1996 ACURA RL KA9 wheel

Troubleshooting
ABS Dow n
Diagnosti c Troubl e Cod e (DTC ) 4-9 : AB S Dow n Diagnosi s
Th e TC S indicato r ligh t come s o n whe n th e vehicl e i s stopped , th e engin e i s running , an d th e signal s fro m al l fou r wheel s
ar e disconnecte d fo r mor e tha n 5 seconds .
NOTE : Whe n th e TC S indicato r ligh t doe s no t com e o n bu t DT C 4- 9 i s memorized , th e caus e ma y b e tha t th e vehicl e wa s
drive n wit h th e AB S B 2 (1 5 A ) fus e remove d o r th e DT C wa s no t erase d afte r troubleshootin g th e ABS . Test-driv e th e vehi -
cle again , and chec k whethe r the indicato r light come s on. I f th e indicato r light doe s not com e on, th e syste m is OK . Eras e
the DTC .
Does th e AB S indicato r ligh t
com e on ? Perfor
m th e AB S troubleshooting .
Chec k fo r loos e AB S contro l uni t
connectors . I f the y ar e O K an d
th e proble m recurs , replac e th e
TC S contro l unit .
Chec
k fo r AB S indicato r light :
Star t th e engine .
Wit
h engin e runnin g o r driv -
ing , TC S indicato r ligh t i s ON .
Wit h th e SC S servic e connec -
to r connecte d (se e pag e
19-159 ), DT C 4- 9 is indicated .
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Component Locations

SERVICE CHECK CONNECTOR (2P)

RIGHT-REAR WHEEL SENSOR

VSA CONVERTER UNIT

VSA MODULATOR

CONTROL UNIT

TCS CONTROL

VALVE SENSOR

RIGHT-FRONT

WHEEL SENSOR
PRECHARGE

PUMP MOTOR
STEERING

ANGLE SENSOR

YAW RATE/LATERAL

ACCELERATION SENSOR

TCS CONTROL VALVE

ACTUATOR

UNDER-HOOD

RELAY BOX C
UNDER-HOOD

FUSE/RELAY BOX
VSA OFF SWITCH

UNDER-DASH FUSE/RELAY BOX

LEFT-FRONT WHEEL SENSOR
LEFT-REAR

WHEEL SENSOR

GAUGE ASSEMBLY

ABS INDICATOR

VSA SYSTEM INDICATOR
UNDER-HOOD FUSE/RELAY BOX

STOP/HORN

(20 A) FUSE

BRAKE SYSTEM INDICATOR

VSA ACTIVATION INDICATOR

UNDER-DASH FUSE/RELAY BOX
TCS

(15 A) FUSE

VSA

(20 A) FUSE

METER

(15 A) FUSE

ECU

(20 A) FUSE

METER

(7.5 A) FUSE
BATTERY

(120 A) FUSE

VSA MOTOR (40 A) FUSE

IG SW (50 A) FUSE

UNDER-HOOD RELAY BOX C

FAIL-SAFE RELAY

GAUGE RELAY
PCM

R/C MIRROR

(7.5 A) FUSEProCarManuals.com

Troubleshooting Precaution s
System Indicator s
If th e syste m is OK , th e AB S indicato r goe s of f onc e afte r turnin g th e ignitio n switc h O N (II ) withou t startin g th e engine ,
an d the n com e o n agai n an d g o of f severa l second s late r afte r startin g th e engine . Thi s occur s becaus e th e VS A contro l
uni t i s turne d o n b y th e IG 2 powe r source .
Th e AB S indicato r o r VS A syste m indicato r come s o n whe n th e VS A contro l uni t detect s a proble m in th e system .
Th e AB S indicato r o r VS A syste m indicato r wil l als o com e o n unde r thes e conditions , eve n thoug h th e syste m is oper -
atin g properly :
— Th e vehicl e goe s int o a spi n
— Th e AB S continue s t o operat e fo r a lon g tim e
— Th e vehicl e is subjecte d to a n electrica l signa l disturbanc e
I f ther e is a faul t i n th e PGM-F I system , onl y th e VS A syste m indicato r come s on .
Th e VS A Activatio n Indicato r wil l flas h whe n onl y th e driv e wheel s rotat e o r on e o f th e driv e wheel s is stuck . Whe n thi s
occurs , th e AB S indicato r an d VS A syste m indicato r d o no t com e on .
T o determin e th e actua l caus e o f th e problem , questio n th e custome r abou t th e problem , takin g thes e condition s int o con -
sideration .
Whe n a proble m is detecte d an d th e AB S o r VS A indicato r come s on , ther e ar e case s whe n th e indicato r stay s o n unti l
th e ignitio n switc h i s turne d OFF , an d case s whe n th e indicato r goe s of f automaticall y whe n th e syste m return s t o nor -
mal . Fo r DT C 6 1 an d 62 , th e indicato r goe s of f automaticall y whe n th e syste m return s t o normal . Fo r al l othe r codes ,
th e indicato r stay s o n unti l th e ignitio n switc h is turne d OFF .
Fo r DTC s 12 , 14 , 16 , 18 , 51 , 52 , 53 , 66 , 6 8 an d 84 , th e AB S indicato r goe s of f whe n th e vehicl e is drive n agai n an d th e
syste m is O K afte r th e ignitio n switc h is turne d fro m OF F to O N (II) . However , i f th e DT C is cleared , th e CP U reset s an d
th e indicato r goe s of f righ t afte r th e engin e is starte d if th e syste m is OK .
Th e AB S is no t operationa l whe n th e AB S indicato r i s ON ; th e VS A is no t operationa l whe n th e VS A indicato r i s ON .
Whe n th e VS A indicato r an d MI L ar e bot h ON , troubleshoo t th e PGM-F I syste m first .
Diagnosti c Troubl e Cod e (DTC )
Th e memor y ca n hol d an y numbe r o f DTCs . However , whe n th e sam e DT C is detecte d mor e tha n once , th e mor e recen t
DT C is writte n ove r th e earlie r one . Therefore , whe n th e sam e proble m is detecte d repeatedly , i t i s memorize d a s a sin -
gle DTC .
The DTC s ar e indicate d in ascendin g numbe r order , no t i n th e orde r the y occur .
Th e DTC s ar e memorize d in th e EEPRO M (non-volatil e memory) . Therefore , th e memorize d DTC s canno t b e cancele d
b y disconnectin g th e battery . Perfor m th e specifie d procedure s to clea r th e DTCs .
Self-diagnosi s
Self-diagnosis can be classifie d int o tw o categories :
— Initia l diagnosis : Performe d righ t afte r th e engin e start s an d unti l th e AB S o r VS A indicato r goe s off .
— Regula r diagnosis : Performe d righ t afte r th e initia l diagnosi s unti l th e ignitio n switc h is turne d OFF .
When a proble m is detecte d b y self-diagnosis , th e VS A contro l uni t shift s to fail-saf e mode .
Kickbac k
The pum p moto r operate s whe n th e AB S is functioning , an d th e flui d in th e reservoi r i s force d ou t t o th e maste r cylinder ,
causing kickbac k a t th e brak e pedal .
Pum p Moto r
Th e pum p moto r operate s whe n th e AB S is functioning .
The VS A contro l uni t check s th e pum p moto r operatio n durin g initia l diagnosi s whe n th e vehicl e is started .
You ma y hea r th e moto r operat e a t thi s time , bu t i t i s normal .
Brak e Flui d Replacement/Ai r Bleedin g
Brak e flui d replacemen t an d ai r bleedin g procedure s ar e identica l t o th e procedure s us e o n vehicle s no t equippe d wit h
VSA . T o eas e bleeding , star t wit h th e fron t wheels .
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DTC 11, 13, 15, 17: Wheel Sensor (Open/Short to Body Ground/Short to Power)

Check for a short to power in the

wheel sensor circuit:

1. Disconnect the VSA control

unit 42P connector.

2. Start the engine.

3. Measure the voltage between

the VSA control unit 42P con-

nector appropriate wheel sen-

sor (+) circuit terminal and

body ground (see table).
DTC

11 (Right-front)

13 (Left-front)

15 (Right-rear)

17 (Left-rear)
Appropriate Terminal

(+) Side

No. 16:FRS(+)

No. 28:FLS(+)

No. 31: RRS (+)

No.14: RLS(+)
(-) Side

No. 15: FRS(-)

No. 13:FLS (-)

No. 30:
RRS
(-)

No. 29: RLS (-)
VSA CONTROL UNIT 42P CONNECTOR

Is there battery voltage?
Repair short to power in the {+)

or (-) circuit wire between the

VSA control unit and appropriate

wheel sensor.
Wire side of female terminals

Check for a short to body ground

in the wheel sensor circuit:

1. Turn the ignition switch OFF.

2. Check for continuity between

the VSA control unit 42P con-

nector appropriate wheel sen-

sor (+) circuit terminal and

body ground (see table).

Is there continuity?
Repair short to body ground in

the (+) or (-) circuit wire between

the VSA control unit and the

appropriate wheel sensor.

Replace the appropriate wheel

sensor.

Check for an open in the wheel

sensor circuit:

Measure the resistance between

the VSA control unit 42P connector

appropriate wheel sensor (+) and

(-) circuit terminals (see table).

Is the resistance between

450 - 2,000 at 68°F?
• Repair open in the (+) or (-) cir-

cuit wire between the VSA con-

trol unit and the appropriate

wheel sensor.

• Replace the appropriate wheel

sensor.

Check for loose terminals in the

VSA control unit 42P connector.

If necessary, substitute a known-

good VSA modulator-control

unit, and recheck.ProCarManuals.com

Troubleshooting
DTC 12 , 14 , 16 , 18 : Whee l Senso r (Electrica l Noise/Intermitten t Interruption )
NOTE: If the ABS indicator comes on for the reasons described below, the indicator should go off when you test drive the
vehicle a t speed s abov e 1 9 mp h (3 0 km/h) .
Onl y th e driv e wheel s rotate d
Th e vehicl e spu n
Electrica l nois e
Is ther e continuity ?
DTC
12
1 4
16
18
Appropriat e Whee l Senso r
Right-fron t
Left-fron t
Right-rea r
Left-rear
Reinstal l o r replac e th e appropri -
at e whee l senso r o r pulser . VS
A CONTRO L UNI T 42 P CONNECTO R
DTC
12 (Right-front )
1 4 (Left-front )
16 (Right-rear )
18 (Left-rear )
Appropriat e Termina l
(+ ) Sid e
No. 16:FRS(+ )
No. 28:FLS(+ )
No. 31:RRS(+ )
No. 14:RLS(+ )
(-) Sid e
No. 15:FRS( - )
No . 13 : FL S (- )
No . 30 : RR S (- )
No . 29 : RL S (- )
Wir e sid e o f femal e terminal s
Repair shor t t o wir e betwee n th eappropriat e whee l senso r (+ ) an d
(- ) circuits .
DTC
12 (Right-front )
1 4 (Left-front )
16 (Right-rear )
18 (Left-rear )
Appropriat e
Termina l
No. 16:FRS(+ )
No. 28:FLS(+ )
No.31:RRS(+ )
No. 14:RLS(+ )
Other Termina l
No. 28 : FL S (+)
No . 16:FRS(+ )
No. 16 : FR S (+ )
No . 16 : FR S (+ )
No . 31:RRS(+ )
No . 31:RRS(+ )
No. 28 : FL S (+ )
No . 28 : FL S (+ )
No . 14:RLS(+ )
No. 14:RLS(+ )
No. 14 : RL S (+ )
No . 31 : RR S (+ )
Repai r shor t t o wir e betwee n th e
appropriat e whee l senso r an d
th e othe r whee l sensor .
Clear th e DTC , an d test-driv e th evehicle . I f th e AB S indicato rcomes o n an d th e sam e DT C i sindicated , replac e th e VS A mod -ulator-contro l unit .
Chec k fo r a shor t t o anothe r wir ein th e whee l senso r circuit :Check fo r continuit y betwee n th eappropriat e whee l senso r (+ ) circui ttermina l an d othe r whee l senso r(+) circui t terminal s (se e table) .
Is ther e les s tha n 45 0 ?
Visuall y chec k fo r appropriat ewheel senso r an d pulse r installa -tion (se e table) .
Are the y installe d correctly ?
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DTC 25 : Ya w Rat e Senso r
Do thes e component s mee t
th e norma l standards ?
Check fo r a shor t t o powe r i n th eYR S RE F circuit :
1 . Disconnec t th e VS A contro l
uni t 42 P connector , th e ya w
rate/latera l acceleratio n sen -
so r 6 P connector .
2 . Tur n th e ignitio n switc h O N (II) .
3 . Measur e th e voltag e betwee n
th e VS A contro l uni t 42 P con -
necto r termina l No . 1 0 an d
bod y ground .
I s ther e batter y voltage ?
Chec k fo r a shor t t o powe r i n th e
YRS T circuit :Measur e th e voltag e betwee n th e
VS A contro l uni t 42 P connecto r
termina l No . 9 an d bod y ground .
I s ther e batter y voltage ?
Chec k fo r a shor t t o powe r i n th e
YRS S circuit :Measur e th e voltag e betwee n th e
VS A contro l uni t 42 P connecto r
termina l No . 4 1 an d bod y ground .
I s ther e batter y voltage ?
(To pag e 19-224 )
Repair t o norma l standards .
VSA CONTRO L UNI T 42 P CONNECTO R
Wir e sid e o f femal e terminal s
Repai r shor t t o powe r i n th e wir e
betwee n th e ya w rate/latera l
acceleration senso r an d th e VS Acontro l unit .
Repai r shor t t o powe r i n th e wir e
betwee n th e ya w rate/latera l
acceleratio n senso r an d th e VS A
contro l unit .
Repai r shor t t o powe r i n th e wir e
betwee n th e ya w rate/latera l
acceleration senso r an d th e VS Acontro l unit .
Chec
k th e wheels , tires , suspen -
sion , an d alignment .
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Troubleshooting
DTC 26 : Latera l Acceleratio n Senso r
Check th e wheels , tires , suspen -sion, an d alignment .
Do thes e component s mee t
th e norma l standards ?
Chec k fo r installatio n directio n o f
th e ya w rate/latera l acceleratio n
sensor.The senso r connecto r sid e mus t
b e facin g backward .
Is i t correct ?
Check fo r a shor t t o powe r i n th eAY circuit :1. Disconnec t th e VS A contro lunit 42 P connector , th e ya wrate/latera l acceleratio n sen -
so r 6 P connector .
2 . Tur n th e ignitio n switc h O N (II) .
3 . Measur e th e voltag e betwee n
th e VS A contro l uni t 42 P con -
necto r termina l No . 8 an d bod y
ground .
Is ther e batter y voltage ?
Chec k fo r a shor t t o bod y groun d
i n th e A Y circuit :
1. Tur n th e ignitio n switc h OFF .2. Chec k fo r continuit y betwee n
th e VS A contro l uni t 42 P con -
necto r termina l No . 8 an d bod y
ground .
I s ther e continuity ?
(To pag e 19-227 )
Repair t o norma l standards .
Reinstall th e ya w rate/latera lacceleration senso r correctly .
VSA CONTRO L UNI T 42 P CONNECTO R
Wir e sid e o f femal e terminal s
Repai r shor t t o powe r i n th e wir e
betwee n th e ya w rate/latera l
acceleration senso r an d th e VS Acontro l unit .
Repai r shor t t o bod y groun d in th ewir e betwee n th e ya w rate /lateral acceleratio n senso r a n d th e
VS A contro l unit .
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Troubleshooting

DTC 71: Abnormal Wheel Speed Signal

Are any DTCs except 71 indicated?

Check the tires.

Are tires with specified size and

inflated to specification?

Check for brake drag.

Do the brakes drag?

Visually check for appropriate

wheel sensor and pulser installa-

tion (see table).

Are they installed correctly?

Check the four pulser gears for a

chipped tooth (see table).

Is the pulser OK?

Problem Verification:

1. Clear the DTC.

2. Test-drive the vehicle at 19

mph (30 km/h) or more.

3. Verify the DTC.

Is DTC 71 indicated?

YES

Check for loose terminals in the

VSA control unit 42P connector.

If necessary, substitute a known-

good VSA modulator-control

unit, and recheck.
Preform the appropriate trou-

bleshooting for the DTC.

Replace the tire(s) with the spec-

ified size.

Repair the brake drag.

Reinstall or replace the wheel

sensor or pulser.

Replace the driveshaft or hub

unit. (Chipped pulser gear.)

The system is OK at this time.
Verify the DTC.ProCarManuals.com