1995 ACURA TL brake sensor

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

Component Locations

ABS CONTROL UNIT

UNDER-DASH RELAY BOX

RIGHT-FRONT WHEEL

SENSOR CONNECTOR

UNDER-HOOD

FUSE/RELAY BOX
SERVICE CHECK CONNECTOR (2P)

ABS INSPECTION CONNECTOR (6P)

MODULATOR UNIT

UNDER-HOOD ABS

FUSE/RELAY BOX
RIGHT-REAR WHEEL SENSOR

RIGHT-REAR WHEEL

SENSOR CONNECTOR

LEFT-REAR

WHEEL SENSOR

LEFT-REAR WHEEL

SENSOR CONNECTOR

RIGHT-FRONT

WHEEL SENSOR
LEFT FRONT WHEEL

SENSOR CONNECTOR
PARKING BRAKE SWITCH

UNDER-DASH FUSE/RELAY BOX

LEFT-FRONT WHEEL SENSORProCarManuals.com

Component Locations

RIGHT-REAR WHEEL SENSOR

SERVICE CHECK CONNECTOR (2P)

ABS CONTROL UNIT
RIGHT-REAR WHEEL

SENSOR CONNECTOR

UNDER-DASH RELAY BOX

RIGHT-FRONT WHEEL

SENSOR CONNECTOR

UNDER-HOOD

FUSE/RELAY BOX

LEFT-REAR

WHEEL SENSOR

MODULATOR UNIT

UNDER-HOOD ABS

FUSE/RELAY BOX
LEFT-REAR WHEEL

SENSOR CONNECTOR

PARKING BRAKE SWITCH

UNDER-DASH FUSE/RELAY BOX

RIGHT-FRONT

WHEEL SENSOR

LEFT-FRONT WHEEL SENSOR
LEFT-FRONT WHEEL

SENSOR CONNECTORProCarManuals.com

Safety Indicato r
Componen t Locatio n Inde x
SRS component s ar e locate d in thi s area . Revie w th e SR S componen t locations , precautions , an d procedure s i n th e SR S
( sectio n 24 ) befor e performin g repair s o r service .
SAFETY INDICATO R
Troubleshooting , pag e 23-13 8
Inpu t Test , pag e 23-13 9
Bul b Replacement , pag e 23-13 8
CEILIN G LIGH T
Test/Replacement , pag e 23-17 8
FRON T PASSENGER' S DOO R SWITC H
Test , pag e 23-18 0
RIGH T REA R DOO R SWITC H
Test , pag e 23-18 0
BRAK E SWITC H
Test , pag e 23-18 4
Peda l Heigh t Adjustment ,
sectio n 1 9 HIG
H MOUN T BRAK E LIGH T
Bul b Replacement , pag e 23-18 4
TRUN K LIGH T
Test , pag e 23-18 1
DRIVER' S DOO R SWITC H
Test , pag e 23-18 0
LEFT REA R DOO R SWITC H
Test , pag e 23-18 0 TRUN
K LATC H SWITC H
Test/Replacement , pag e 23-18 1
BRAKE LIGH TFAILUR E SENSO R
Test , pag e 23-14 1
Descriptio n
Safety Indicato r System :
Bulb s ar e use d to indicat e whe n th e trun k li d o r a doo r i s no t full y closed , o r whe n a brak e ligh t i s faulty . Th e bulb s wil l remai n
O N fo r abou t tw o second s afte r th e ignitio n switc h ha s bee n turne d O N (II ) t o sho w tha t th e syste m circui t i s functioning .
Brak e Ligh t Bul b Failur e Indicator :
I f al l brak e ligh t bulb s ar e OK , th e indicato r ligh t stay s of f becaus e th e WHT/GR N wir e i s constantl y bein g grounde d b y th e
brak e ligh t failur e sensor . Wit h th e brak e ligh t off , th e ground is provide d throug h th e diode , th e failur e senso r rela y coil , an d
the bul b filaments . Wit h th e brak e ligh t on , bot h relay s in th e sensor , connecte d in series , suppl y ground . I f eithe r o f th e tw o
bulb s is no t working , th e chai n is broke n an d th e WHT/GR N wir e is no t bein g grounded . Th e indicato r ligh t come s on .
SPOTLIGH T
Test/Replacement ,
pag e 23-17 7
ProCarManuals.com

Safety Indicator

Indicator Input Test (cont'd)

CONNECTOR "B" (C613): WIRE SIDE OF FEMALE TERMINALS

Trml Wire
Test condition
Test: Desired result
Possible cause if result is not obtained

B15

B16
ORN1

GRN/WHT
Trunk lid open

Right rear door open
Check for continuity to ground:

There should be continuity.

NOTE: Before testing, remove the

No. 37 (15 A) fuse from the

under-hood fuse/relay box.

Check for continuity to ground:

There should be continuity.

NOTE: Before testing, remove the

No. 37 (15 A) fuse from the

under-hood fuse/relay box.
• Faulty trunk latch switch

• An open in the wire

• Faulty door switch

• An open in the wire

CONNECTOR "C" (C614): WIRE SIDE OF FEMALE TERMINALS

Trml Wire
Test condition
Test: Desired result
Possible cause if result is not obtained

C1

C2

C3

C4

C5

C12
WHT/GRN

GRN/BLU

GRN/YEL

GRN/RED

BLK/WHT

BLK
Brake pedal pushed

Driver's door open

Left rear door open

Front passenger's door

open

Ceiling light switch in

middle position

Under all conditions
Check for continuity to ground:

There should be less than 200 ohms

with the pedal pushed.

Check for continuity to ground:

There should be continuity.

NOTE: Before testing, remove the

No. 37 (15 A) fuse from the

under-hood fuse/relay box.

Connect to ground: The ceiling

light should come on.

Check for continuity to ground:

There should be continuity.
• Blown No. 30 (20 A) fuse in the

under-dash fuse/relay box

• Faulty brake switch

• Blown brake light bulbs

• Faulty brake light failure sensor

• Poor ground (G502)

• An open in the wire

• Faulty door switch

• An open in the wire

• Blown No. 37 (15 A) fuse in the

under-hood fuse/relay box

• Faulty ceiling light

• An open in the wire

• Poor ground (G401, G404)

• An open in the wireProCarManuals.com

Brake Ligh t Failur e Senso r Tes t
1. Firs t mak e sur e th e brak e light s com e o n whe n th e
brak e peda l i s pressed .
I f al l th e brak e light s com e on , g o t o ste p 2 .
I f on e o f th e brak e light s doe s no t com e on , chec k
whethe r th e bul b i s blown . I f th e bul b is OK , g o t o
ste p 2 .
I f non e o f th e brak e light s com e on , chec k th e
brak e ligh t circui t.
2 . Ope n th e trun k lid , an d pul l bac k th e lef t trun k sid e
tri m to uncove r th e failur e sensor .
3.
LEF T TAILLIGH T
FAILURESENSOR
LEFT TRUN K SID ETRIM
WIR E SID E O F FEMAL E TERMINAL S
Make sur e th e ligh t i n th e safet y
indicato r doe s no t com e o n an d sta y o n whe n th e
No . 1 termina l o f th e 6 P connecto r i s grounde d an d
th e ignitio n switc h is turne d fro m OF F to O N (II) .
If th e ligh t come s o n an d stay s on ,
chec k fo r a n ope n i n th e WHT/GR N wir e betwee n
th e safet y indicato r an d th e No . 1 termina l o f th e
failur e sensor , an d whethe r th e safet y indicato r
circui t (printe d circui t board ) ha s a problem .
If th e ligh t doe s no t sta y on , g o t o
ste p 5 .
4. Mak e sur e th e ligh t doe s no t com e o n
whe n th e ignitio n switc h i s turne d fro m OF F t o O N
(II ) wit h th e No . 2 termina l of the 6 P connecto r
grounde d an d th e brak e peda l pressed .
If th e ligh t come s o n an d stay s on ,
replac e th e failur e sensor .
If th e doe s no t sta y on , chec k fo r
a n ope n in th e BL K wir e betwee n th e No . 2 termi -
na l o f th e failur e senso r an d ground , an d chec k
fo r poo r groun d a t G502 .
ProCarManuals.com

Description

The cruise control system uses mechanically and electri-

cally operated devices to maintain vehicle speed at a

setting selected by the driver.

The cruise control unit receives command signals from

the cruise control main switch and the cruise control

set/resume/cancel switch. It receives information about

operating conditions from the brake switch, ECM, vehi-

cle speed sensor (VSS), or the A/T gear position switch.

The cruise control unit sends operational signals to the

devices that regulate the throttle position. The throttle

position maintains the selected vehicle speed.

Essentially, the control unit compares the actual speed

of the vehicle to the selected speed. Then, the control

unit uses the result of that comparison to open or close

the throttle.

The brake switch releases the system's control of the

throttle at the instant the driver depresses the brake

pedal. The switch sends an electronic signal to the con-

trol unit when the brake pedal is depressed; the control

unit responds by allowing the throttle to close. The A/T

gear position switch sends a disengage signal input to

the control unit that also allows the throttle to close.
Operation:

The cruise control system will set and automatically

maintain any speed above 25 mph (40 km/h). To set a

speed, make sure that the main switch is in the "ON"

position. After reaching the desired speed, press the set

switch. The cruise control unit will receive a set signal

and, in turn, will actuate the cruise control actuator. If

you depress the set switch is when the cruise control

system is on, the "cruise light", an indicator in the

gauge assembly, will come on. You can cancel the

cruise control system by depressing the cancel switch or

by pushing the main switch to "OFF". This removes

power to the control unit and erases the set speed from

memory. If the system is disengaged temporarily by the

brake switch or the A/T gear position switch and vehicle

speed is still above 25 mph (40 km/h), press the resume

switch. With the resume switch depressed and the set

memory retained, the vehicle will automatically return

to the previous set speed.

For gradual acceleration without depressing the acceler-

ator pedal, push the resume switch down and hold it

there until the desired speed is reached. This will send

an acceleration signal to the control unit. When the

switch is released, the system will be reprogrammed for

the new speed. To slow the vehicle down, depress the

set switch. This will send a deceleration signal to the

control unit, causing the vehicle to coast. When you

reach the desired speed, release the set switch. This will

reprogram the system for the new speed.ProCarManuals.com