check engine ACURA TL 1995 Service Manual PDF

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

Description

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

solenoid valves.

Shift 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.

TCM

Linear Solenoid

Shift Control

Solenoid Valve A

Shift Control

Solenoid Valve B

Lock-up Control

Solenoid Valve A

Lock-up Control

Solenoid Valve B

Engine Speed Signal

Brake Switch Signal

Mainshaft Speed Sensor

Signal

Countershaft Speed

Sensor Signal

Vehicle Speed Sensor

Signal

Indicator Light

Self-Diagnosis Signal
Electronic Control System

Shift Control

Lock-up Control
Throttle Position

Sensor Signal

Engine Coolant

Temperature

Sensor Signal

Service Check

Connector

Barometric

Pressure Sensor

INTERLOCK

CONTROL UNIT

Self-Diagnosis

FunctionProCarManuals.com

Description

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.
Hydraulic Flow (cont'd)ProCarManuals.com

8.
Set the control shaft to the position, then install

the A/T gear position switch on the control shaft

and install the clamp on the rear cover.

SHIFT CABLE

CONTROL

LEVER

9. Connect the A/T gear position switch connector,

then install the harness stay.

10. Turn the ignition switch ON (II). Move the shift lever

through all gears, and check the A/T gear position

switch synchronization with the A/T gear position

indicator.

11. If the A/T gear position switch does not synchronize

with the A/T gear position indicator, loosen the

bolts securing the A/T gear position switch and

adjust the A/T gear position switch installation.

GAUGE ASSEMBLY

A/T GEAR

POSITION INDICATOR
12. Install the A/T gear position switch cover. Tighten

the bolt on the ATF pan side loosely so that there is

no clearance between the A/T gear position switch

cover and the ATF pan. Then tighten the bolt on the

rear cover side to the specified torque, and tighten

the bolt on the ATF pan side to the specified torque.

6 x 1.0 mm

(Rear cover side)

12 N-m (1.2 kgf-m,

8.7 Ibf-ft)

A/T GEAR POSITION

SWITCH COVER
ATF PAN

6 x 1.0 mm (ATF pan side)

12 N-m (1.2 kgf-m, 8.7 Ibf-ft)

13. Start the engine. Move the shift lever through all

gears, and verify the following:

• The shift lever cannot be moved to the posi-

tion from the position without pushing the

shift lever.

• The engine will not start in any gear, only in the

or position.

• The back-up lights come on when the shift lever

is in the position.ProCarManuals.com

Position

Upshift

Downshift

4. Accelerate to about 35 mph (57 km/h) so the transmission is in 4th, then shift from position to position. The

vehicle should immediately begin slowing down from engine braking.

CAUTION: Do not shift from

age the transmission.
or position to or position at speeds over 63 mph (100 km/h); you may dam-

5. Check for abnormal noise and clutch slippage in the following positions.

(1st Gear) Position

a. Accelerate from a stop at full throttle. Check that there is no abnormal noise or clutch slippage,

b. Upshifts should not occur with the selector in this position.

(2nd Gear) Position

a. 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 position.

(Reverse) Position

Accelerate from a stop at full throttle, and check for abnormal noise and clutch slippage.

6. Test in (Parking) Position

Park the vehicle on slope (approx. 16°), apply the parking brake, and shift into position. Release the brake; the vehi-

cle should not move.ProCarManuals.com

Fluid Leve l
Checking/Changin g
Checking
NOTE : Chec k th e flui d leve l wit h th e engin e a t norma l
operatin g temperatur e (th e radiato r fa n come s on) .
1 . Par k th e vehicl e o n leve l ground . Tur n of f th e engine .
2 . Remov e th e dipstic k (yello w loop ) fro m th e trans -
mission , an d wip e i t wit h a clea n cloth .
DIPSTIC KGUIDE
3.
4 .
DIPSTIC K (YELLO W LOOP )
Insert th e dipstic k int o th e transmission . Mak e sur e
th e notc h i n th e rubbe r ca p fit s i n th e dipstic k guid e
an d pus h th e dipstic k i n al l th e way .
Remov e th e dipstic k an d chec k th e flui d level . I t
shoul d b e betwee n th e uppe r an d lowe r marks .
5.
6 .
UPPE R MAR KLOWE R MAR K
It th e leve l i s belo w th e lowe r mark , pou r th e recom -
mended fluid * int o th e tub e t o brin g i t t o th e uppe r
mark.
Inser t th e dipstic k bac k i n th e transmission . Mak e
sur e th e notc h fit s i n th e dipstic k guid e an d th e dip -
stic k i s dow n al l th e way . Changin
g
1 . Brin g th e transmissio n u p t o norma l operatin g tem -
peratur e (th e radiato r fa n come s on ) b y drivin g th e
vehicle . Par k th e vehicl e o n leve l ground , tur n th e
engin e off , an d remov e drai n plug .
NOTE : I f a coole r flushe r i s t o b e used , se e pag e
14-19 3 an d 14-194 .
2. Reinstal l th e drai n plu g wit h a ne w sealin g washer ,
the n refil l th e transmissio n wit h th e recommende d
fluid * t o th e uppe r mar k o n th e dipstick .
Automati c Transmissio n Flui d Capacity :
2. 7 (2. 9 U S qt. , 2. 4 Im p qt. ) a t chang e
7.2 (7. 6 U S qt. , 6. 3 Im p qt. ) a t overhau l
Recommende d Automati c Transmissio n Fluid :
Genuin e Hond a Premiu m Formul a Automati c
Transmissio n Flui d (ATF) *
DRAIN PLU G18 x 1. 5 m m49 N- m (5. 0 kgf-m , 3 6 Ibf-ft )
SEALIN G WASHE R
Replace .
Always us e Genuin e Hond a Premiu m Formul a
Automati c Transmissio n Flui d (ATF) . Usin g a non -
Hond a AT F ca n affec t shif t quality .
ProCarManuals.com

Steering Gearbo x
Installatio n (cont'd )
11. Reconnec t th e tw o line s an d tw o hose s t o th e valv e
body unit .
NOTE :
• Chec k th e hos e band s an d cli p fo r deformatio n
an d deterioration , an d replac e the n if necessary .
• Afte r installin g th e steerin g gearbox , mak e sur e
tha t ther e is n o interferenc e betwee n th e cylinde r
line s an d rea r beam .
PUMP OUTLE T LIN EFrom th e pum p
12 N- m (1. 2 kgf-m ,9 Ibf-ft )
VALV E BOD Y UNI T
11 N- m (1. 1 kgf-m ,8 Ibf-ft )
12. Reconnec t th e tie-ro d end s t o th e steerin g knuckles ,
tighte n th e castl e nu t t o th e specifie d torque , an d
instal l ne w cotte r pins .
NOTE : Befor e connectin g th e tie-ro d ends , chec k
th e bal l join t pi n tapere d sectio n an d thread s sectio n
fo r greas e contamination , an d wip e it i f necessary .
CAUTION : Torqu e th e castl e nu t t o th e lowe r torqu e
specification , the n tighte n it onl y fa r enoug h t o alig n
th e slo t wit h th e pi n hole . D o no t alig n th e nu t b y
loosening . COTTER PI NCASTL E NU T Replace.49 - 5 9 N- m O n reassembly , ben d(5.0 - 6. 0 kgf-m , 3 6 - 4 3 Ibf-ft ) th e cotte r pi n a s shown .
13. Instal l th e fron t wheels .
14 . Fil l th e syste m wit h powe r steerin g flui d an d blee d
ai r fro m th e syste m (se e pag e 17-24 ).
15 . Afte r installation , perfor m th e followin g checks .
• Star t th e engine , allo w i t t o idle , an d tur n th e
steerin g whee l fro m lock-to-loc k severa l time s t o
war m u p th e fluid . Chec k th e gearbo x fo r leak s
(se e pag e 17-26 ).
• Adjus t th e fron t to e (se e sectio n 18 ).
• Chec k th e steerin g whee l spok e angle . Adjus t b y
turnin g th e righ t an d lef t tie-rods , i f necessary .
NOTE : Tur n th e righ t an d lef t tie-rod s equally .
SENSO R RETUR N LIN ETo th e reservoi rRETURN HOS ETo th e reservoi r
ProCarManuals.com

Brake Booster

Inspection

Functional Test

1. With the engine stopped, depress the brake pedal

several times to deplete the vacuum reservoir, then

depress the pedal hard and hold it for 15 seconds. If

the pedal sinks, either the master cylinder is

bypassing internally, or the brake system (master

cylinder, lines, modulator, proportioning valve, or

caliper) is leaking.

2. Start the engine with the pedal depressed. If the

pedal sinks slightly, the vacuum booster is operat-

ing normally. If the pedal height does not vary, the

booster or check valve is faulty.

3. With the engine running, depress the brake pedal

lightly. Apply just enough pressure to hold back

automatic transmission creep. If the brake pedal

sinks more than 25 mm (1.0 in.) in three minutes, the

master cylinder is faulty. A slight change in pedal

height when the A/C compressor cycles on and off if

normal. (The A/C compressor load changes the vac-

uum available to the booster.)

Leak Test

1. Depress the brake pedal with the engine running,

then stop the engine. If the pedal height does not

vary while depressed for 30 seconds, the vacuum

booster is OK. If the pedal rises, the booster is faulty.

2. With the engine stopped, depress the brake pedal

several times using normal pressure. When the

pedal is first depressed, it should be low. On consec-

utive applications, the pedal height should gradually

rise. If the pedal position does not vary, check the

booster check valve.ProCarManuals.com

Booster Check Valve Test ('95, '96 models)

1.

2.
Disconnect the brake booster vacuum hose at the

booster or at the booster side of the valve.

Start the engine and let it idle. There should be vac-

uum. If no vacuum is available, the check valve is

not working properly. Replace the check valve and

retest.

CHECK VALVE

VACUUM HOSE

Booster Check Valve Test ('97 - 98 models)

1. Disconnect the brake booster vacuum hose at the

booster.

2. Start the engine and let it idle. There should be vac-

uum. If no vacuum is available, the check valve is

not working properly. Replace the brake booster

vacuum hose and check valve, and retest.

BRAKE BOOSTER

VACUUM HOSE

(Check valve

built-in)

VACUUM HOSEProCarManuals.com

Pump motor control:

The ABS control unit monitors the brake fluid pressure in the accumulator by the pressure switch ON/OFF signals. The

ABS control unit turns the pump on when the pressure in the accumulator drops, and stops the pump when the pressure

rises to the specified value.

If the pressure does not reach the specified value after the motor has operated continuously for a specified period, the

ABS control unit stops the motor and activates the ABS indicator light.

Self-diagnosis function:

The self-diagnosis function, provided in the sub-function of the ABS control unit, monitors the main system functions by

constantly transmitting the data between the two Central Processing Units (CPUs). When an abnormality is detected, the

ABS control unit turns the ABS indicator light on and stops the ABS, although the basic brake system continues to operate

normally.

When the ABS control unit detects an abnormality with the ABS and turns the ABS indicator light on, the diagnostic trou-

ble code (DTC), which shows the problem part or unit, is recorded in the control unit. The DTC can be read by the blinking

frequency of the ABS indicator light.

Fail-safe function:

When an abnormality is detected in the ABS control sys-

tem self-diagnosis, the solenoid operations are suspend-

ed by turning off the two fail-safe relays. This discon-

nects the ground circuits of all the solenoid valves to

prevent ABS operation.

Under these conditions, the braking system functions

just as an ordinary one.

Fail-safe relay:

The fail-safe relay's terminal side contact is normally

open. When there is continuity at the relay coil, the fail-

safe relay is closed, thereby connecting the ground cir-

cuit to the solenoid valve.

ABS indicator light:
SOLENOID VALVE

BAT

REAR FAIL-SAFE RELAY

FRONT FAIL-SAFE RELAY

The ABS control unit turns the ABS indicator light on when one or more of the following abnormalities are detected. This

is only a partial list.

When the operating time of the motor in the power unit exceeds the specified period.

When vehicle running time exceeds 30 seconds without releasing the parking brake.

When absence of speed signals from any of the four wheel sensor is detected.

When the activation time of all solenoids exceeds a given time, or an open circuit is detected in the solenoid system.

When solenoid output is not detected in the simulated ABS operation when the engine is started or the vehicle is driven.

To check the indicator light bulb, the light is activated when the ignition switch is first turned on. The light goes off after

the engine is started if there is no abnormality in the system.
ABS CONTROL UNITProCarManuals.com