1996 ACURA RL KA9 ECU

Troubleshooting
Barometric Pressur e (BARO ) Signa l
Diagnosti c Troubl e Cod e (DTC ) 3-5 : Barometri c Pressur e (BARO ) Signa l Diagnosi s
With engin e running , TC S indi -cato r ligh t i s ON .MIL is OFF .With th e SC S servic e connec -
to r connecte d (se e pag e
19-159 ), DT C 3- 5 is indicated .
Chec k fo r a shor t t o bod y groun d
i n th e BAR O circuit :
1 . Disconnec t th e PC M connecto r
D (22P ) an d TC S contro l uni t20P connectors .2. Chec k fo r continuit y betwee n
th e PC M connecto r D (22P ) ter -
mina l No . 3 an d bod y ground .
I s ther e continuity ?
Chec k th e BAR O circui t insid e
the PCM :1. Connec t th e PC M connecto rD (22P) .2. Tur n th e ignitio n switc h O N (II) .3. Measur e th e voltag e betwee n
th e PC M connecto r D (22P ) ter -
mina l No . 3 an d bod y ground .
I s ther e abou t 3 V ?
Chec k fo r a n ope n i n th e BAR Ocircuit :Measur e th e voltag e betwee n th eTC S contro l uni t 20 P connecto rterminal No . 1 3 an d bod y ground .
I s ther e abou t 3 V ?
Th e syste m is O K at thi s time .If th e proble m recurs , replac e
th e TC S contro l unit . NOTE
: Whe n bot h th e TC S indicato r
light an d th e MI L ar e ON , troubleshoo tthe PGM-F I syste m first .
PCM CONNECTO R D (22P )
Wir e sid e o f femal e terminal s
Repai r shor t t o bod y groun d in
th e wir e betwee n th e PC M an d
TC S contro l unit .
Chec k fo r loos e PC M connectors .If necessary , substitut e a known -good PC M an d recheck .
TCS CONTRO L UNI T 20 P CONNECTO R
Repai r ope n in th e wir e betwee n
th e PC M an d TC S contro l unit . Wir
e sid e o f femal e terminal s
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Throttle Positio n Senso r (TPS ) Signa l
Diagnosti c Troubl e Cod e (DTC ) 3-6 : Throttl e Positio n Senso r (TPS ) Signa l Diagnosi s
With engin e running , TC S
indicato r ligh t i s ON .
MIL is OFF .With th e SC S servic e connec -
to r connecte d (se e pag e
19-159 ), DT C 3- 6 is indicated .NOTE
: Whe n bot h th e TC S indicato rlight an d th e MI L ar e ON , trouble -shoot th e PGM-F I syste m first .
TCS CONTRO L UNI T 14 P CONNECTO R
Check fo r a n ope n i n th e TP S cir -cuit :Measur e th e voltag e betwee n th e
TC S contro l uni t 14 P connecto r
termina l No . 1 4 an d bod y ground .
I s th e voltag e a s specified ?
Full y closed : abou t 0. 5 V
Full y open : abou t 4. 5 V Repai
r ope n in th e wir e betwee n
th e PC M an d TC S contro l unit . Wir
e sid e o f femal e terminal s
Th e syste m is O K at thi s time .
I f th e proble m recurs , replac e
th e TC S contro l unit .
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From pag e 19-18 0
Check th e TC S contro l valv e sen -sor:1. Remov e th e intak e ai r duc t(see pag e 19-192 ).2 . Tur n th e ignitio n switc h O N (II) .
3 . Connec t th e batter y an d TC S
contro l valv e actuato r (se e
pag e 19-189 ).
4 . Measur e th e voltag e betwee n
th e TC S control unit H P con -
necto r termina l No . 6 an d
bod y ground . TC
S CONTRO L UNI T 14 P CONNECTO R
Wir e sid e o f femal e terminal s
I s th e voltag e a s specified ?
Full y closed : abou t 0. 5 V
Full y open : abou t 4. 5 V
NOTE : Ther e shoul d b e a smoot h
transitio n fro m abou t 4. 5 V an d
0. 5 V as th e TC S contro l valv e is
closed .
Check fo r a n ope n i n th e wir e
betwee n th e TC S contro l uni t
and TC S contro l valv e sensor .If th e wir e is OK , replac e th e TC S
contro l valv e assembl y (fault y
TC S contro l valv e sensor ) an d
recheck .
The syste m is O K at thi s time .
I f th e proble m recurs , replac e
th e TC S contro l unit .
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From pag e 19-18 2
Chec k fo r a n ope n i n th e FRP ,
FLP , RR P and/o r RL P circuit :
Measur e th e voltag e betwee n th e
AB S contro l uni t 26 P o r 22 P con -
necto r appropriat e terminal * an d
bod y ground .
I s ther e abou t 5 V ?
Chec k th e AB S contro l unit :
1. Tur n th e ignitio n switc h OFF .2. Connec t th e AB S contro l uni t
26 P o r 22 P connector .
3 . Rais e th e vehicle , an d suppor t
i t wit h safet y stands .
4 . Tur n th e ignitio n switc h O N (II) .
5 . Rotat e th e appropriat e wheel* ,
an d measur e th e voltag e
betwee n th e AB S contro l uni t
26 P o r 22 P connecto r appro -
priat e terminal * an d bod y
ground .
I s ther e abou t 2. 5 V ? *
'9 6 - 9 7 model s
DTC
4-1 (Right-front )
4- 2 (Left-front )
4-4 (Right-rear )
4-8 (Left-rear )
Appropriat e Termina l
No. 6 : FR P
No. 4 : FL P
No. 20 : RR P
No. 18 : RL P
* '9 8 - 9 9 model s
DTC
4-1 (Right-front )
4- 2 (Left-front )
4-4 (Right-rear )
4-8 (Left-rear )
Appropriat e Termina l
No. 5 : FR P
No. 3 : FL P
No. 15 : RR P
No. 13 : RL P
Repai r ope n in th e wir e betwee n
th e AB S contro l uni t an d TC S con -
tro l unit . '9
6 - 9 7 model s
AB S CONTRO L UNI T 26 P CONNECTO R
'9 8 - 9 9 model s
AB S CONTRO L UNI T 22 P CONNECTO R
Wir e sid e o f femal e terminal s
Chec k fo r loos e AB S contro l uni t
connectors . I f necessary , substi -
tut e a known-goo d AB S contro l
uni t an d recheck .
Th e syste m is O K a t thi s time .
I f th e proble m recurs , replac e
th e TC S contro l unit .
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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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Fail-safe Rela y
Diagnosti c Troubl e Cod e (DTC ) 5-1 : Fail-saf e Rela y Diagnosi s
With engin e running , TC S
indicato r ligh t i s ON .
With th e SC S servic e connec -
to r connecte d (se e pag e
19-159 ), DT C 5- 1 is indicated .
Remov e th e fail-saf e relay , an d
chec k it (se e sectio n 23 ).
I s th e rela y OK ?
Chec k fo r a shor t t o bod y groun d
i n th e FS R circuit :
1 . Disconnec t th e fail-saf e rela y
and TC S control unit 20 P con -nectors .
2 . Chec k fo r continuit y betwee n
the TC S contro l uni t 20 P con -necto r termina l No . 6 an d bod yground .
Is ther e continuity ?
Chec k th e FS R circui t insid e th e
TC S contro l unit :
1 . Connec t th e fail-saf e rela y an d
TC S contro l uni t 20 P connec -
tors .
2. Tur n th e ignitio n switc h O N (II) .3. Measur e th e voltag e betwee nthe TC S contro l uni t 20 P con -necto r termina l No . 6 an d bod yground .
Is ther e batter y voltage ?
Chec k fo r a shor t t o powe r i n th e
VP M circuit :
Measur e th e voltag e betwee n th e
TC S contro l uni t 20 P connecto rterminal No . 1 0 an d bod y ground .
Is ther e batter y voltage ?
Th e syste m is O K a t thi s time .
I f th e proble m recurs , replac e
th e TC S contro l unit . Replac
e th e fail-saf e relay .
TCS CONTRO L UNI T 20 P CONNECTO R
Wir e sid e o f femal e terminal s
Repai r shor t t o bod y groun d i n
th e wir e betwee n th e fail-saf e
rela y an d TC S contro l unit .
Replac e th e TC S contro l unit .
(Shor t circui t insid e th e unit )
Repai r shor t t o powe r i n th e wir ebetwee n th e TC S contro l uni tand fail-saf e relay .
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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

DTC 58: Engine Speed Signal

Check for a short to body ground

in the NEP circuit:

1. Disconnect the VSA converter

unit 26P connector, the PCM

connector C (12P) and the

gauge assembly 22P connec-

tor.

2. Check for continuity between

the PCM connector C (12P)

terminal No. 8 and body

ground.

Is there continuity?

Check the PCM:

1. Connect the PCM connector C

(12P).

2. Start the engine.

3. Measure the voltage between

the PCM connector C (12P) ter-

minal No. 8 and body ground.

Is there about 6V?

Check for an open in the NEP cir-

cuit:

Measure the voltage between the

VSA converter unit 26P connec-

tor terminal No. 21 and body

ground.

Is there about 6 V?

The system is OK at this time.

If the problem recurs, replace

the VSA converter unit.
PCM CONNECTOR C (12P)

Wire side of female terminals

Repair short to body ground in

the wire between the VSA con-

verter unit, PCM and the gauge

assembly.

NOTE:

Use the 10 V range or a similar range in

an analog tester.

Check with the engine idling and

warmed-up.

Check for loose terminals in the

PCM connectors. If necessary,

substitute a known-good PCM,

and recheck.

NOTE:

Use the 10 V range or a similar range in

an analog tester.

Check with the engine idling and

warmed-up.

VSA CONVERTER UNIT 26P CONNECTOR

Repair open in the wire between

the PCM and the VSA converter

unit.

Wire side of female terminalsProCarManuals.com