sensor ACURA RL KA9 1996 Service Repair Manual

Component Locations

ABS CONTROL UNIT

MODULATOR UNIT
SERVICE CHECK CONNECTOR (2P)

ABS INSPECTION CONNECTOR (6P)

RIGHT-REAR WHEEL SENSOR

RIGHT-FRONT WHEEL

SENSOR CONNECTOR

RIGHT-FRONT

WHEEL SENSOR
LEFT-REAR WHEEL

SENSOR CONNECTOR

LEFT-REAR

WHEEL SENSOR

RIGHT-REAR WHEEL

SENSOR CONNECTOR

UNDER-HOOD

RELAY BOX B

UNDER-HOOD

FUSE/RELAY BOX
UNDER-DASH FUSE/RELAY BOX

LEFT-FRONT WHEEL SENSOR

LEFT-FRONT WHEEL

SENSOR CONNECTOR

GAUGE ASSEMBLY:

ABS INDICATOR LIGHT

UNDER-DASH FUSE/RELAY BOX:

METER

(7.5 A) FUSE
ABS B2

(15 A) FUSE

ABS B1

(20 A) FUSE

METER

(15 A) FUSE
BATTERY

(120 A) FUSE

ABS MOTOR (40 A) FUSE

IG SW (50 A) FUSE

UNDER-HOOD RELAY BOX C:

REAR FAIL-SAFE RELAY

METER RELAY

FRONT FAIL-SAFE RELAY
ABS
UNIT

(7.5 A) FUSE
STOP/HORN

(ISA) FUSE
ABS PUMP

MOTOR RELAY
UNDER-HOOD FUSE/RELAY BOX:

ECU

(20 A) FUSE

R/C MIRROR

(7.5 A) FUSEProCarManuals.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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Troubleshooting
DTC 4- 1 (Right-front) , 4- 2 (Left-front) , 4- 4 (Right-rear) , 4- 8 (Left-rear) :
Whee l Senso r (cont'd )
(From pag e 19-65 )
ABS CONTRO L UNI T 22 P CONNECTO R
Chec k fo r a shor t t o bod y groun d
i n th e whee l senso r positiv e (+ )
circuit :
1 . Disconnec t th e AB S contro l
uni t 22 P connector .
2 . Chec k fo r continuit y betwee n
th e appropriat e whee l senso r
positive (+ ) circui t terminal *and bod y ground . NOTE
: Chec k wit h th e appropriat e whee l
senso r 2 P connecto r disconnected .
DTC4-1 (Right-front )4-2 (Left-front )4-4 (Right-rear )4-8 (Left-rear )
Appropriat e Termina lNo. 5 : FR W (+ )No . 3 : FL W (+ )No . 15 : RRW(+ )No. 13 : RL W (+ )
Is ther e continuity ? Repai
r shor t t o bod y groun d in th e
positiv e (+ ) circui t wir e betwee n
th e AB S contro l uni t an d appropri -
at e whee l sensor . Wir
e sid e o f femal e terminal s
Chec k fo r a shor t t o bod y groun d
i n th e whee l senso r negativ e (- )
circuit :
Chec k fo r continuit y betwee n th e
appropriat e whee l senso r nega -
tiv e (- ) circui t terminal * an d bod y
ground .
DTC4-1 (Right-front )4-2 (Left-front )4-4 (Right-rear )4-8 (Left-rear )
Appropriat e Termina lNo. 4 : FR W (-)No . 2 : FL W (-)No . 16 : RR W (-)No . 14 : RL W (-)
Is ther e continuity ? Repai
r shor t t o bod y groun d in th e
negativ e (- ) circui t wir e betwee n
th e AB S contro l uni t an d appropri -
at e whee l sensor .
(T o pag e 19-67 )
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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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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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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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Component Locations

SERVICE CHECK CONNECTOR (2P)

RIGHT-REAR WHEEL SENSOR

ABS CONTROL UNIT

MODULATOR UNIT

LEFT-REAR

WHEEL SENSOR

RIGHT-FRONT

WHEEL SENSOR

UNDER-HOOD RELAY BOX C
UNDER-DASH FUSE/RELAY BOX

LEFT-FRONT WHEEL SENSOR

GAUGE ASSEMBLY
UNDER-HOOD FUSE/RELAY BOX

ABS INDICATOR

UNDER-DASH FUSE/RELAY BOX

R/C MIRROR

(7.5 A) FUSE

METER

(7.5 A) FUSE
STOP/HORN

(15 A) FUSE

ABS
UNIT

(7.5 A) FUSE

ABS

(20 A) FUSE
ABS PUMP

MOTOR RELAY

METER

(15 A) FUSE
BATTERY

(120 A) FUSE

ABS MOTOR

(40 A) FUSE

IG SW (50 A) FUSE

UNDER-HOOD RELAY BOX C

GAUGE RELAY

FAIL-SAFE RELAY
UNDER-HOOD FUSE/RELAY BOXProCarManuals.com

Anti-lock Brake System (ABS)

Features/Construction (cont'd)

ABS 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 has 3-modes: pressure reduction, pressure retaining, and pressure intensifying.

ABS CONTROL UNITProCarManuals.com

Self-diagnosis

1. The ABS control unit is equipped with a main CPU and a sub CPU, that check each other for problems.

2. The CPUs check the circuit of the system.

3. Self-diagnosis can be classified into 2 categories.

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

Regular diagnosis: Performed right after the initial diagnosis until the ignition switch is turned OFF.

4. When a problem is detected by self-diagnosis, the system:

Turns the fail-safe relay OFF

Turns the solenoid valve OFF

Turns the pump motor OFF

Turns the ABS indicator ON

Self-diagnosis Table

Diagnostic Trouble

Code(DTC)

11, 13, 15, 17

12,14,16,18

21-24

31-38

41-44

51

52

53

54

61

62

71

81
Detection Item

Wheel sensor (open/short to body ground/short to power)

Wheel sensor (electrical noise/intermittent Interruption)

Pulser

Solenoid (short to body ground/short to wire)

Wheel lock

Motor lock

Motor stuck OFF

Motor stuck ON

Fall-safe relay

Low ignition voltage

High ignition voltage

Different diameter tire

Central Processing Unit (CPU) diagnosis, and ROM/RAM diagnosis
Detection

Timing
Initial
Diagnosis

O

O

O

O
Regular
Diagnosis
O

O

O

O

O

O

O

O

O

O

O

O
Fail-safe Mode

A

S, A and L, S and L

A and L

S

A and L

S and L

A and L

A and L

S

B

B

S

S

Operation Mode Table

Operation

Mode

Regular

operation

Fail-safe

mode-S

Fail-safe

mode-A

Fail-safe

mode-L

Fail-safe

mode-B
Description

Operation in normal condition

The ABS control unit turns the system off when the control unit detects a problem.

If the ABS control unit detects a malfunction during an emergency stop, it will turn off the malfunc-

tioning component, and continue to modulate the rest of the ABS system until the vehicle comes to

a stop. At that, the entire system will be turned off until the problem goes away.

The ABS control unit stores a DTC in back-up memory when it detects a problem. If a problem is

detected when the ignition switch is turned ON (II), the ABS control unit will turn the system off. If

the problem goes away, the ABS control unit will turn the system on again.

The ABS control unit will turn the system off if ignition voltage drops, and will turn on again when

ignition voltage returns to normal.
ABS
Indicator

OFF

Comes ON when a

problem is detected.

Comes ON when a

problem is detected.

ON

Comes ON when a

problem is detected.

On-board Diagnosis Function

The ABS control unit is connected to the 16P Data Link Connector.

The ABS can be diagnosed with the Honda PGM Tester.

The ALB Checker cannot be used with this system. For air bleeding, and checking wheel sensor signals, use the Honda

PGM Tester. See the Honda PGM Tester user's manuals for specific operating instructions.
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