ACURA RL KA9 1996 Service Repair Manual

Description
Power Flo w (cont'd )
Position
Position is provide d to driv e onl y in 2n d gear .
In position , hydrauli c pressur e i s applie d t o th e 2n d clutc h an d t o th e 1st-hol d clutch .
Th e powe r flo w whe n acceleratin g i s a s follows :
1 . Th e hydrauli c pressur e is applie d t o th e 2n d clutc h o n th e mainshaft , an d powe r i s transmitte d vi a th e 2n d clutc h t o th e
mainshaf t 2n d gear .
2 . Powe r transmitte d t o th e mainshaf t 2n d gea r i s conveye d vi a th e countershaf t 2n d gea r t o th e 2n d gea r one-wa y clutc h
o n th e insid e o f th e countershaf t 2n d gear . Th e 2n d gea r one-wa y clutc h i s use d t o driv e th e par k gea r o n th e counter -
shaft .
3 . Powe r i s transmitte d t o th e secondar y driv e gear , whic h drive s th e secondar y drive n gear . Hydrauli c pressur e i s applie d
t o th e 1st-hol d clutch , bu t th e countershaf t i s rotate d b y th e 2n d gea r one-wa y clutch .
TORQU E CONVERTE R
MAINSHAFT
2N D GEA R
2ND CLUTC H
MAINSHAF T
SECONDAR YDRIVE GEA R COUNTERSHAF
T
2ND GEA RONE-WA Y CLUTC H
COUNTERSHAF T
2ND GEA R
SECONDAR Y DRIVE N GEA R PAR
K GEA R
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Position

The power flow when decelerating is as follows:

1. Rolling resistance from the road surface goes through the front wheels to the secondary drive gear, then to the counter-

shaft 1st gear via the Ist-hold clutch which is applied during deceleration.

2. Power transmitted to the countershaft 1st gear is conveyed via the 1st gear one-way clutch on the inside of the counter-

shaft 1st gear to the countershaft 2nd gear. The 1st gear one-way clutch is used to drive the countershaft 2nd gear.

3. The 2nd gear one-way clutch disengages at this time because the application of torque is reversed.

4. The counterforce conveyed to the countershaft 1st gear turns the mainshaft 2nd gear. At this time, since hydraulic pres-

sure is applied to the 2nd clutch, counterforce is transmitted to the mainshaft. As a result, engine braking can be

obtained with 2nd gear.

TORQUE CONVERTER

MAINSHAFT

2ND GEAR
2ND CLUTCH

MAINSHAFT

SECONDARY

DRIVE GEAR
COUNTERSHAFT

1ST GEAR

ONE-WAY CLUTCH

COUNTERSHAFT

1ST GEAR

SECONDARY DRIVEN GEAR
1ST-HOLD

CLUTCH
COUNTERSHAFT

2ND GEARProCarManuals.com

Description
Power Flo w (cont'd )
In o r position , th e optimu m gea r i s automaticall y selecte d fro m 1st , 2nd , 3rd , an d 4t h gears , accordin g t o condition s
suc h a s th e balanc e betwee n throttl e openin g (engin e load ) an d vehicl e speed .
or Position , 1s t gea r
1 . Th e hydrauli c pressur e i s applie d t o th e 1s t clutch , whic h rotate s togethe r wit h th e mainshaft , causin g th e mainshaf t 1s t
gea r t o rotate .
2 . Powe r i s transmitte d t o th e countershaf t 1s t gear , whic h drive s th e countershaf t vi a th e one-wa y clutches .
3 . Powe r i s transmitte d t o th e secondar y driv e gear , whic h drive s th e secondar y drive n gear .
NOTE : I n o r position , hydrauli c pressur e i s no t applie d t o th e 1st-hol d clutch .
TORQU E CONVERTE R
MAINSHAFT
1ST GEA R
2ND GEA R
ONE-WA Y CLUTC H
1ST GEA RONE-WA Y
CLUTC H MAINSHAF
T
COUNTERSHAF T
SECONDAR Y DRIVE N
GEAR
COUNTERSHAF T1ST GEA R
PARK GEAR
SECONDARYDRIVE GEAR
1ST CLUTCH
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or Position, 2nd gear

1. The hydraulic pressure is applied to the 2nd clutch, which rotates together with the mainshaft, causing the mainshaft

2nd gear to rotate.

2. Power is transmitted to the countershaft 2nd gear, which drives the countershaft via the 2nd gear one-way clutch.

3. Power is transmitted to the secondary drive gear, which drives the secondary driven gear.

NOTE: In or position, 2nd gear, hydraulic pressure is also applied to the 1st clutch, but since the rotation speed

of 2nd gear exceeds that of 1st gear, power from 1st gear is cut off at the 1st gear one-way clutch.

TORQUE CONVERTER

SECONDARY

DRIVE GEAR
MAINSHAFT

2ND GEAR

2ND CLUTCH

MAINSHAFT

COUNTERSHAFT

2ND GEAR

ONE-WAY CLUTCH

COUNTERSHAFT

2ND GEAR

SECONDARY DRIVEN GEAR
1ST GEAR

ONE-WAY

CLUTCH
PARK GEARProCarManuals.com

Power Flo w (cont'd )
or Position , 3r d gea r
1 . Th e hydrauli c pressur e i s applie d t o th e 3r d clutch . Powe r fro m mainshaf t 3r d gea r i s transmitte d t o th e countershaf t
3r d gear .
2 . Powe r i s transmitte d t o th e secondar y driv e gear , whic h drive s th e secondar y drive n gear .
NOTE : I n o r position , 3r d gear , hydrauli c pressur e i s als o applie d t o th e 1s t clutc h an d t o th e 2n d clutch , bu t
sinc e th e rotatio n spee d o f 3r d gea r exceed s tha t o f 2n d gear , powe r fro m 2n d gea r i s cu t of f a t th e 2n d gea r one-wa y
clutch .
TORQU E CONVERTE R
SECONDAR YDRIVE GEA RCOUNTERSHAF T
2ND GEA RONE-WA Y CLUTC H
COUNTERSHAF T
2ND GEA R
SECONDAR Y DRIVE N GEA R
3RD CLUTCH
COUNTERSHAFT3RD GEA R MAINSHAFT
2ND CLUTCH
1ST
CLUTCH
MAINSHAFT 3RD GEAR
Description
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Position, 4th gear

1. The 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 secondary drive gear, which drives the secondary driven gear.

NOTE: In position, 4th gear, hydraulic pressure is also applied to the 1st clutch and to the 2nd clutch, but since the

rotation speed of 4th gear exceeds that of 2nd gear, power from 2nd gear is cut off at the 2nd gear one-way clutch.

TORQUE CONVERTER

MAINSHAFT

4TH GEAR
MAINSHAFT

2ND GEAR

SECONDARY

DRIVE GEAR

COUNTERSHAFT

2ND GEAR

SECONDARY DRIVEN GEAR
COUNTERSHAFT

4TH GEAR
2ND GEAR

ONE-WAY CLUTCH
COUNTERSHAFT
MAINSHAFT
2ND CLUTCH
4TH CLUTCH

1ST CLUTCHProCarManuals.com

Description
Power Flo w (cont'd )
Position
1 . Th e hydrauli c pressur e i s applie d t o th e revers e clutch . Powe r i s transmitte d fro m th e mainshaf t revers e gea r vi a th e
revers e idle r gea r t o th e countershaf t revers e gear .
2 . Th e rotatio n directio n o f th e countershaf t revers e gea r i s change d vi a th e revers e idle r gea r i n th e rea r cover .
3 . Powe r i s transmitte d t o th e secondar y driv e gear , whic h drive s th e secondar y drive n gear .
REVERS E IDLE R
GEA R MAINSHAF
T REVERS E
GEAR
COUNTERSHAF TREVERSE GEA R
TORQU E CONVERTE R
REVERSEIDLER GEA R
MAINSHAF T
COUNTERSHAF T
SECONDARYDRIVE GEAR
COUNTERSHAFTREVERSE GEAR
REVERS E CLUTC H
SECONDARY DRIVEN GEAR
MAINSHAF T
REVERSE GEAR
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Electronic Control System

The electronic control system consists of a Powertrain Control Module (PCM), sensors, a A/T clutch pressure control

solenoid and four solenoid valves. Shifting and lock-up are electronically controlled for comfortable driving under all con-

ditions. The PCM is located below the dashboard, under the front lower panel on the passenger's side.

PCM

Throttle Position Sensor

Signal

Engine Coolant Temperature

Sensor Signal

Indicator Light

Self-Diagnosis Signal
PGM-FI

Control System

Shift Control

Lock-up Control

A/T Control System

Self-Diagnosis

Function
Vehicle Speed Sensor

Signal

Service Check Connector

Shift Solenoid

Valve A

Shift Solenoid

Valve B

A/T Clutch Pressure Control

Solenoid Valve

Torque Converter Clutch

(Lock-up Control)

Solenoid Valve A

Torque Converter Clutch

(Lock-up Control)

Solenoid Valve B

Mainshaft Speed Sensor

Signal

Countershaft Speed

Sensor Signal
Interlock SystemProCarManuals.com

Description
Electronic Contro l Syste m (cont'd )
Shift Contro l
Th e PC M instantl y determine s whic h gea r shoul d b e selecte d b y variou s signal s sen t fro m sensors , an d i t actuate s th e
shif t solenoi d valve s A an d B to contro l shifting . Also , a Grad e Logi c Contro l Syste m control s shiftin g i n positio n whil e
th e vehicl e is ascendin g o r descendin g a slope , o r reducin g speed .
* : Se e pag e 14-3 6 fo r revers e inhibito r contro l description .
Lock-u p Contro l
Fro m senso r inpu t signals , th e PC M determine s whethe r t o tur n th e lock-u p O N o r OF F an d activate s torqu e converte r
clutc h (lock-u p control ) solenoi d valv e A and/o r B accordingly . Th e combinatio n o f drivin g signal s t o torqu e converte r
clutc h (lock-u p control ) solenoi d valve s A an d B is show n in th e tabl e below .
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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, throttle position sensor, engine coolant temperature sensor, barometric pressure sensor, brake

pedal position switch signal and shift lever position signal, to control shifting while a vehicle is ascending or descending a

slope.ProCarManuals.com