ACURA RL KA9 1996 Service Repair Manual

Description

Electronic Control System (cont'd)

Ascending Control

When the PCM determines that the vehicle is climbing a hill in position, the system extends the engagement area of

3rd gear to prevent the transmission from frequently shifting between 3rd and 4th gears, so the vehicle can run smooth

and have more power when needed.

NOTE:

• Shift schedules between 3rd and 4th gear stored in the PCM enable the PCM'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 human

mind would.

Descending Control

When the PCM determines that the vehicle is going down a hill in position, the shift-up speed from 3rd to 4th gear

when the throttle 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 is

descending. There are two descending modes with different downshift (4-3) schedules according to the magnitude of a

gradient stored in the PCM. When the vehicle is in 4th gear, and you are decelerating on a gradual hill, or when you are

applying the brakes on a steep hill, the transmission will downshift to 3rd gear. When you accelerate, the transmission will

then return to 4th gear.

ASCENDING MODE

DESCENDING MODE

3RD/4TH SHIFTING

CHARACTERISTICS

CONTROL AREA
Flat road

mode

Steep descending

mode

Gradual descending

modeProCarManuals.com

Circuit Diagram and Terminal LocationsProCarManuals.com

Description

The hydraulic control system is controlled by the ATF pump, valves and accumulators in the valve bodies. The ATF pump

is driven by splines on the end of the torque converter which is attached to the engine.

Fluid from the ATF pump flows through the regulator valve to maintain specified pressure through the main valve body to

the manual valve, directing pressure to each of the clutches.

The valve body includes the main valve body, the secondary valve body, the ATF pump body, the regulator valve body,

the throttle valve body, and the accumulator body. The throttle valve body is joined with the A/T clutch pressure control

solenoid valve.

The shift solenoid valves A and B are bolted on the secondary valve body. The torque converter clutch (lock-up control)

solenoid valves A and B are bolted on the outside of the torque converter housing.

ATF PUMP BODY

ACCUMULATOR BODY

SHIFT SOLENOID

VALVE B

SHIFT SOLENOID

VALVE A

REAR COVER

REGULATOR VALVE

BODY

THROTTLE VALVE BODY

SECONDARY VALVE BODY

ATF PASSAGE
MAIN VALVE BODY
Hydraulic ControlProCarManuals.com

Lower Valve Body Assembly

The lower valve body assembly is located on the bottom of the transmission housing. The lower valve body assembly

consists of the main valve body, the secondary valve body and the ATF passage.

Main Valve Body

The main valve body houses the manual valve, the 1-2 shift valve, the 2-3 shift valve, the 3-4 shift valve, the 4-3 kick-down

valve and the main orifice control valve. The primary functions of the main valve body are to switch fluid pressure on and

off and to control the hydraulic pressure going to the hydraulic control system.

Secondary Valve Body

The secondary valve body is located on the main valve body. The secondary valve body houses the line pressure control

valve, the modulator valve, the 3-4 orifice control valve, the 4-3 shift timing valve, the 1st accumulator piston and the 2nd

accumulator piston. The shift solenoid valves A and B are assembled on the secondary valve body.

Throttle Valve Body/A/T Clutch Pressure Control Solenoid Valve

The throttle valve body is joined with the A/T clutch pressure control solenoid valve which is controlled by the PCM. The

throttle valve body/A/T clutch pressure control solenoid valve is located on the secondary valve body. The throttle valve

body houses the throttle valve.

LINE PRESSURE

CONTROL VALVE

A/T CLUTCH PRESSURE CONTROL

SOLENOID VALVE

SHIFT SOLENOID

VALVE B

SHIFT SOLENOID

VALVE A

MODULATOR VALVE

1ST ACCUMULATOR

PISTON

SECONDARY VALVE

BODY

MAIN VALVE BODY

MANUAL VALVE

MAIN ORIFICE CONTROL VALVE
THROTTLE VALVE BODY

THROTTLE VALVE

2ND ACCUMULATOR

PISTON

3-4 ORIFICE CONTROL

VALVE

4-3

SHIFT TIMING VALVE

4-3 KICK-DOWN

VALVE

3-4 SHIFT VALVE

2-3 SHIFT VALVE

1-2 SHIFT VALVEProCarManuals.com

Hydraulic Control (cont'd)

ATF Pump Body

The ATF pump body is located on the torque converter housing. The ATF pump body consists of the ATF pump gears, the

relief valve, the lock-up control valve, the lock-up timing valve and the torque converter check valve. The torque converter

check valve is located between the ATF pump body and the torque converter housing.

Accumulator Body

The accumulator body is located on the torque converter housing next to the ATF pump body. The accumulator body

houses the 3rd accumulator piston and the 4th accumulator piston.

Regulator Valve Body

The regulator valve body is located on the ATF pump body. The regulator valve body consists of the regulator valve, the

cooler relief valve and the lock-up shift valve.

REGULATOR VALVE

BODY

REGULATOR VALVE

4TH ACCUMULATOR

3RD ACCUMULATOR
ATF PUMP BODY

RELIEF VALVE

LOCK-UP CONTROL

VALVE

LOCK-UP TIMING

VALVE

TORQUE CONVERTER

CHECK VALVE

COOLER RELIEF

VALVE

ACCUMULATOR BODY
LOCK-UP SHIFT

VALVE
DescriptionProCarManuals.com

Regulator Valv e
The regulato r valv e regulate s th e lin e pressure , an d als o supplie s th e flui d t o th e lubricatin g syste m an d torqu e converter .
T o regulat e th e lin e pressure , th e regulato r valv e passe s th e flui d fro m th e AT F pum p throug h th e lubricatin g syste m an d
th e torqu e converter , an d th e regulato r valv e receive s lin e pressur e contro l pressure .
Th e flui d fro m th e AT F pum p flow s throug h B an d B' . Th e flui d enterin g fro m B flow s throug h th e regulato r valv e orific e to
th e A cavity . Thi s pressur e o f th e A cavit y pushe s th e regulato r valv e t o th e righ t side . Th e lin e pressur e contro l pressur e
flow s t o th e righ t sid e o f th e regulato r valve , an d pushe s th e regulato r valv e to th e lef t side . A s a result , th e regulato r valv e
stay s a t a certai n position , an d maintain s it t o regulat e lin e pressure . Th e lin e pressur e contro l pressur e increase s accord -
in g t o th e throttl e openin g (throttl e B pressure) , whil e th e lin e pressur e increase s accordin g t o th e lin e pressur e contro l
pressure . Th e lin e pressur e ca n b e regulate d a wid e rang e b y th e lin e pressur e contro l pressure .
NOTE: Whe n used , "left " o r "right " indicate s directio n o n th e illustratio n below .
ENGIN E NO T RUNNIN G ENGIN E RUNNIN G
T o Torqu e Converte r LIN E PRESSUR E CONTRO L PRESSUR E
REGULATO R VALV E ORIFIC E
A CAVIT Y
REGULATO R VALV ETo Lubricatin g Syste m LIN
E PRESSUR E fro m AT F PUM P
Stato r Reactio n Hydrauli c Pressur e Contro l
Hydrauli c pressur e increase s accordin g to th e torqu e is performe d b y th e regulato r valv e usin g th e stato r torqu e reaction .
Th e stato r shaf t i s spline d wit h th e stato r i n th e torqu e converter , an d it s ar m en d contact s th e regulato r sprin g cap . Whe n
th e vehicl e is acceleratin g o r climbin g (Torqu e Converte r Range) , th e stato r torqu e reactio n act s o n th e stato r shaft , an d
th e stato r ar m pushe s th e regulato r sprin g ca p in th e directio n o f th e arro w in proportio n t o th e reaction . Th e stato r reac -
tio n sprin g compresses , an d th e regulato r valv e move s t o increas e th e lin e pressur e whic h i s regulate d b y th e regulato r
valve . Th e lin e pressur e reache s it s maximu m whe n th e stato r torqu e reactio n reache s it s maximum .
TORQUE CONVERTE RREGULATOR VALV E
REGULATO R VALV EBODY
STATO R(Inside torqu e converter )REGULATOR
SPRING CAPSTATOR SHAFT ARM
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Description
Hydraulic Flo w
Genera l Char t o f Hydrauli c Pressur e
Line Pressur e Modulato
r Pressur e
Throttl e B Pressur e
Clutc h Pressur e
Lin e Pressur e Contro l Pressur e
Torqu e Converte r Pressur e
Lubricatio n Pressur e
Distributio n o f Hydrauli c Pressur e
Regulato r Valv e
Manua l Valv e - Torqu
e Converte r Pressur e
• Lubricatio n Pressur e
T o Regulat e Lin e Pressur e
Modulato r Valv e
To Selec t Lin e Pressur e
Clutc h Pressur e Clutc
h Pressur e
Shift Solenoi d Valve s
Torque Converte r Clutc h (Lock-u p Control )
Solenoi d Valve s
Regulato r Valv e
Throttl e B Pressur e
Line Pressur e Contro l Pressur e
Lin e Pressur e Contro l Valv e
Throttl e Valv e
1-2 Shif t Valv e
2- 3 Shif t Valv e
3- 4 Shif t Valv e
Modulato r Pressur e
ATF Pum p Regulator Valv e
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Position

As the engine turns, the ATF pump also starts to operate. Automatic transmission fluid (ATF) is drawn from (99) and dis-

charged into (1). Then, ATF flowing from the ATF pump becomes the line pressure (1). The line pressure (1) is regulated

by the regulator valve. The torque converter inlet pressure (92) enters (94) of the torque converter through the lock-up

shift valve and discharges into (90). The torque converter check valve prevents the torque converter pressure from rising.

Under this condition, the hydraulic pressure is not applied to the clutches as the manual valve stops line pressure (1).

NOTE:

• When used, "left" or "right" indicates direction on the hydraulic circuit.

• The hydraulic circuit is for '96 - '98 models. On '99 - 01 models, the 2nd accumulator is different.ProCarManuals.com

Hydraulic Flo w (cont'd )
Position
The lin e pressur e (1 ) flow s t o th e manua l valve , th e modulator valve, th e lin e pressur e contro l valv e an d th e throttl e valve .
Th e lin e pressur e (1 ) become s th e modulato r pressur e (6 ) a t th e modulato r valve , an d th e lin e pressur e (4 ) an d (7) , an d th e
1st-hol d clutc h pressur e (70 ) a t th e manua l valve . Th e modulato r pressur e (6 ) flow s t o th e 1- 2 shif t valve , th e 2- 3 shif t
valve an d th e 3- 4 shif t valv e becaus e th e shif t solenoi d valv e A is turne d OF F an d B is turne d O N b y th e PCM , an d th e 1- 2
shif t valv e is move d t o th e righ t side . Th e lin e pressur e (4 ) becomes the 1s t clutc h pressur e (10 ) a t th e 1- 2 shif t valve . Th e
1s t clutc h pressur e (10 ) i s applie d t o th e 1s t clutch , an d th e 1s t clutc h i s engaged . Th e lin e pressur e (7 ) become s th e 1st -
hol d clutc h pressur e (70 ) a t th e 1- 2 shif t valve . Th e Ist-hol d clutc h pressur e (70 ) i s applie d t o th e 1st-hol d clutch , an d th e
1st-hol d clutc h i s engaged .
Powe r i s transmitte d onl y durin g deceleratio n throug h th e 1st-hol d clutch .
NOTE:
• Whe n used , "left " o r "right " indicate s directio n o n th e hydrauli c circuit .
• Th e hydrauli c circui t i s fo r '9 6 - '9 8 models . O n '9 9 - 0 1 models , th e 2n d accumulato r i s different .
Descriptio n
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Position

The line pressure (1) flows to the manual valve, the modulator valve, the line pressure control valve and the throttle valve.

The line pressure (1) becomes the modulator pressure (6) at the modulator valve, the line pressure (4) and the 1st-hold

clutch pressure (70) at the manual valve. The modulator pressure (6) does not flow to each shift valve because shift

solenoid valves A and B are turned ON by the PCM. The line pressure (4) passes through the 1-2 shift valve and the 2-3

shift valve, then changes to the 2nd clutch pressure (20) at the orifice. The 2nd clutch pressure (20) is applied to the 2nd

clutch, and the 2nd clutch is engaged. The 1st-hold clutch pressure (70) passes through the 1-2 shift valve, then goes to

the 1st-hold clutch. The 1st-hold clutch is engaged. Power is transmitted only during deceleration through the 1st-hold

clutch.

NOTE:

• When used, "left" or "right" indicates direction on the hydraulic circuit.

• The hydraulic circuit is for '96 - '98 models. On '99 - 01 models, the 2nd accumulator is different.ProCarManuals.com