ACURA TL 1995 Service Repair Manual

System Descriptio n
Fail-Safe Functio n
I f th e contro l uni t detect s a n abnormality , i t shut s th e
tractio n contro l syste m of f an d cause s th e TC S indicato r
ligh t t o com e on . Howeve r i f th e abnormalit y i s detecte d
whil e th e TC S is activated , th e contro l uni t firs t estab -
lishe s th e appropriat e whee l spi n velocity , the n shut s
th e syste m down , thu s preventin g excessiv e whee l spin .
Self-Diagnosi s Functio n
I f th e contro l uni t detect s a n abnormality , i t record s a
Diagnosti c Troubl e Cod e (DTC ) whic h ca n b e use d t o
diagnos e th e problem . Th e DT C is show n a t th e TC S
indicato r ligh t whe n th e Servic e Chec k connecto r termi -
nal s ar e connecte d wit h th e SC S servic e connector .
Steerin g Angl e Detectio n
Steerin g angl e i s detecte d b y th e steerin g angl e sensor .
Th e dis c wit h th e slit s o f th e regula r patter n i s provide d
betwee n th e facin g part s o f th e ligh t emittin g par t (LED) ,
an d th e ligh t receivin g par t (phot o transistor) . A s th e dis c
rotates , i t passe s an d shut s of f th e ligh t fro m th e LED .
The ligh t whic h passe d throug h a sli t i s converte d int o
th e electri c curren t b y th e phot o transistor , an d th e wave -
for m o f thi s electri c curren t i s shape d b y th e comparato r
t o outpu t th e dis c rotatio n a s th e rectangula r signal .
Th e analysi s performanc e o f th e syste m is improve d b y
providin g th e fixe d sli t i n fron t o f th e LED , an d thereb y
identifyin g th e brightnes s an d darknes s o f th e ligh t whic h
i s receive d a t th e phot o transisto r clear .
Th e outpu t signa l i s th e 2-phas e outpu t (A-phas e an d B -
phase) , an d th e steerin g whee l turnin g angl e an d th e
turnin g directio n ar e calculate d b y th e TC S contro l unit .
Vehicl e Spee d Detectio n
Whee l rotatio n spee d i s detecte d b y th e whee l sensors ,
locate d a t eac h wheel . Th e signal s ar e sen t t o th e con -
tro l unit , whic h compare s eac h wheel' s spee d an d deter -
mine s whethe r tractio n contro l i s required .
TCS INDICATO R LIGH T
FIXE D SLI T LIGH
T RECEIVIN G PAR T
(PHOT O TRANSISTOR )
LIGH T EMITTIN G PAR T (LED )
SLIT
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Engine Outpu t Contro l
Whe n th e TC S is activated , th e TC S contro l uni t signal s th e TC S contro l valv e actuato r an d PCM . Th e actuato r i s linke d to
th e TC S contro l valv e whic h is normall y returne d to full y ope n positio n b y th e tw o retur n springs .
Althoug h th e throttl e valv e is stil l withi n th e driver' s control , th e engin e outpu t i s relaxe d b y th e TC S contro l valv e an d
PC M to achiev e optimu m traction .
TCS CONTRO L VALV E SENSO R
TCS CONTRO L VALV E
TCS CONTRO L VALV ERETUR N SPRING S
TCS CONTRO L VALV EACTUATO R (D C MOTOR )
DURING NORMA L DRIVING : DURING TC S ACTUATION :
TC S CONTRO L VALV E
TC S CONTRO L VALV E
ACTUATO R (D C MOTOR ) TC
S CONTRO L VALV E
RETUR N SPRING S
TC S ACTUATIO N SIGNA L
FRO M TC S CONTRO L UNI T
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TCS Control Unit Terminal Arrangement

WIRE SIDE OF FEMALE TERMINALS

VB: Battery Voltage
TCS CONTROL UNIT HP CONNECTORProCarManuals.com

TCS CONTROL UNIT 20P CONNECTOR

WIRE SIDE OF FEMALE TERMINALS

VB: Battery VoltageProCarManuals.com

Troubleshooting Precaution s
1. I n an y o f thes e cases , th e TC S indicato r ligh t ma y com e o n o r sta y o n eve n th e TC S syste m is normal .
• Th e coolan t temperatur e is 32° F (0°C ) o r below .
• Th e parkin g brak e is applie d fo r mor e tha n 3 0 second s whil e th e vehicl e is bein g driven .
• Th e tir e pressur e is no t a t th e specifie d pressure .
• Th e whee l senso r signa l i s interrupte d durin g drivin g a t th e spee d o f 6 mp h (1 0 km/h ) o r abov e du e to , fo r example ,
th e vehicl e spinning .
• Th e MA P sensor , coolan t temperatur e sensor , IC M o r th e atmospheri c pressur e senso r syste m o f th e PGM-F I syste m
is faulty .
2. TC S doe s no t functio n whe n th e TC S indicato r ligh t i s ON .
3 . Whe n bot h th e TC S indicato r ligh t an d th e MI L ar e ON , troubleshoo t th e PGM-F I syste m first .
4 . Whe n bot h th e TC S indicato r ligh t an d th e AB S indicato r ligh t ar e ON , troubleshoo t th e AB S first .
5 . Th e DT C 4- 9 (AB S down ) i s memorize d whe n th e AB S contro l uni t canno t outpu t th e whee l spee d signa l du e to , fo r
example , a missin g o r blow n AB S B 2 (1 5 A ) fuse . I f yo u fai l t o eras e th e DT C o f th e TC S afte r troubleshootin g th e ABS ,
th e DT C remain s in th e TC S contro l uni t memory . Therefore , b e sur e to test-driv e th e vehicl e an d chec k th e TC S indica -
to r ligh t befor e startin g th e troubleshootin g th e TCS .
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Diagnostic Troubl e Cod e (DTC )
Diagnosti c Troubl e Cod e (DTC ) Indicatio n
1. Connec t th e SC S servic e connecto r t o th e servic e chec k connecto r unde r th e glov e box .
2. Tur n th e ignitio n switc h O N (II) , bu t d o no t star t th e engine .
3. Recor d th e blinkin g frequenc y o f th e TC S indicato r light . Th e blinkin g frequenc y indicate s th e diagnosti c troubl e cod e
(DTC) .
4. Tur n th e ignitio n switc h off , an d remov e th e SC S servic e connector .
NOTE : Th e Malfunctio n Indicato r Lam p (MIL ) wil l sta y o n afte r th e engin e is starte d i f th e SC S servic e connecto r i s con -
nected .
5 . Perfor m th e DT C erasure .
SCS SERVIC E CONNECTO R07PAZ-001010 0
TCS INDICATO R LIGH T
SERVIC E CHEC KCONNECTO R (2P )
DTC Indicatio n Patter n
Tur n th e ignitio n switc h O N (II) . Th e TC S indicato r ligh t come s o n t o chec k th e bulb . D o no t coun t i t a s a DTC .
Th e TC S contro l uni t ca n memoriz e u p to thre e DTCs .
A ne w DT C is no t memorize d agai n whe n th e TC S contro l uni t ha s alread y memorize d th e sam e DTC .
The TC S contro l uni t indicate s th e DT C repeatedl y a t interval s o f 3. 3 seconds .
I f yo u miscoun t th e blinkin g frequenc y o r i f yo u rechec k th e blinkin g frequency , tur n th e ignitio n switc h OF F the n tur n i t
O N (II ) t o cycl e th e TC S indicato r ligh t again .
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Diagnostic Trouble Code (DTC)

DTC Erasure

1. Pull the parking brake lever up.

2. Push and hold the TCS switch, then turn the ignition switch ON (II).

3. Hold the TCS switch pushed for four seconds (do not release the TCS switch), then release the TCS switch for less than

six seconds.

4. After three seconds, the TCS indicator light go off three times, then turn it on. It means that the DTC is erased.

NOTE:

• Follow these steps exactly. If you connect the SCS service connector and/or release the parking brake lever during

these steps, the DTC will not be erased.

• If the TCS indicator light blinks repeatedly, replace the TCS control unit.

Standard Indication Pattern

Abnormal Indication PatternProCarManuals.com

Troubleshooting Guid e
19-120
19-122
19-123
19-126
19-129
19-134
19-135
19-136
19-137
19-138
19-140
19-142
19-143
19-144
19-145
19-148
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Electronic Component s
Steering Angl e Senso r Replacemen t
CAUTION: D o no t damag e o r dro p th e steerin g angl e senso r a s it i s sensitive .
1 . Remov e th e combinatio n switc h (refe r t o sectio n 1 7 in th e '9 5 - '9 8 Acur a 2.5T L servic e manual , P/ N 61SW504) .
2 . Remov e th e circli p an d screw , the n remov e th e steerin g angl e senso r fro m th e combinatio n switch .
3 . Installatio n i s i n th e revers e orde r o f removal .
CAUTION : D o no t appl y an y greas e o r oi l t o th e steerin g angl e sensor .
4 . Perfor m th e steerin g angl e senso r syste m check . SCRE W
STEERING ANGL E SENSO R
COMBINATIO N SWITC H
CANCE L CA M
WAV E WASHE R
SPRING
LOWER COVE R
NOTE: Whe n reassembling , alig n th e tab s o f th e join t an d
cance l ca m to th e sli t o f th e steerin g angl e sensor .
Steering Angl e Senso r Syste m Chec k
1. Star t th e engine .
2 . Pus h th e TC S switc h thre e time s withi n thre e seconds .
NOTE: Alway s maintai n th e sam e numbe r o f rotations .
3. Slowl y tur n th e steerin g whee l fro m clockwis e mor e tha n 1. 5 turns .
NOTE :
• Star t checkin g afte r th e steerin g whee l move s a t leas t 1. 5 turns .
• Tur n th e steerin g whee l slowly , n o faste r tha n on e tur n in fou r seconds .
4 . Pus h th e TC S switc h twic e withi n thre e seconds .
NOTE : Alway s maintai n th e sam e numbe r o f rotations .
5 . Slowl y tur n th e steerin g whee l counterclockwise , an d chec k th e numbe r o f time s th e TC S indicato r ligh t flashe s afte r
th e whee l ha s move d approximatel y on e turn .
NOTE :
• Star t countin g afte r th e steerin g whee l move s on e turn .
• Tur n th e steerin g whee l slowly , n o faste r tha n on e tur n i n fou r seconds .
Standar d numbe r o f time s th e TC S indicato r ligh t flashes : 2 time s ('9 6 model )
: 4 time s ('9 7 model )
6 . I f ther e is a n abnormality , chec k th e troubleshooting flowchart (se e pag e 19-126 ).
JOIN T
CIRCLI P
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Electronic Components

TCS Control Valve Assembly Replacement

CAUTION: Be careful not to damage the TCS control valve when handling the TCS control valve assembly.

1. Disconnect the vacuum tube, breather pipe and air hose from the intake air duct.

2. Loosen the intake air duct band screws, then remove the intake air duct.

BREATHER PIPE

AIR HOSE

NOTE: When installing the duct,

align the marks.
NOTE: When installing the duct,

align the cutout with mark.

VACUUM TUBE

INTAKE AIR DUCT

BAND SCREW

INTAKE AIR DUCT

3. Disconnect the TCS control valve angle sensor connector and actuator connector.

4. Remove the TCS control valve assembly and bracket.

5. Install the TCS control valve assembly in the reverse order of removal.

TCS CONTROL VALVE ANGLE

SENSOR CONNECTOR
6 x 1.0 mm BOLT

12 N-m (1.2 kgf-m, 9 Ibf-ft)

TCS CONTROL VALVE

ASSEMBLY

8 x
1.25
mm NUT

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

8 x 1.25 mm BOLT

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

BRACKET
TCS CONTROL VALVE

ACTUATOR CONNECTORProCarManuals.com