sensor ACURA TL 1995 Service Service Manual

Differential Assembl y
Removal (cont'd )
6. Remov e th e righ t fron t bea m bridge .
RIGHT FRON T BEA M BRIDG E
7. Disconnec t th e vehicl e spee d senso r (VSS ) con -
necter , the n remov e th e VSS/powe r steerin g spee d
sensor .
NOTE: D o rio t disconnec t th e hoses .
VSS CONNECTE R
VSS/POWE R STEERIN G
SPEE D SENSO R
8. Remov e th e mountin g bolt s an d 2 6 m m shim , the n
remov e th e differentia l assembly .
O-RINGReplace .
DIFFERENTIA LASSEMBLY
26 m m SHI M
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Differential Assembl y
Installatio n (cont'd )
8. Instal l th e vehicl e spee d senso r (VSS)/powe r steer -
in g spee d sensor , the n connec t th e VS S connecter .
VSS CONNECTE R
6 x 1. 0 m m12 N- m (1. 2 kgf-m , 8. 7 Ibf-ft )
VSS/POWE R STEERIN G
SPEE D SENSO R
9. Instal l th e righ t fron t bea m bridge .
10 x 1.2 5 mm38 N- m (3. 9 kgf-m , 2 8 Ibf-ft )
RIGH T FRON T BEA M BRIDG E
10. Remov e th e steerin g gearbo x mountin g bolts , the n
instal l th e lowe r plat e an d th e steerin g gearbo x
mounting bolts .
STEERIN G GEARBO XMOUNTING BOLT S59 N- m (6. 0 kgf-m ,
4 3 Ibf-ft )
10 x 1.2 5 mm38 N- m (3. 9 kgf-m ,28 Ibf-ft )
11. Instal l th e splas h shiel d
SPLAS HSHIELD •
LOWE R
PLATE
6 x 1. 0 m m9.8 N- m (1. 0 kgf-m ,
7. 2 Ibf-ft )
12. Instal l th e driveshaft s an d th e intermediat e shaf t
(se e sectio n 16 ).
13 . Refil l th e differentia l wit h oi l (se e pag e 15-4 ).
14 . Chec k th e fron t whee l alignmen t (se e sectio n 18 ).
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Power Steering Hoses and Pipes

Replacement

NOTE:

• Slide each hose over the corresponding pipe up to

the stop on the pipe. Install the clamp or adjustable

clamp at the specified distance from the hose end as

shown.

• Add the power steering fluid to the specified level on

the reservoir and check for leaks (refer to the '95 - 98

Acura 2.5TL Service Manual, P/N 61SW504).
CAUTION: Check all clamps for deterioration and defor-

mation; replace the clamps with new ones if necessary.

ADJUSTABLE HOSE CLAMP:
HOSE CLAMP:

Slide the hose over the pipe until it contacts the

stop.
Slide the hose over the pipe until it contacts the

stop.

2.5
-
5.5
mm

(0.01
-
0.22
in)
2.0
-
4.0
mm

(0.08
-
0.16
in)
2.5
-
5.5
mm

(0.01- 0.22 in)

INLET HOSE
RETURN HOSE

RESERVOIR

SENSOR RETURN HOSE

RETURN HOSE

SENSOR RETURN

HOSE

VALVE BODY UNIT

16 mm FLARE NUT

28 N-m (2.9 kgf-m, 21 Ibf-ft)

12 mm FLARE NUT

13 N-m (1.3 kgf-m, 9 Ibf-ft)

RETURN LINE
FEED LINE

(OUTLET HOSE)

11 N-m

(1.1 kgf-m 8 Ibf-ft)

PUMP

SENSOR INLET

HOSE

SENSOR INLET

LINE

POWER STEERING

SPEED SENSOR
FEED LINE
11 N-m (1.1 kgf-m,

8 Ibf-ft)
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Steering Gearbo x
Remova l (cont'd )
11. Disconnec t th e tw o line s (fee d lin e an d senso r
retur n line ) fro m th e valv e bod y uni t uppe r side .
CAUTION : Afte r disconnectin g th e pipes , plu g o r
sea l th e lin e fitting s wit h a piec e o f tap e o r equiva -
len t t o preven t foreig n material s fro m th e enterin g
th e valv e bod y unit :
FEED LIN E(Fro m th e pump )
SENSO R RETUR N LIN E
(T o th e reservoir )
12. Disconnec t th e tw o line s (senso r inle t lin e an d
retur n line ) fro m th e valv e bod y uni t lowe r side .
NOTE : I t i s no t necessar y t o loose n cylinde r line s A
an d B betwee n th e valv e bod y uni t an d th e cylinder ,
(see pag e 17-11 )
12 m m FLAR E NU T
17 m m FLAR E NU T SENSO
R INLE T LIN E
(T o th e powe r steerin g
spee d sensor )
RETUR N LIN E
(T o th e reservoir )
13. Remov e th e righ t mountin g bracke t an d steerin g
gearbox .
NOTE : Befor e removin g th e gearbox , plac e a jac k
stan d unde r th e gearbox.
CAUTION : B e carefu l no t t o ben d o r damag e cylin -
de r line s A an d B whe n removin g th e steerin g gear -
box.
RIGH T MOUNTIN GBRACKET
STEERIN G GEARBO X
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6. Reconnec t th e tw o line s (fee d lin e an d senso r line )
t o th e uppe r sid e o f th e valv e bod y unit .
FEED LIN E
(Fro m th e pump ) 1
1 N- m (1.1kgf-m ,
8 Ibf-ft )
SENSO R RETUR N LIN E
(T o th e reservoir )
7. Reconnec t th e tw o line s (senso r inle t lin e an d retur n
line )
to th e lowe r sid e of th e valv e bod y unit.
SENSO R INLE T HOS E(To th e powe r steerin g
12 m m FLAR E NU T speed sensor )13 N- m (1. 3 kgf-m , 9 Ibf-ft )
1 7 m m FLAR E NU T
2 8 N- m (2. 9 kgf-m , 2 1 Ibf-ft )
RETUR N LIN E
(T o th e reservoir )
8. Instal l th e lin e mountin g cushion s b y alignin g th e
pin k mark s o n th e retur n lin e (larg e diamete r line) .
NOTE : Afte r installin g th e pip e mountin g cushions ,
mak e sur e tha t ther e is n o interferenc e betwee n th e
line s an d rea r beam .
9. Instal l th e tw o lin e clamp s o n th e lin e mountin g
cushions.PINK MARK S
RETUR N LIN E
9.8 N- m(1.0 kgf-m , 7 Ibf-ft )
LINE MOUNTIN GCUSHIONS
LIN E CLAM P
NOTE: Mak e sur e tha t ther e is n o interferenc e betwee n
th e flui d lines , th e rea r bea m or an y othe r parts .
10 . Tighte n th e tw o gearbo x mountin g bolt s o n th e
righ t sid e tha t wer e loosel y installe d in ste p 2 .
11 . Instal l th e splas h guar d wit h th e tw o gearbo x
mountin g bolt s o n th e lef t side .
12 . Tighte n th e splas h guar d attachin g bolts .
NOTE : Instal l th e bolt s loosel y first , the n tighte n
SPLAS H GUAR D
GEARBO X MOUNTIN G BOLT S
5 9 N- m (6. 0 kgf-m , 4 3 Ibf-ft )
SPLAS
H GUAR D MOUNTIN G
BOLTS38 N- m (3. 9 kgf-m , 2 8 Ibf-ft )
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Diagnostic Troubleshootin g Cod e (DTC )
Symptom-to-Syste m Char t (cont'd )
Right-front
Left-fron t
Right -rear
Left -rear
Right -front
Left -
fron t
Right -rear
Left -rear
Right /Left
Righ t
Left
Front /rear
Fron t
Rear
Right -front
Left -
fron t
Rea r
• Chippe d pulse r gea r
• Improperl y installe d whee l senso r
• Differen t diamete r tir e installe d
• Ope n circuit , interna l shor t o r shor t t o bod y groun d i n th e whee l
sensor• Ope n circui t o r shor t t o bod y groun d i n th e positiv e ( + ) wir e be -
twee 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 be -
twee n th e whee l senso r an d AB S contro l uni t
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
• Imprope r whee l senso r ai r ga p
• Fault y AB S contro l uni t
• Missin g pulse r
• Modulato r doe s no t decreas e pressur e properl y
• Ope n circuit , interna l shor t o r shor t t o bod y groun d i n th e whee l
senso r syste m
• Rea r brak e dra g• Modulato r doe s no t decreas e pressur e properl y
• Fault y AB S contro l uni t
• Shor t t o powe r i n th e rela y driv e circui t betwee n th e fail-saf e rela y
an d AB S contro l uni t
• Fault y rela y driv e transisto r (ON ) i n th e AB S contro l uni t
• Fail-saf e rela y stuc k O N
• Shor t t o powe r i n th e solenoi d driv e circuits betwee n th e fail-saf e
rela y an d AB S contro l uni t
• Fail-saf e rela y stuc k OF F
• Ope n circui t i n th e solenoi d driv e circui t betwee n th e under-hoo d
fuse/rela y bo x an d AB S contro l uni t
• Shor t t o bod y groun d i n th e solenoi d driv e circui t betwee n th e
solenoi d an d AB S contro l uni t
• Fault y solenoi d driv e transisto r (ON ) i n th e AB S contro l uni t
• Shor t t o powe r i n th e solenoi d driv e circui t betwee n th e solenoi d
an d AB S contro l uni t
• Fault y solenoi d driv e transisto r (OFF ) i n th e AB S contro l uni t
• Shor t t o powe r i n th e driv e circui t insid e th e solenoi d
• Shor t t o th e outle t circui t i n th e inle t circui t betwee n th e solenoi d
an d AB S contro l uni t
• Whee l 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
• Faulty ABS contro l uni t
• Fault y AB S contro l uni t
• Intermitten t interruptio n i n th e whee lsensor
• (N o problem )
• Intermitten t interruptio n i n th e whee l
sensor• Whee l spi n o f bot h fron t wheel s (onl y
fo r DT C 4-8 ) — (No problem )
• Th e transmissio n downshifte d
excessivel y (onl y fo r DT C 4- 1 an d
4-2 ) -(N o problem )
• Intermitten t interruptio n i n th e whee l
sensor• Whee l spi n b y operatin g th e parkin g
brak e whil e th e parkin g brak e switc h
i s stuc k OF F
• Ca r spun-out — (N o problem )
• Intermitten t interruptio n i n th e sole -
noi d valv e driv e circui t
• Intermitten t interruptio n i n th e sole -
noi d valv e groun d circui t
• Intermitten t interruptio n i n th e fail -
saf e rela y circui t
• Intermitten t interruptio n i n th e whee l
sensor• Roug h roa d drivin g — (N o problem )
• (N o problem )
• (N o problem ) •
Th e AB S indicato r ligh t i s turne d o n whe n th e whee l senso r signa l i s periodicall y
missin g durin g driving .
• Th e AB S indicato r ligh t ma y b e turne d o n whil e drivin g whe n one , tw o o r thre e
differen t diamete r tire s ar e installed .
Thi s diagnosi s i s no t performe d whe n th e parkin g brak e switc h i s ON .
• Th e AB S indicato r ligh t i s turne d o n whe n th e whee l senso r signa l i s missin g 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 switc h i s ON .
• Th e AB S indicato r ligh t i s turne d o n whe n eithe r o r bot h rea r wheel s loc k an d
th e whee l senso r signa l i s missin g durin g driving .
Thi s diagnosi s i s no t performe d whe n th e parkin g brak e switc h i s ON .
• Th e AB S indicato r ligh t i s turne d o n whe n batter y voltag e i s detecte d a t th e
solenoi d termina l befor e th e fail-saf e relay s ar e turne d o n a t th e initia l diagnosis .
• Eac h solenoi d valv e i s momentaril y activate d a t th e initia l diagnosi s an d whe n
th e ca r start s off . Th e AB S indicato r ligh t i s turne d o n whe n batter y voltag e i s
detecte d a t th e solenoi d terminal .
• Th e AB S indicato r ligh t i s turne d o n whe n 0 V is detecte d a t th e solenoi d termi -nal whil e th e solenoi d OF F signa l i s detecte d a t th e regula r diagnosis .
• Th e AB S indicato r ligh t i s turne d o n whe n th e AB S function s continuously .
• Th e AB S indicato r ligh t i s turne d o n whe n ther e i s a differenc e betwee n th e
CP U data .
• Th e AB S indicato r ligh t i s turne d o n whe n ther e i s a abnormalit y i n th e I C a t th e
regula r diagnosis .
19-37
19-3 7
19-3 8
19-4 1
19-4 2
19-4 4
19-4 7
19-4 9
19-5 3
19-5 9
19-6 6
19-6 7
19-6 7
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Operation 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 O mp h ( O km/h ) 11 3 mp h (18 0 km/h ) O mph ( O 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
Mod e 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
Mod e 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
Mod e 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
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
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 during the 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
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System Descriptio n
Outline
Role o f Syste m
Th e tractio n contro l i s a variabl e syste m designe d t o enhanc e tractio n durin g acceleratio n an d cornering . I t doe s s o b y
determinin g th e optimu m amoun t o f whee l spi n fo r an y give n drivin g situation , the n suppressin g surplu s engin e powe r
accordingly .
Constructio n an d Functio n
The TC S contro l uni t get s signal s abou t th e vehicle' s speed , direction , an d roa d condition s fro m sensor s a t th e wheel s an d
the steerin g column . Base d o n thes e signals , th e contro l uni t wil l determin e th e optimu m amoun t o f whee l spin . Becaus e
th e syste m is variable , th e contro l uni t ma y determine , dependin g o n th e drivin g conditions , tha t som e whee l spi n i s bene -
ficia l (thu s enhancin g straight-lin e acceleration) , o r tha t n o whee l spi n i s beneficia l (thu s enhancin g cornering) . Fo r an y
give n drivin g situation , th e contro l uni t wil l determin e th e amoun t o f whee l spi n bes t suite d t o th e driver' s need s and , i f
necessary , wil l the n signa l th e TC S contro l valv e actuato r an d Powertrai n Contro l Modul e (PCM ) t o reduc e engin e power .
Th e syste m is automaticall y "ready " wheneve r th e engine is started , bu t ca n b e manuall y cancele d wit h th e TC S switch .
However , onc e activated , th e syste m canno t b e cancele d unti l i t i s onc e agai n i n th e read y state .
SERVIC E CHEC K CONNECTO R (2P )ABS CONTRO L UNI TTCS CONTRO L UNI TUNDER-DAS H RELA Y BO X
POWERTRAI N
CONTRO L MODUL E (PCM )
EC T SENSO R
TC S CONTRO L VALV E
ANGL E SENSO R STEERIN
G ANGL E SENSO R
RIGHT-REA R WHEE L SENSO R
RIGHT-FRON T
WHEE L SENSO R
Components :
• Whee l sensors : Th e TC S "shares " th e whee l sensor s wit h th e ABS . Th e whee l sensor s transmi t whee l spee d signal s t o
th e TC S throug h th e AB S contro l unit .
• Steerin g angl e sensor : Th e steerin g angl e senso r signal s th e TC S contro l uni t abou t th e amoun t o f steerin g angle .
• TC S contro l valv e sensor : Th e TC S contro l valv e senso r signal s th e TC S contro l uni t abou t th e amoun t o f TC S contro l
valv e angle .
• TC S contro l valv e actuator : Th e actuato r get s signal s fro m th e TC S contro l uni t an d close s th e TC S contro l valv e
accordingly .
• TC S contro l unit : Th e TC S contro l uni t detect s th e drivin g conditio n signal s fro m th e sensor s and , i f necessary , signal s
th e Powertrai n Contro l Modul e (PCM) .
LEFT-REA RWHEEL SENSO R
UNDER-HOO D FUSE/RELA Y BO X
LEFT-FRON
T WHEE L SENSO R
TC
S CONTRO L
VALV E ACTUATO R UNDER-DAS
H FUSE/RELA Y BO X
TC
S SWITC H
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Construction and Function

TCS Control unit

Driving Control

When the drive wheel speed exceeds the vehicle speed by a given amount, the TCS control unit judges that the drive

wheels are slipping, and it outputs the traction control signal to reduce engine power.

Handling Control

Based on signals about right and left driven wheel rotational speeds, the control unit calculates the vehicle's "yaw" rate

(the turn rate of the vehicle's body). Based on signals from the steering angle sensor, the control unit also calculates the

yaw rate expected by the driver. If the difference between actual and expected yaw rates is substantial — that is, if the

direction of the vehicle's body will exceed the driver's expected line — the control unit signals the TCS control valve actu-

ator and PCM, thus reducing engine power and maintaining the expected line.

Rough Road Control

Based on signals from the wheel sensors, the control unit detects a rough road based on frequency of wheel rotational

vibration. The control unit then signals the TCS control valve actuator and PCM to relax engine power, thus improving

acceleration efficiency.

Grip Control

Based on signals about wheel speed and yaw rate, the control unit determines the efficiency of the grip of the tires on the

road and signals the TCS control valve actuator and PCM to relax engine power, if necessary, thus improving grip.

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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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