sensor ACURA TL 1995 Service Repair Manual

Operation Sequence Simulated by Modes of ALB Checker

NOTE: The wheel sensors and sensor wire harnesses are not checked by the ALB checker.

Mode 1: Sends the simulated driving signal O mph (O km/h) 113 mph (180 km/h) O mph (O km/h) of each wheel to the

ABS control unit to check the system under the normal driving. There should be no kickback.

SIMULATED DRIVING SIGNAL
LEFT-FRONT
RIGHT-FRONT

LEFT-REAR
RIGHT-REAR

Mode 2: Sends the driving signal of each wheel, then sends the lock signal of the left-rear wheel to the ABS control unit to

check the system under left-rear wheel lock. There should be kickback.

SIMULATED DRIVING SIGNAL
LEFT-FRONT
RIGHT-FRONT
LEFT-REAR

RIGHT-REAR

Mode 3: Sends the driving signal of each wheel, then sends the lock signal of the right-rear wheel to the ABS control unit

to check the system under right-rear wheel lock. There should be kickback.

SIMULATED DRIVING SIGNAL
LEFT-FRONT

RIGHT-FRONT
LEFT-REAR
RIGHT-REAR

Mode 4: Sends the driving signal of each wheel, then sends the lock signal of the left-front wheel to the ABS control unit

to check the system under left-front wheel lock. There should be kickback.

SIMULATED DRIVING SIGNAL
LEFT-FRONT
RIGHT-FRONT

LEFT-REAR
RIGHT-REAR

Mode 5: Sends the driving signal of each wheel, then sends the lock signal of the right-front wheel to the ABS control unit

to check the system under right-front wheel lock. There should be kickback.

SIMULATED DRIVING SIGNAL

Inspection Points

If the ABS indicator light comes on and the system stops during the inspection, confirm the DTC and perform the appro-

priate troubleshooting for the code.

If there is no kickback in modes 2 through 5, and the ABS indicator light does not come on, the following items are proba-

ble causes:

Pressure switch stuck ON

Clogged or stuck solenoid outlet valve

Modulator wire harness connectors improperly connectedProCarManuals.com

Electronic Component sPulsers/Whee l Sensor s
Relay Inspectio n
1. Remov e th e fail-saf e relay s an d moto r rela y (loca -
tion : se e pag e 19-46 ).
2 . Chec k fo r continuit y betwee n th e terminal s C an d D .
Ther e shoul d b e continuity .
3 . Chec k fo r continuit y betwee n th e terminal s A an d B .
Ther e shoul d b e continuit y whe n th e batter y i s con -
necte d betwee n th e terminal s C an d D . Ther e shoul d
b e n o continuit y whe n th e batter y is disconnected .
Fail-safe Relay :
Inspectio n
Motor Relay :
1. Chec k th e fron t an d rea r pulse r fo r chippe d o r dam -
age d teeth .
Front :
FRON T WHEE L SENSO R
FRON T PULSE R
Rear:
1. Chec k th e rea r pulse r fo r chippe d o r damage d teeth .
REAR PULSE R
REA R WHEE L SENSO R
2. Measur e th e ai r ga p betwee n th e whee l senso r an d
pulse r al l th e wa y aroun d whil e rotatin g th e hu b
bearin g uni t b y hand .
Standard : 0. 4 - 1. 0 m m (0.0 2 - 0.0 4 in )
NOTE : I f th e ga p exceed s 1. 0 m m (0.0 4 in) , th e proba -
bilit y is a distorte d knuckl e whic h shoul d b e replaced .
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Wheel Senso r Replacemen t
NOTE:
Be carefu l whe n installin g th e sensor s t o avoi d twistin g th e wires .
Afte r senso r replacement , confir m prope r operatio n (se e pag e 19-112 ).
Front :
6 x 1. 0 m m9.8 N- m (1. 0 kgf-m , 7 Ibf-ft )
6 x 1. 0 m m9.8 N- m (1. 0 kgf-m , 7 Ibf-ft )
8 x 1.2 5 mm22 N- m (2. 2 kgf-m , 1 6 Ibf-ft )
FRON T WHEE L SENSO R
Rear:
8 x 1.2 5 mm22 N- m (2. 2 kgf-m , 1 6 Ibf-ft )
6 x 1. 0 m m9.8 N- m (1. 0 kgf-m , 7 Ibf-ft )
REA R WHEE L SENSO R
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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

Operation

ABS Control Unit

Main Control

The ABS control unit detects the wheel speed based on the wheel sensor signal it received, then it calculates the vehicle

speed based on the detected wheel speed. The control unit detects the vehicle speed during deceleration based on the

rate of deceleration.

The ABS control unit calculates the slip rate of each wheel, and it transmits the control signal to the modulator unit

solenoid valve when the slip rate is high.

The pressure reduction control is a three-mode system, that is pressure reduction, pressure retaining and pressure intensi-

fying modes.

ABS CONTROL UNIT

Self-diagnosis Function

The ABS control unit is equipped with a main CPU and a sub CPU, and the CPUs check each other.

The CPUs check the circuit of the system.

The
self-diagnosis
can be
classified
into
two
categories.

Initial diagnosis

Regular diagnosis

On-board Diagnosis Function

The ABS control unit is connected to the data link connector.

The ABS system can be diagnosed with the Honda PGM Tester.ProCarManuals.com

Wheel Speed and Modulator Control

When the wheel speed drops sharply below the vehicle speed, the inlet valve closes to retain the caliper fluid pressure.

When the wheel speed drops further, the outlet valve opens momentarily to reduce the caliper fluid pressure. The pump

motor starts at this time.

As the wheel speed is restored, the inlet valve opens momentarily to increase the caliper fluid pressure.

Wheel Sensor

The wheel sensors are the magnetic contactless type.

As the gear pulser teeth rotate past the wheel sensor's magnetic coil, AC current is generated. The AC frequency changes

in accordance with the wheel speed. The ABS control unit detects the wheel sensor signal frequency and thereby detects

the wheel speed.

There are four wheel sensors, one for each wheel.

The gear pulser has 50 teeth.

GEAR PULSER

WHEEL SENSORProCarManuals.com

ABS Contro l Uni t
Pulsers/Whee l
Sensors
Replacemen t
1. Remov e th e glov e bo x (se e sectio n 20 ).
2 . Remov e th e fou r mountin g bolt s o f th e AB S contro l
uni t moun t bracket .
'97 AB S CONTRO L UNI TRADIATO R FA N CONTRO L '9 8 AB S CONTRO L UNI T isMODUL E CONNECTO R behin d th e moun t bracke t
3.
4 .
5.
6.
AB S CONTRO L UNI TCONNECTOR S
ABS CONTRO L UNI TMOUN T BRACKE T
Move th e bracke t forward , an d disconnec t th e eac h
connector s fro m th e bracket .
Disconnec t th e AB S contro l uni t connector s an d
radiato r fa n contro l modul e connector .
Mov e th e bracke t dow n to remov e it fro m th e car .
Remov e th e radiato r fa n contro l modul e an d thre e
AB S contro l uni t mountin g bolts .
'97 AB S CONTRO L UNI T
ABS CONTRO L UNI TMOUN T BRACKE T
RADIATO R FA N
CONTRO L MODUL E
ABS CONTRO L UNI TMOUNTIN G BOLT S9.8 N- m (1. 0 kgf-m , 7 Ibf-ft )
7. Remov e th e AB S contro l uni t fro m th e bracket .
8 . Instal l th e AB S contro l uni t i n th e revers e orde r o f
removal .
Inspectio n
1. Chec k th e fron t an d rea r pulse r fo r chippe d o r dam -
age d teeth .
2 . Measur e th e ai r ga p betwee n th e whee l senso r an d
pulse r al l th e wa y aroun d whil e rotatin g th e pulser .
Standard : 0. 4 - 1. 0 m m (0.0 2 - 0.0 4 in )
NOTE : I f th e ga p exceed s 1. 0 m m (0.0 4 in) , th e
probabilit y i s a distorte d suspensio n ar m whic h
shoul d b e replaced .
Front/Rea r
0.4- 1.0 m m(0.0 2 - 0.04 in)
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Pulsers/Wheel Sensor

Wheel Sensor Replacement

NOTE: Be careful when installing the sensors to avoid twisting the wires.

Front

6 x 1.0 mm

9.8 N-m (1.0 kgf-m, 7 Ibf-ft)
6 x 1.0 mm

9.8 N-m (1.0 kgf-m, 7 Ibf-ft)

8 x
1.25
mm

22 N-m (2.2 kgf-m, 16 Ibf-ft)

WHEEL SENSOR

Rear

6 x 1.0 mm

9.8 N-m (1.0 kgf-m, 7 Ibf-ft)

8 x
1.25
mm

22 N-m (2.2 kgf-m, 16 Ibf-ft)
WHEEL SENSORProCarManuals.com

Troubleshooting
Self-diagnosis Functio n
The climat e contro l uni t ha s a self-diagnosi s function .
Runnin g th e Self-diagnosi s Functio n
Tur n th e ignitio n switc h O N (II) , the n pres s bot h th e AUT O an d OF F button s a t th e sam e time . Whil e th e button s ar e
pressed , indicato r light s A , B , C , D , E an d F respectivel y wil l com e o n to indicat e a fault y component .
AUTO BUTTO NOFF BUTTO N
A
B
C
D
E
F
Indicator
ON
OF F
Componen t wit h proble m
In-car temperatur e senso r
Outsid e ai r temperatur e senso r
Sunligh t senso r
Evaporato r temperatur e senso r
Ai r mi x contro l moto r
Blowe r moto r Possibl
e caus e
Fault y sensor , ope n o r shor t circui t
Fault y sensor , ope n o r shor t circui t
Fault y sensor , ope n o r shor t circui t
Fault y sensor , ope n o r shor t circui t
Ope n o r shor t circuit , obstructe d door ,
fault y moto r
Ope n o r shor t circuit , fault y moto r Se
e pag e22-1 2
22-1 4
22-16
22-1 8
22-2 0
22-22 or 22- 24
(2.5L),
NOTE : I n cas e o f multipl e problems , th e respectiv e indicato r light s wil l com e on . I f indicato r light s A , B , C , D , an d E com e
o n a t th e sam e time , ther e ma y b e a n ope n in th e commo n groun d wir e o f th e sensors .
Resettin g th e Self-diagnosi s Functio n
Turnin g th e ignitio n switc h OF F wil l cance l th e self-diagnosi s function . Afte r servic e work , ru n th e self-diagnosi s functio n
onc e agai n to chec k tha t ther e is n o othe r problem.
D E F A, B , C
22-6a (3.2L)
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Outside Ai r Temperatur e Senso r
Replacemen t
1. Disconnec t th e 2 P connecto r fro m th e outsid e ai r
temperatur e sensor .
2 . Releas e th e lock , an d remov e th e outsid e ai r tem -
peratur e sensor .
OUTSID E AI R TEMPERATUR E SENSO R
LOCK
3. Instal l i n th e revers e orde r o f removal .
Test
Compar e th e resistanc e readin g betwee n th e No . 1 an d
No . 2 terminal s o f th e outsid e ai r temperatur e senso r wit h
th e specification s show n i n followin g graph ; resistanc e
shoul d b e withi n specifications .
NOTE : Di p th e senso r i n ic e water , an d measur e resis -
tance . The n pou r ho t wate r o n th e sensor , an d chec k fo r
chang e in resistance .
CAUTION : Th e senso r use s a thermisto r whic h ca n b e
damage d i f hig h curren t i s applie d durin g testing .
Therefore , us e a circui t teste r wit h a n outpu t o f 1 m A o r
les s a t th e 2 0 k range .
OUTSIDE AI R TEMPERATUR E SENSO R
TEMPERATUR E
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