UP (7.5 A) fusein the underhood fuse/relaybox for more than 10 seconds,3. Using the scan tool, check tobe sure that the engine coolant temperature is in 176'F(80'C) and above.4. Drive the vehicle at 55 mph(88 km/h) constantly for morethan one minute.5. Recheck for code P0740 (40).
Does the OBD ll scan toolindicate code P0740 {40)?The systom k OK at this time.
l'.
14-74

Troubleshooting Flowchart - Lock-up Control System
NOTE: Record all freeze data before vou troubleshoot.
Possibl€ Cause
Faulty Lock-up control sy3tem
NOTE: Do not continue with this troubleshootingother DTCS have been corrected.until the causes of any
OBD ll Scan Tool indicates Codem14/J.S€lf-diagnosis .D4l indicalor lightindicates Code 40.
Check for Another Code:Check whether the OBD ll scantool or the :E indicator lightindicates another code,
Perform the TroubleshootingFlowchart tor the indicatedCodels|. Rocheck to. code P0740(40) .fter troublBhooting.
ooes the OBD ll scan tool orrhe E indicator light indicateanother code?
Test Line Pressure:Measure the line pressure (see
page 14 119 and 14-120).
Repair the hydrrulic sy3tem asn6c6ssary (see page 14-1191.ls the lane pressure within theservice limit?
Replace the Lock-up ControlSolenoid Valve Assembly andRecheck:1. Replace the lock-up controlsolenoid valve A/B assembly(see page 14-105).2. Turn the ignition switch OFFand reset the PCM by removing the EACK UP (7.5 A) fusein the underhood {use/relaybox for more than 10 seconds.3. Using the scan tool, check tobe sure that the engine cool-ant temperature is in 176'F(80'C) and above.4. Drive the vehicle at 55 mph(88 km/h) constantly for morethan one minute,5. Recheck for code P0740 {40).
Does the OBD ll scan toolindicate code P0740 (40)?The svstem i3 OK .t this time.
14-99

Symptom-to-Component Chart
Hydraulic System (cont'dl
G.
n,
set idle rpm in gear to specified idle speed. lf still no good, adjust motor mounts as outlined in enginesection of this manual.
lf the clutch pack is seized or is excessively worn. inspect the other clutches for wear, and check the orificecontrol valves, CPC valve and linear solenoid for free movement.
lf the linear solenoid is stuck, inspect the clutches for wear.
lmproper alignment or main valve body and torque converter housing may cause ATF pump seizure. Thesymptoms are mostly an rpm-related ticking noise or a high-pitched squeak.
lf the l st clutch feed pipe guide in the end cover is scored by the mainshaft, inspect the ball bearing forexcessive movement in the transmission housing. lf oK, replace the end cover as it is dented. The o-rinounder the guide is probably worn.
Replace the mainshaft if the bushing for the 4th feed pipe is loose or damaged. lf the 4th feed pipe is danFaged or out of round, replace the right side cover.
Replace the mainshaft if the bushing for the 1st feed pipe is loose or damaged. lf the 1st feed pipe is darn-aged or out of round, replace it.
A worn or damaged sprag clutch is mostly a result of shifting the transmission inthe wheels rotate in reverse, such as rocking the vehicle in snow.
or E position while
Inspect for damage and wear:
1. Reverse selector gear teeth chamfers.
2. Engagement teeth chamfers of countershaft 4th and reverse gear.
3. Shift fork for scuff marks in center.
4. Differential pinion shaft for wear u nder pin ion gears.
5. Bottom of 3rd clutch for swirl marks.
Replace items 1,2,3 and 4 if worn or damaged. lf transmission makes a clicking, grinding orwhirring noise,also replace mainshaft 4th gear, reverse idler gear. and countershaft 4th gear in addition to 1, 2, 3 or 4.lf differential pinion shaft is worn, overhaul differential assembly, and replace ATF strainer, and thoroughlyclean transmission, flush torque converter, cooler and lines.lf bottom of 3rd clutch is swirled and transmission makes gear noise, replace the countershaft and final drivengear.
Be very careful not to damage the torque converter housing when replacing the main ball bearing, you
may also damage the ATF pump when you torque down the main valve body. This will result in ATF pumpseizure if not detected. Use the oroper roors.
Install the main seal flush with the torque converter housing. lf you push it into the torque converterhousing until it bottoms out, it will block the fluid return passage and result in damage.
See flushing procedure, page 14-187 and 188.
lf the large clutch piston O-ring is broken, inspect the piston groove for rough machining.
lf the l-2 shift valve is stuck closed, the transmission will not upshift. lf stuck open, the transmission hasno 1st gear.
lf the znd orifice control valve is stuck. inspect the 2nd and 3rd clutch oacks for wear.
lf the 3-4 orifice control valve is stuck, inspect the 3rd and 4th clutch oacks for wear.
lf the clutch pressure control valve is stuck closed, the transmission will not shift out of 1st gear.
lf the ATF strainer is clogged with particles of steel or aluminum, inspect the ATF pump and differentialpinion shaft. lf both are OK and no cause for the contamination is found, replace the torque converter.
Inspect the frame for collision damage.
14-112