1996 ACURA RL KA9 wheel

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
light t o com e on . Howeve r i f th e abnormalit y is detecte d
while 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
the syste m down , thu s preventin g excessiv e whee l spin .
Self-Diagnosi s Functio n
If 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 is detecte d b y th e steerin g angl e sensor .
A dis c wit h a regula r patter n o f slit s is positione d betwee n
th e facin g part s o f a ligh t emittin g par t (LED) , an d a ligh t
receivin g par t (phot o transistor) . As the dis c rotates , i t
interrupt s th e ligh t fro m th e LED . Th e ligh t whic h passe s
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 wavefor m o f thi s electri c cur -
ren t i s shape d b y th e comparato r t o outpu t th e dis c rota -
tio n a s a 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 transistor .
Th e outpu t signa l i s a 2-phas e outpu t (A-phas e an d Bi -
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 -
trol unit , whic h compare s eac h wheel' s spee d an d deter -
mines whethe r tractio n contro l i s required .
FIXED SLI T
LIGH T EMITTIN G PAR T (LED )
TCS INDICATO R LIGH T
LIGHT RECEIVIN G PAR T(PHOT O TRANSISTOR )
SLIT
Steerin g whee l i s
turne d to right .
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TCS Control Unit Terminal Arrangement

TCS CONTROL UNIT 14P CONNECTOR

Wire side of female terminals

VB: Battery Voltage

Terminal

number

1

2

3

4

5

6

7

8

9

10

11

12

13

14
Wire

color

WHT/GRN

BLU/GRY

WHT/RED

BRN/BLK

GRY/BLK

RED

GRY/WHT

LT

GRN/RED

GRY

PNK/BLK

WHT/BLK

BLU/WHT

BRN/YEL

RED/BLK
Terminal sign

(Terminal name)

FRP

(Front right pulse)

WARN1

(Warning 1)

FLP

(Front left pulse)

LG1

(Logic ground 1)

RRP

(Rear right pulse)

TCV

( traction

control valve)

RLP

(Rear left pulse)

TC-INH

(Traction control

inhibit)

STR-B

(Steering B)

TC-STB

(Traction control

standby)

TC-SW

(Traction control

switch)

VREF

(Voltage

reference)

STR-A

(Steering A)

TPS

(Throttle posi-

tion sensor)
Description

Detects right-front

wheel sensor signal

Drives TCS indicator

light (The indicator light

comes on by the

self-bias)

Detects left-front wheel

sensor signal

Ground for the logic

circuit

Detects right-rear wheel

sensor signal

Detects TCS control

valve sensor signal

Detects left-rear wheel

sensor signal

Fl TCS, TCS opera-

tion permission signal

Detects steering angle

sensor signal B

TCS Fl, TCS opera-

tion start signal

Detects TCS switch

signal

Reference voltage for

the sensors of the

PGM-FI system

Detects steering angle

sensor signal A

Detects throttle position

sensor signal
Voltage

Measurement

terminals

1-GND

2-GND

3-GND

4-GND

5-GND

6-GND

7-GND

8-GND

9-GND

10-GND

11-GND

12-GND

13-GND

14-GND
Conditions

(Ignition Switch ON (ID)

Rotate the right-front

wheel.

Indicator light ON

Indicator light OFF

Rotate the left-front

wheel.

Rotate the right-rear

wheel.

TCS control valve is

fully closed.

TCS control valve is

fully open.

Rotate the right-rear

wheel.

Permission (normal)

Inhibition (the coolant

temperature is 0°C or

below)

Failure (TCS and/or

PCM is failure)

Rotate the steering

wheel.

TCS is functioning.

TCS is not functioning.

Push the TCS switch.

Release the TCS switch.

Rotate the steering

wheel.

Throttle valve is fully

closed.

Throttle valve is fully

open.
Output

voltage

About 2.5 V

About 2 V

VB

About 2.5 V

Below 0.3 V

About 2.5 V

About 0.5V

About 4.5 V

About 2.5 V

About 2.5V

(5 V. Duty 50)

About 5 V

About 0 V

5V 0V

0V

About 5 V

VB

0V

About 5 V

5V 0V

About 0.5 V

About 4.5 VProCarManuals.com

Troubleshooting Precautions

1. In any of these cases, the TCS indicator light may come on or stay on even the TCS system is normal.

The coolant temperature is 32°F (0°C) or below.

The parking brake is applied for more than 30 seconds while the vehicle is being driven.

The tires are not inflated to the specified pressure.

The wheel sensor signal is interrupted during driving at speeds of 6 mph (10 km/h) or above due to, for example, a

vehicle spinning.

The MAP sensor, the coolant temperature sensor, the ICM or the atmospheric pressure sensor system of the PGM-FI

system is faulty.

2. TCS does not function when the TCS indicator light is ON.

3. When both the TCS indicator light and the MIL are ON, troubleshoot the PGM-FI system first.

4. When both the TCS indicator light and the ABS indicator light are ON, troubleshoot the ABS first.

5. The DTC 4-9 (ABS down) is memorized when the ABS control unit cannot output the wheel speed signal due to, for

example, a missing or blown ABS B2 (15 A) fuse. If you fail to erase the DTC of the TCS after troubleshooting the ABS,

the DTC remains in the TCS control unit memory. Therefore, be sure to test-drive the vehicle, and check the TCS indica-

tor light before starting to troubleshoot the TCS.ProCarManuals.com

Troubleshooting
Steering Angl e Senso r
Diagnosti c Troubl e Cod e (DTC ) 2-1 : Steerin g Angl e Senso r Diagnosi s
The TC S contro l uni t perform s th e self-diagnosi s fo r th e steerin g angl e senso r whe n th e spee d o f th e fou r wheel s exceed s
6 mp h (1 0 km/h ) o n a smoot h road . Th e TC S indicato r ligh t come s o n if a ya w rat e is generated , th e correspondin g steer -
ing angl e signa l i s no t inpu t whe n th e steerin g whee l i s turned , an d ther e is n o inpu t fro m th e STO P (brak e peda l positio n
switch signal ) an d PAR K (parkin g brak e switc h signal) .
With engin e running , TC S indi -
cato r ligh t i s ON .
Th e tir e pressur e i s correct ,
an d tire s wit h a correc t diame -
te r ar e installed .
Wit h th e SC S servic e connec -
to r connecte d (se e pag e
19-159 ), DT C 2- 1 is indicated .
Chec k fo r a shor t t o bod y groun d
i n th e wire s betwee n th e TC S con -
tro l uni t an d steerin g angl e sensor :
1 . Disconnec t th e TC S contro l uni t
14P an d 20 P connector s an dsteerin g angl e senso r connec -tor.2. Chec k fo r continuit y betwee n
bod y groun d an d TC S contro l
unit 14 P connecto r terminal sNo. 9 an d No . 1 3 individuall yand betwee n th e 20 P connec -
to r termina l No . 4 an d No . 1 6
individually .
Is ther e continuity ?
Chec k th e STR-VC C circui t insid e
th e TC S contro l unit :
1 . Connec t th e TC S contro l uni t
14 P an d 20 P connectors .
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 . 1 6 an dbod y ground .
Is ther e abou t 5 V ?
Chec k th e STR-GN D circui t insid e
th e TC S contro l unit :
Measur e th e voltag e betwee n th e
TC S contro l uni t 20 P connecto r ter -
mina l No . 4 an d No . 16 .
Is ther e abou t 5 V ?
T o pag e 19-16 9 TC
S CONTRO L UNI T 14 P CONNECTO R
Wir e sid e o f femal e terminal s
TC S CONTRO L UNI T 20 P CONNECTO R
Repair shor t t o bod y groun d in th ewire(s ) betwee n th e TC S contro l
uni t an d steerin g angl e sensor . Wir
e sid e o f femal e terminal s
Replac e th e TC S contro l unit .
Replac e th e TC S contro l unit .
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PGM-FI DTC : 3 5 (TC-ST B signa l doe s no t matc h TC-F C signal )
Check fo r a shor t t o bod y groun d
i n th e TC-ST B circuit :
1 . Disconnec t th e PC M connec -
to r C (12P ) an d TC S contro l
uni t 14 P connectors .
2 . Chec k fo r continuit y betwee n
th e TC S contro l uni t U P con -
necto r termina l No . 1 0 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 ther e continuity ? 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 .
TCS CONTRO L UNI T 20 P CONNECTO R
Chec k fo r a shor t t o bod y groun d
i n th e TC-F C circuit :
1 . Disconnec t th e TC S contro l
uni t 20 P connector .
2 . Chec k fo r continuit y betwee n
termina l No . 1 4 an d bod y
ground .
Is ther e continuity ?Repair 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 . Wir
e sid e o f femal e terminal s
Chec k th e TC S contro l uni t (TC -
STB) :1. Connec t th e TC S contro l uni t
14 P an d 20 P connector s an d
PC M connecto r C (12P) .
2 . Rais e th e fron t o f th e vehicle ,
and suppor t i t wit h safet ystands.
3 . Star t th e engine .
4 . Measur e th e voltag e betwee n
th e TC S contro l uni t 14 P con -
necto r termina l No . 1 0 an d
bod y ground . TC
S CONTRO L UNI T U P CONNECTO R
Wir e sid e o f femal e terminal s
I s th e voltag e a s specified ?
TCS is functioning :about 0 V
TC S is no t functioning :
abou t 5 V Chec
k fo r loos e TC S contro l uni t
connectors . I f necessary , substi -
tut e a known-goo d TC S contro l
uni t an d recheck .
To pag e 19-17 4
NOTE : Sto p th e wheel s b y depressin g
th e brak e peda l lightly .
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Troubleshooting
PGM-FI DTC : 3 5 (TC-ST B signa l doe s no t matc h TC-F C signal ) (cont'd )
From pag e 19-17 3
Chec k th e TC S contro l uni t (TC -
FC):Measur e th e voltag e betwee n th eTC S contro l uni t 20 P connecto rterminal No . 1 4 an d bod y ground .NOTE
: Us e th e 1 0 V rang e o r a simila r
rang e in a n analo g tester .
TCS IS NO T TC S ISFUNCTIONIN G FUNCTIONIN G
TCS CONTRO L UNI T 20 P CONNECTO R
Check fo r loos e TC S contro l uni tconnectors . I f necessary , substi -tute a known-goo d TC S contro l
uni t an d recheck .
NOTE : Sto p th e wheel s b y depressin g
th e brak e peda l lightly .
Check fo r a n ope n i n th e TC-ST Bcircuit:Measur e th e voltag e betwee n th e
PC M connecto r C (12P ) termina l
No. 1 2 an d bod y ground .
Wire sid e o f femal e terminal s
PC M CONNECTO R C (12P )
I s ther e abou t 5 V whe n TC S is
no t functioning ? Repai
r ope n in th e wir e betwee n
th e TC S contro l uni t an d PCM . Wir
e sid e o f femal e terminal s
Check fo r a n ope n i n th e TC-F Ccircuit :
Measur e th e voltag e betwee n th e
PC M connecto r C (12P ) termina lNo. 1 0 an d bod y ground . NOTE
: Us e th e 1 0 V rang e o r a simila r
rang e in a n analo g tester .
TCS IS NO T TC S ISFUNCTIONIN G FUNCTIONIN G
I s ther e abou t 4. 5 V whe n TC S is
no t functioning ? Repai
r ope n in th e wir e betwee n
th e TC S contro l uni t an d PCM .
Chec k fo r loos e PC M connectors .
I f necessary , substitut e a known -
goo d PC M an d recheck .
TC
S is functionin g (maximum) :
abou t 1.5 V
TC S is no t functioning :
abou t 4. 5 V
I
s th e voltag e a s specified ?
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Troubleshooting
Wheel Senso r
Diagnosti c Troubl e Cod e (DTC ) 4- 1 (Right-front) , 4- 2 (Left-front) , 4- 4 (Right-rear) , 4- 8 (Left-rear) :
Wheel Senso r Diagnosi s
The TC S indicato r ligh t come s o n whe n th e averag e spee d o f eithe r th e righ t o r lef t rea r wheel s exceed s 9 mp h (1 5 km/h )
and th e AB S contro l uni t signa l stop s fo r mor e tha n 3 seconds .
With engin e running , TC S indi -
cato r ligh t i s ON .
ABS indicato r ligh t is OFF .With th e SC S servic e connec -
to r connecte d (se e pag e
19-159 ), DTC s 4-1 , 4-2 , 4- 4 and/o r
4- 8 ar e indicated . NOTE
: Whe n bot h th e TC S indicato r
light an d th e AB S indicato r ligh t ar e ON ,troubleshoo t th e AB S first .
Confir m th e AB S DT C
('9 6 - 9 7 models : se e pag e 19-4 0
'98-9 9 models : se e pag e 19-119 )
'9 6 -9 7 models :
I s cod e 4-1 , 4-2 , 4-4 and/o r 4- 8
indicated ?
'9 8 - 9 9 models :
I s cod e 11 , 13 , 1 5 and/o r 1 7
indicated ? Perfor
m th e appropriat e AB S trou -
bleshootin g fo r th e cod e (se e pag e
19-65 o r 19-126 ).
* 1 '96-9 7 model s*2 '9 8 -9 9 model s
TC S CONTRO L UNI T 14 P CONNECTO R
Chec k fo r a n shor t t o bod y groun d
i n th e FRP , FLP , RR P and/o r RL P
circuit :1. Tur n th e ignitio n switc h OFF .2. Disconnec t th e TC S contro lunit 14 P an d AB S control unit26P o r 22 P connectors .
3 . Chec k fo r continuit y betwee n
the TC S contro l uni t 14 P con -necto r appropriat e terminal *
an d bod y ground .
Is ther e continuity ?Repair shor t t o bod y groun d i nth e wir e betwee n th e TC S con -trol uni t an d AB S contro l unit . Wir
e sid e o f femal e terminal s
Chec k th e TC S contro l unit :
1 . Connec t th e TC S control unit
connector .
2 . Tur n th e ignitio n switc h O N (II) .
3 . Measur e th e voltag e betwee n
the TC S contro l uni t connec -tor appropriat e terminal * an dbody ground .
Is ther e abou t 5 V ?
T o pag e 19-18 3 Chec
k fo r loos e TC S contro l uni t
connectors . I f necessary , substi -
tut e a known-goo d TC S contro l
uni t an d recheck .
DT
C Appropriat e Termina l
4- 1 (Right-front ) No . 1 : FR P
4-2 (Left-front ) No . 3 : FL P
4-4 (Right-rear ) No . 5 : RR P
4- 8 (Left-rear ) No . 7 : RL P
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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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