sensor ACURA TL 1995 Service Manual PDF

Intake Air System

System Description

The system supplies air for all engine needs. It consists of the intake air pipe, Air Cleaner (ACL), intake air duct. Throttle

Body (TB), Idle Air Control (IAC) Valve, fast idle thermo valve, and intake manifold.

A resonator in the intake air pipe provides additional silencing as air is drawn into the system.

IAB CONTROL

SOLENOID VALVE

IAB

CHECK

VALVE

IAB

CONTROL

DIAPHRAGM
From No. 4 ECU

(ECM) ('95 - 96 models: 15A,

'97-98 models: 20A)

FUSE

(in the under-dash

fuse/relay box)

From PGM-FI

MAIN RELAY

VARIOUS

SENSORS

IAB

VACUUM TANK

THROTTLE
BODY

INTAKE

AIR DUCT

ACL

INTAKE

MANIFOLD
IDLE

ADJUSTING

SCREW
FAST

IDLE

THERMO

VALVE

RESONATOR
INTAKE

AIR

PIPE
IAC VALVE

ENGINE

COOLANT
ENGINE

COOLANT

IAB

VALVE
ECMProCarManuals.com

Intake Air System

Air Cleaner (ACL)

ACL Element Replacement

NOTE: When removing the ACL housing cover, do not disconnect the hose and MAF sensor connector.

ACL HOUSING

COVER

MAF SENSOR

ACL

HOUSING
ACL ELEMENT

Normal conditions:

Replace air cleaner element every

30,000 miles (48,000 km) or 24

months whichever comes first.

Severe conditions:

Clean air cleaner element every

15,000 miles (24,000 km) or 12

months and replace every 30,000

miles (48,000 km) or 24 months

whichever comes first.ProCarManuals.com

Intake Air System

Throttle Body (cont'd)

Disassembly

IDLE ADJUSTING

SCREW

O-RING

TP

SENSORProCarManuals.com

Intake Air Bypass (IAB) Control System

Description

Two air intake paths are provided in the intake manifold to allow the selection of the intake path most favorable for a

given engine speed. Satisfactory power performance is achieved by closing and opening the intake Air Bypass (IAB)

valves. High torque at low rpm is achieved when the IAB valves are closed, whereas high power at high rpm is achieved

when the IAB valves are opened.

IAB CONTROL

DIAPHRAGM

From No. 4 ECU (ECM)

('95-96 models: 15A,

'97 - 98 models: 20A) FUSE

(In the under-dash

fuse/relay box)

VARIOUS

SENSORS

IAB

CONTROL

SOLENOID

VALVE

IAB VACUUM TANK

IAB CONTROL SOLENOID VALVE OFF

ENGINE RPM IS ABOVE 4,800 rpmProCarManuals.com

Three Way Catalytic Converter (TWC)

Description

The Three Way Catalytic Converter (TWC) and Warm Up Three Way Catalytic Converter (WU TWC) are used to convert

hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NOx) in the exhaust gas to carbon dioxide (CO2), dini-

trogen (N2) and water vapor.

PRIMARY

HEATED

OXYGEN SENSOR

(PRIMARY HO2S)
HOUSING

WARM UP

THREE WAY

CATALYST

THREE WAY

CATALYSTS

SECONDARY

HEATED

OXYGEN SENSOR

(SECONDARY

HO2S)

FRONT OF

VEHICLE
HOUSINGProCarManuals.com

Exhaust Ga s Recirculatio n (EGR ) Syste m
Descriptio n
The EG R syste m is designe d to reduc e oxide s o f nitroge n emission s (NOx ) b y recirculatin g exhaus t ga s throug h th e EG R
valv e an d th e intak e manifol d int o th e combustio n chambers . I t i s compose d o f th e EG R valve , EG R vacuu m contro l valve ,
EG R contro l solenoi d valve , EC M an d variou s sensors .
Th e EC M contain s memorie s fo r idea l EG R valv e lift s fo r varyin g operatin g conditions . Th e EG R valv e lif t senso r detect s
th e amoun t o f EG R valv e lif t an d send s th e informatio n t o th e ECM . Th e EC M the n compare s it wit h th e idea l EG R valv e lif t
whic h i s determine d b y signal s sen t fro m th e othe r sensors . I f ther e i s an y differenc e betwee n th e two , th e EC M cut s cur -
ren t t o th e EG R contro l solenoi d valv e to reduc e vacuu m applie d to th e EG R valve .
EGRVACUU MCONTRO LVALVE
EGRCONTRO L
SOLENOI D
VALVE
EGR VALV E
LIF T SENSO R Fro
m No . 4 EC U (ECM )
('9 5 - 9 6 models : 15A , '9 7 - 9 8 models : 20A )
FUS E
(i n th e under-das h fuse/rela y box )
VARIOU S
SENSOR S
EG R VALV E
INTAKE
MANIFOL D
ECM
ProCarManuals.com

'95 - 96 models:

VARIOUS

SENSORS

From

No. 4 ECU
(ECM)

(20A) FUSE

(in the under-dash

fuse/relay box)

VARIOUS

SENSORS

EVAP

TWO WAY

VALVE
EVAP

BYPASS

SOLENOID

VALVE
EVAP

THREE

WAY

VALVE
EVAP CONTROL

CANISTER

VENT SHUT VALVE
EVAP PURGE

CONTROL

SOLENOID VALVE
ECM
ECM
From

No. 4 ECU
(ECM) (15A)

FUSE (in the under-dash

fuse/relay box)

EVAP CONTROL

CANISTER
FUEL

TANK

PRESSURE

SENSOR
FUEL TANK
FUEL FILL

CAP

FUEL TANK

EVAP VALVE
FUEL TANK

'97 - 98 models:
FUEL TANK

EVAP VALVE
EVAP TWO WAY VALVE

FRESH

AIR

FUEL FILL CAP
EVAP PURGE

FLOW SWITCH
EVAP PURGE

CONTROL

SOLENOID VALVEProCarManuals.com

Description

The automatic transmission is a combination of a 3-element torque converter and a dual-shaft electronically controlled

automatic transmission which provides 4 speeds forward and 1 reverse. The entire unit is positioned in line with the engine.

Torque Converter, Gears 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 drive plate is a ring gear which meshes with the starter pinion when the engine is being started.

The entire torque converter assembly serves as a flywheel while transmitting power to the transmission mainshaft.

The transmission has two parallel shafts: the mainshaft and the countershaft. The mainshaft is in line with the engine

crankshaft.

The mainshaft includes the 1st, 2nd and 4th clutches, and gears for 4th, 2nd, 1st and reverse (3rd gear is integral with the

mainshaft, while the reverse gear is integral with 4th gear).

The countershaft includes the 3rd, and 1st-hold clutches, and gears for 3rd, 4th, 1st, 2nd, reverse, and parking. The sec-

ondary drive gear is integrated with the countershaft.

The gears on the mainshaft are in constant mesh with those on the countershaft.

When certain combinations of gears in the transmission are engaged by clutches, power is transmitted from the mainshaft

to the countershaft to provide and positions.

Electronic Control

The electronic control system consists of the Transmission Control Module (TCM), sensors, a linear solenoid and four

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

The TCM is located below the dashboard, behind the glove box on the passenger's side.

Hydraulic Control

The lower valve body assembly includes the main valve body, the servo body and the shift control solenoid valves. They

are bolted on the lower part of the transmission housing.

Other valve bodies, the regulator valve body, the ATF pump body, the 2nd accumulator body, and the throttle valve body,

are bolted to the torque converter housing.

The main valve body contains the manual valve, the 1 - 2 shift valve, the 2 - 3 shift valve, the 3 - 4 shift valve, the 4th kick-

down valve, the 2 - 3 orifice control valve, the 3 - 4 orifice control valve, the 4th exhaust valve, the servo control valve,

and the main orifice control valve.

The servo body contains the servo valve, 3rd and 4th accumulator pistons.

The regulator valve body contains the regulator valve, the lock-up shift valve, and the cooler relief valve.

Fluid from the regulator passes through the manual valve to the various control valves.

The throttle valve body includes the throttle valve which is bolted onto the 2nd accumulator body. The 2nd accumulator

piston is assembled in the 2nd accumulator body.

The linear solenoid is joined with the throttle valve body.

The ATF pump body contains the modulator valve, the lock-up control valve, the lock-up timing valve, and the relief valve.

The torque converter check valve is located in the torque converter housing under the ATF pump body.

The 1st and 1st-hold accumulator pistons are assembled in the rear cover.

The clutches receive fluid from their respective feed pipes or internal hydraulic circuit.

Shift Control Mechanism

Input from various sensors located throughout the vehicle determines which shift control solenoid valve the TCM will acti-

vate. 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.

Lock-up Mechanism

In position, in 2nd, 3rd and 4th, and in position in 3rd, pressurized fluid is drained from the back of the torque con-

verter 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 speed as the engine crankshaft. Together with hydraulic control, the TCM 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 throttle valve. When lock-up control solenoid valves A and B activate, the modulator pressure changes.

The lock-up control solenoid valves A and B are mounted on the torque converter housing, and are controlled by the TCM.ProCarManuals.com

RING GEAR

EXTENSION

SHAFT
TORQUE

CONVERTER

2ND CLUTCH

4TH CLUTCH

1ST CLUTCH

SECONDARY

DRIVEN GEAR
A/T GEAR

POSITION SWITCH
1ST-HOLD

CLUTCH
COUNTERSHAFT

SPEED SENSOR

3RD

CLUTCHProCarManuals.com

FRONT

EXTENSION

SHAFT

SECONDARY

DRIVE GEAR

SECONDARY

DRIVEN GEAR

3RD CLUTCH

COUNTERSHAFT

3RD GEAR
DRIVE PLATE/RING GEAR

TORQUE CONVERTER

COUNTERSHAFT

SPEED SENSOR

COUNTERSHAFT 2ND GEAR

COUNTERSHAFT 4TH GEAR

REVERSE SELECTOR

COUNTERSHAFT

REVERSE GEAR

PARKING GEAR

COUNTERSHAFT 1ST GEAR

ONE-WAY CLUTCH

1ST-HOLD CLUTCH
MAINSHAFT SPEED SENSOR

MAINSHAFT 3RD GEAR

MAINSHAFT 2ND GEAR

2ND CLUTCH

4TH CLUTCH

MAINSHAFT 4TH GEAR

MAINSHAFT REVERSE GEAR

MAINSHAFT 1ST GEAR

1ST CLUTCH

MAINSHAFT

COUNTERSHAFT
ATF PUMP GEARSProCarManuals.com