throttle HONDA CIVIC 1999 6.G Repair Manual

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

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

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

Road Test
NOTE: Warm up the engine to normal operating tem peratu re (the rad iator fan comes on )'
1. Apply parking brake and block the wheels. Start the engine, then shift to E position while depressing the brake
Dedal, Depress the accelerator pedal and release it suddenly. The engine should not stall'
2. Repeat same test in E Position.
3. Test-drive the vehicle on a flat road in the E position. Check that the shift points occur at approximate speeds shown
in the table. Also check for abnormal noise and clutch slippage.
NOTE: Throttle position sensor voltage represents the throttle opening
a. Unbolt the PCM for road testing; refer to page 14-50.
b. Setthedigital multimeter to check the th rottle position sensor voltage between PCM terminals;
. '96 - 98 models: D1 {+) and A9 (-) or 422 (-}.
. '99 - 00 models: C27 (+) andB20t-) orB22{-}.
BACKPROBE ADAPTER
BACKPROBE SET07sAz - 001oq)A{two requiredl
DIGIIAL MULTIMETERlCommercially available)KS-AHM-32-003,or equivalenl
'96 - 98 Modelsr
Wire side ol temale terminals
PCM CONNECTORS
B t25Pl c (31P)
LG1 IBRN/BLK)
I (25P1c (31P}
A t32PtD (16P)
Wire side ol female terminals
'9!t - 00 Models:
1+113

Road Test
(cont'dl
.91 Position: Dl6Y7 engine
. Upshift
Throttle OpeningUnit of speedlst + znd2nd * 3rd3rd t 4thLock-up ON
Throttle position sensor
voltage: 0.75 V
mph9-1220-2328-3221 -24
km/h15-1932-3745-5234-39
Throttle position sensor
voltage:2.25 V
mph40-4562-67
km/h34-4095 - 10499 - 't08
Fully-opened throttle
Throttle position sensor
voltage: 4.5 V
mph33-38101 - 't1299 - 109
km/h53-61102-115163 - 180'159 - 176
Downshift
Throftle OpeningUnit of speedLock-up OFF'lth + 3rd3rd + 2nd2nd t lst
Fully closed throttle
Throttle position sensor
voltage: 0.5 V
mph't9 - 2217 -206-9(3rd+lst)
km/h30-3527 -3210 - 15 (3rd + 1st)
Fully-opened throttle
Throttle position sensor
voltage: 4.5 V
mpn95 - 10585-9554-6125-30
km/h153 - 169137 - 15387-9840-48
-q1 Position: DI6YB engine
. Upshift
Downshift
NOTE:
. Lock-up ON: The lock-up control solenoid valve A turns ON.. Lock-up OFF: The lock-up control solenoid valve A turns OFF.
Throttle OpeningUnit of speedlst + 2nd2nd - 3rd3rd + 4thLock-up ON
Throftle position sensor
voltage: 0.75 V
mph9-1220-232A-3221 -24
km/h15-1932-3745-5234-39
Throttle position sensor
voltage:2.25 V
mpn21 -2540-4559-65
km/h34-4095 - 10499 - 108
Fully-opened throttle
Throttle position sensor
voltage: 4.5 V
mph32-3762 -7096 - 10795 - 106
km/h52-60100 - 113't55 - 112't53 - '170
Throttle OpeningUnit ot speedLock-up OFF'lth + 3rd3rd+2nd I 2nd+lst
Fully-closed throttle
Throttle position sensor
voltage: 0.5 V
mph19-2217 -206-9(3rd+ 1st)
km/h30-3527 -32l0 - 15 (3rd + lst)
Fully opened throttle
Throttle position sensor
voltage: 4.5 V
mpn91 - 10154-61 25-30
km/h'147 - 163137 - 15387-98 I 40-48
l.
14-114

Accelerate to about 35 mph (57 km/h) so the transmlssion is in 4th, then shift from Dl position to Z position The
vehicle should immediately begin slowing down from engine braking'
CAUTION: Do not shift from -91 or -Dd position to E position at speeds ov6r 63 mph {100 km/hl; You mav damage
the transmission.
Check for abnormal noise and clutch slippage in the following positions'
E (2nd Gear) Position
ll Accelerate from a stop at full throttle. check that there is no abnormal noise or clutch slippage.
b. Upshifts and downshifts should not occur with the selector in this posirion'
E (Reverse) Position
i"ccelerate from a stop at fullthrottle, and check for abnormal noise and clutch slippage'
Test in B (Park) Position
Park the vehicle on slope (approx. l6'), apply the parking brake' and shift into E position Belease the brake; the veh'
cle shou,d nol move
1+115

E, E, and E Positions {Forward Rangel
. Sta rt Clutch: engaged
. Forward Clutch: engaged
o Reverse Brake: released
1, The hydraulic pressure is applied to the forward clutch and the start clutch, and the sun gear drives the torward
clutch.
2. The torward clutch drives the drive pulleV shaft. which drives the driven pulley shaft linked by the steel belt.
3, The driven pulley shaft drives the secondary drive gear, via the start clutch.
4. Power is transmitted to the secondary driven gear, which drives the final driven gear.
NOTE: The working hydraulic pressure on the movable face of each shaft depends on the throttle opening position.
DRIVE PULI.f YFLYWHEELSTEEL AELT
CLUTCH
INPUT SHAFT
START CLUTCH
SECONDARY DRIVENGEAR
(cont'd)
FINAL DRIVEN GEAR
14-201

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
z
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
Electronic Control System ('99 - 00 Modelsl (cont'dl
Grade Logic Control System
How it works:
The PcM compares actual driving conditions with memorized driving conditions. based on the input from the vehiclespeed sensor, the throttle position sensor, the manifold absolute pressure sensor, the engine coolant temperature sensor,the brake switch signal, and the shift lever position signal, to control shifting while the vehicle is ascending or descendinga slope.
Ascending Control
When the PCM determines that the vehicle is climbing a hill in E position, the system selects the most suitable shiftschedule (pulley ratio) according to the magnitude of a gradient. so the vehicle can run smooth and have more powerwhen needed. There are three ascending modes with different shift schedules according to the magnitude ot a gradient inthe PCM.
Descending Control
when the PCM determines that the vehicle is going down a hill in E position. the system selects the most suitable shiftschedule (pulley ratio) according to the magnitude of a gradient. This, in combinstion with engine braking, achievessmooth driving when the vehicle is descending, There are three descending modes with different shift schedules accord-ing to the magnitude of a gradient in the PCM.
L
14-206