1996 ACURA RL KA9 wheel

Troubleshooting Precautions

ABS Indicator Light:

The ABS indicator light comes on for 3 seconds and then goes off when the control unit detects no problem during the ini-

tial diagnosis right after the engine starts. However, the ABS indicator light can stay on for up to 40 seconds when the

control unit starts to check for pump overrun, etc. during the initial diagnosis. The ABS indicator light comes on, and the

ABS control unit memorizes the diagnostic trouble code (DTC) under certain conditions.

The parking brake is applied for more than 30 seconds while the vehicle is being driven. (DTC 2-1)

The transmission downshifted excessively. (DTC 4-1, 4-2)

The vehicle loses traction, and the front wheels spin for more than 1 minute when starting from a stuck condition on a

muddy, snowy, or sandy road. (DTC 4-8)

Tire adhesion is lost due to excessive cornering speed. (DTC 5, 5-4, 5-8)

The vehicle is driven on an extremely rough road. (DTC 8-1)

The vehicle is interfered by strong radio waves (noise), for example, illegal radio, etc. (DTC 8-2)

NOTE: If there is any trouble in the system, the ABS indicator light comes on during driving.

Diagnostic Trouble Code (DTC):

When the control unit detects a problem and the ABS indicator light comes on, the control unit memorizes the DTC.

The control unit has three memory registers. When a problem occurs, the control unit stores the DTC in the first memory

register. If another problem occurs, or the same problem occurs again, the control unit moves the first DTC to the next

memory register, and stores the second DTC in the first register. If there's a third problem occurrence, the two existing

DTCs are moved up one register, and the third DTC is stored in the first register. If problems continue to occur, the oldest

problem is moved out of the last register and lost, and the most recent problem is stored in the first register. When the

same problem occurs three times, the same DTC is stored in all memory registers. (Refer to the Symptom-to-System

Chart for diagnostic period.)

The most recent DTC is indicated first, and the oldest DTC is indicated last.

The DTCs are erased from the control unit when the ABS control unit +B2 power supply or connector is disconnected.

The control unit's memory can be erased by disconnecting the ABS B2 fuse for more than 3 seconds.

Self-diagnosis:

There are three self-diagnoses described below.

Initial diagnosis: Performed right after the engine starts until the ABS indicator light goes off.

Regular diagnosis: Continuously performed (under some conditions) after the ABS indicator light goes off until the

engine stops.

Individual part/system diagnosis: Diagnosis about a specific part/system under its operating conditions.

The CPU (central processing unit) controls the following when it detects a problem during self-diagnosis:

Turns the ABS indicator light ON.

Turns the front and rear fail-safe relays off.

Stops the ABS control.

Stops the ABS pump. (The pump may work under some conditions.)

After the DTC is stored in the control unit, the CPU stops self-diagnosis.ProCarManuals.com

DTC 4- 1 (Right-front) , 4- 2 (Left-front) , 4- 4 (Right-rear) , 4- 8 (Left-rear) :
Whee l Senso r
The AB S contro l uni t monitor s th e whee l senso r signa l durin g th e regula r diagnosi s (a t speed s o f 6 mp h (1 0 km/h ) o r
more) . Thi s diagnosi s i s no t performe d whe n th e parkin g brak e signa l i s ON . Th e AB S contro l uni t turn s th e AB S indicator
ligh t o n i f i t detect s tha t ther e i s n o whee l senso r signa l fro m th e wheel .
Possibl e causes :
Open circuit , interna l shor t o r shor t t o bod y groun d in th e whee l senso r
Ope n circui t o r shor t t o bod y groun d in th e positiv e (+ ) wir e betwee n th e whee l senso r an d AB S contro l uni t
Ope n circui t o r shor t t o bod y groun d i n th e negativ e (- ) wir e betwee n th e whee l senso r an d AB S contro l uni t
Positiv e (+ ) wir e shorte d t o th e negativ e (- ) wir e betwee n th e whee l senso r an d AB S contro l uni t
Loos e connecto r o r poo r contac t o f terminal s
Improper whee l senso r ai r ga p
Fault y AB S contro l uni t
Missin g o r damage d pulse r
Modulato r doe s no t decreas e pressur e properl y
Whee l loc k b y downshif t
Is th e resistanc e a s specified ?— Front : 700-1,10 0— Rear : 1,400-2,00 0
Chec k th e continuit y o f th e whee l
sensor :Check fo r continuit y betwee n th e
appropriat e whee l senso r 2 P con -
necto r termina l No . 2 an d bod y
ground .
Is ther e continuity ?
(To pag e 19-66 )
WHEE L SENSO R 2P CONNECTO R
DTC4-14- 24- 44-8
Appropriat e Whee l Senso rRight-fron tLeft-frontRight-rea rLeft-rear
Wire sid e o f femal e terminal s
Replac e th e appropriat e whee l
sensor .
Replac e th e appropriat e whee lsensor .
When vehicl e is driven , ABS
indicato r ligh t i s ON .
Wit h th e SC S servic e connec -
to r connecte d (se e pag e 19-40 ),
DTC s 4-1 , 4-2 , 4- 4 and/o r 4- 8
ar e indicated .
Chec k th e whee l senso r resis -
tance :
1 . Disconnec t th e appropriat e
whee l sensor * 2 P connector .
2 . Measur e th e resistanc e
betwee n th e No . 1 an d No . 2
terminals .
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(From pag e 19-66 ) AB S CONTRO L UNI T 22 P CONNECTO R
FLW (+ ) (GRN/BLU )
Chec k th e whee l senso r resis -
tance:1. Connec t th e whee l senso r 2 Pconnector .2. Measur e th e resistanc e
betwee n th e AB S contro l uni t
22 P connecto r positiv e sid e
an d negativ e sid e terminal s o f
th e appropriat e whee l sensor* .
I s th e resistanc e a s specified ?
— Front : 700 - 1,10 0— Rear : 1,400-2,00 0 Chec
k fo r a n ope n i n th e whee l
senso r circuit :1. Connec t th e AB S contro l uni t22P connecto r appropriat epositive sid e terminal * t o bod ygroun d wit h a jumpe r wire .2. Disconnec t th e appropriat ewheel sensor * 2 P connector .3. Chec k fo r continuit y betwee ntermina l No . 2 an d bod yground . Wir
e sid e o f femal e terminal s
NOTE : Chec k wit h th e AB S contro l uni t 22 P
connecto r disconnected .
FL W (+ ) (GRN/BLU )FR
W (+ ) (GRN/BLK )
WHEE L SENSO R 2 P CONNECTO R
Termina l sid e o f
mal e terminal s
I s ther e continuity ? Repai
r ope n in th e positiv e (+ ) cir -
cui t wir e betwee n th e AB S con -
tro l uni t an d appropriat e whee l
sensor .
Repair ope n in th e negativ e (- ) cir -
cui t wir e betwee n th e AB S con -
tro l uni t an d appropriat e whee l
sensor .
Correc t th e appropriat e whee lsensor ai r gap .
Measur e th e appropriat e whee l
senso r ai r ga p (se e pag e 19-103) .
Is th e ai r ga p OK ?
Chec k th e AB S functio n (se e pag e19-95 ).
JUMPE R WIR E JUMPE
R WIR E
Appropriat e Termina lPositive Sid e Negativ e Sid e4-1 (Right-front ) No . 5 : FR W (+ ) No . 4 : FR W (-)4- 2 (Left-front ) No . 3 : FL W (+ ) No . 2 : FL W (-)4- 4 (Right-rear ) No . 15 : RR W (+ ) No . 16 : RR W (-)4- 8 (Left-rear ) No.13 : RL W (+ ) No . 14 : RL W (-)
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Troubleshooting
DTC 5 , 5-4 , 5-8 : Rea r Whee l Loc k
The AB S contro l uni t monitor s th e rea r whee l senso r signal s durin g th e regula r diagnosi s (durin g driving) . Thi s diagnosi s
is no t performe d whe n th e parkin g brak e signa l i s ON . Th e AB S contro l uni t turn s th e AB S indicato r ligh t o n if i t detect s n o
signal(s ) fro m th e rea r whee l sensor(s ) du e to , fo r example , rea r whee l lock .
Possibl e causes :
Wheel spi n durin g cornerin g
Open circuit , interna l shor t o r shor t t o th e bod y groun d in th e whee l senso r syste m
Rear brak e dra g
Modulato r doe s no t decreas e pressur e properl y
Faulty AB S contro l uni t
— Whe n vehicl e i s driven , ABSindicato r ligh t i s ON .— Wit h th e SC S servic e connec -tor connecte d (se e pag e 19-40 ),DTC s 5 , 5- 4 and/o r 5- 8 ar e indi -
cated .
Chec k th e PAR K circuit :
1. Tur n th e ignitio n switc h O N (II) .2. Pres s th e parking brake pedal .
Doe s th e brak e syste m ligh t
com e on ? Parkin
g brak e switc h stuc k OFF .
Repai r ope n circui t betwee n th e
under-das h fuse/rela y bo x an d
parkin g brak e switch .
NOTE:The self-diagnosi s o f th e whee l senso r i s per -forme d i n thi s step .
Test-driv e wit h th e parkin g brak e released .
Does th e AB S indicato r ligh tcom e on ?
Chec k fo r rea r brak e drag :
1 . Rais e th e rea r o f th e vehicle ,
and suppor t i t wit h safet ystands (se e sectio n 1 ).2 . Spi n th e lef t and/o r righ t rea rwhee l an d chec k fo r brak e
drag . I
s cod e 4- 4 o r 4- 8 indicated ?
Perform th e troubleshootin g fo rthe rea r whee l sensor .
Perfor m th e appropriat e trouble -
shootin g fo r th e code .
Doe s th e brak e drag ?
Repair th e rea r brak e drag .
Check th e AB S functio n (se epage 19-95 ).
Th e probabl e caus e wa s tha t
tractio n wa s los t du e t o exces -
siv e cornerin g speed , etc .
Chec
k th e self-diagnosis :
Test-driv e th e vehicl e a t speed s
of 6 mp h (1 0 km/h ) o r more .
Confir m th e DT C (se e pag e 19-40 ).
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DTC 8-1 : AB S Functio n
The AB S contro l uni t monitor s th e AB S functionin g tim e durin g regula r diagnosis , an d it turn s th e AB S indicato r ligh t o n if
th e AB S is functionin g fo r a prolonge d time .
Possibl e causes :
Wheel senso r signa l disappear s a t speed s o f 6 mp h (1 0 km/h ) o r les s
Fault y AB S contro l uni t
— Wit h engin e running , AB S indi -
cato r ligh t i s ON .
— Wit h th e SC S servic e connec -
to r connecte d (se e pag e 19-40 ),
DT C 8- 1 is indicated .
Proble m verification :
Test-driv e th e vehicl e a t speed s
o f 1 2 mp h (2 0 km/h ) o r mor e fo r
mor e tha n 2 minutes .
Does th e AB S indicato r ligh tcom e on ? Th
e syste m is O K a t thi s time .
Chec k fo r loos e whee l senso r
connectors , an d chec k th e senso rinstallatio n (intermitten t trou -ble).Probabl e caus e wa s drivin g ove rroug h roads .
Is cod e 8- 1 indicated ? Perfor
m th e appropriat e trouble -
shootin g fo r th e code .
Replac e th e AB S contro l unit .
Confir
m th e DT C (se e pag e 19-40 ).
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ABS Functio n Tes t (cont'd )
Operatio n Sequenc e Simulate d b y Mode s o f AL B Checke r
NOTE : Th e whee l sensor s an d senso r wir e harnesse s ar e no t checke d b y th e AL B checker .
Mode 1 : Send s th e simulate d drivin g signa l 0 mp h ( 0 km/h ) 11 3 mp h (18 0 km/h ) 0 mph ( 0 km/h ) o f eac h whee l t o th e
AB S contro l uni t t o chec k th e syste m unde r th e norma l driving . Ther e shoul d b e n o kickback .
SIMULATE D DRIVIN G SIGNA L
Mode 2 : Send s th e drivin g signa l o f eac h wheel , the n send s th e loc k signa l o f th e left-rea r whee l t o th e AB S contro l uni t t o
chec k th e syste m unde r left-rea r whee l lock . Ther e shoul d b e kickback .
SIMULATE D DRIVIN G SIGNA L
Mode 3 : Send s th e drivin g signa l o f eac h wheel , the n send s th e loc k signa l o f th e right-rea r whee l t o th e AB S contro l uni t
t o chec k th e syste m unde r right-rea r whee l lock . Ther e shoul d b e kickback .
SIMULATE D DRIVIN G SIGNA L
Inspectio n Point s
I f th e AB S indicato r ligh t come s o n an d th e syste m stop s durin g th e inspection , confir m th e DT C an d perfor m th e appro -
priat e troubleshootin g fo r th e code .
I f ther e is n o kickbac k i n mode s 2 throug h 5 , an d th e AB S indicato r ligh t doe s no t com e on , th e followin g item s ar e proba -
bl e causes :
Pressur e switc h stuc k O N
Clogge d o r stuc k solenoi d outle t valv e
Modulato r wir e harnes s connector s improperl y connecte d
Mod
e 5 : Send s th e drivin g signa l o f eac h wheel , the n send s th e loc k signa l o f th e right-fron t whee l t o th e AB S contro l uni t
t o chec k th e syste m unde r right-fron t whee l lock . Ther e shoul d b e kickback .
SIMULATE D DRIVIN G SIGNA L
Mode 4 : Send s th e drivin g signa l o f eac h wheel , the n send s th e loc k signa l o f th e left-fron t whee l t o th e AB S contro l uni t
t o chec k th e syste m unde r left-fron t whee l lock . Ther e shoul d b e kickback .
SIMULATE D DRIVIN G SIGNA L
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Modulator Functio n Chec kRemova l
NOTE: Thi s inspectio n determine s whethe r th e basi c
brak e syste m continue s t o operat e normall y whe n th e
modulato r uni t high-pressur e sid e i s low .
1 . Reliev e syste m pressur e (se e pag e 19-97 ).
NOTE : Afte r relieving , tighte n th e bleede r t o 1 1 N- m
(1. 1 kgf-m , 8 Ibf-ft) .
BLEEDE R
2. Rais e th e vehicl e of f th e ground .
3. Hav e a n assistan t depres s th e brak e peda l firmly , an d
chec k tha t th e wheel s d o no t rotate . I f th e wheel s
rotate , replac e th e modulato r unit .
4 . Star t th e engin e t o operat e th e pum p motor , the n
ad d brak e flui d a s needed .
NOTE :
I f th e reservoi r empties , blee d th e high-pressur e
brak e fluid .
I f th e pum p moto r operate s fo r 4 0 second s o r
more , th e indicato r ligh t come s on , an d th e
pum p moto r stops . Sto p an d restar t th e engin e
t o operat e th e pum p moto r again .
I f th e AB S indicato r ligh t come s on , remov e th e
AB S B 2 (1 5 A ) fus e fo r 3 second s o r mor e t o
eras e th e DT C afte r servicing .
5 . Afte r th e pum p moto r stops , refil l th e reservoi r t o
th e MA X line .
6. Afte r servicing , mak e sur e th e AB S indicato r ligh t
goe s off . 1
. Disconnec t th e 14 P an d 2 P connectors .
2 . Disconnec t th e si x brak e lines , the n remov e th e
modulato r unit .
From
left-fron tFro
m
right-rea r
2 P CONNECTO R Fro
m
left-rea r
Fromright-fron t
RUBBERMOUNT
14P CONNECTO R
Frommaste r cylinde r
rea r sid e
BRACKE T
8 m m NU T21 N- m (2. 1 kgf- m
1 5 Ibf-ft )
Fro m
maste r cylinde r
fron t sid e
8 m m BOL T
2 2 N- m (2. 2 kgf-m , 1 6 Ibf-ft )
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Pulsers/Wheel Senso r
Inspectio n
Inspection points :
Resistanc e
Front: 700-1,10 0
Rear: 1,400-2,00 0
Ope n in th e wire s
Shor t t o bod y groun d i n th e wire s
Shor t th e wir e t o othe r on e
Installatio n
Chippe d pulse r
Air gap : 0.4 - 1. 0 m m (0.0 2 - 0.04 in)
Fron t
Rear
Remov e th e rea r brak e dis c t o inspec t th e rea r whee l
sensor ai r grip .
Whee l Senso r Replacemen t
NOTE:
B e carefu l whe n installin g th e sensor s t o avoi d twist -
in g th e wires .
Th e torqu e valu e o f th e bolt s i s a t 9. 8 N- m (1. 0 kgf-m ,
7 Ibf-ft) .
Front
FRON T WHEE L SENSO R
Rear
REA R WHEE L SENSO R
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