1996 ACURA RL KA9 sensor

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 .
ProCarManuals.com

Engine Output Control

When the TCS is activated, the TCS control unit signals the TCS control valve actuator and PCM. The actuator is linked to

the TCS control valve which is normally returned to the fully open position by the two return springs. Although the throttle

valve is still within the driver's control, the engine output is relaxed by the TCS control valve and PCM to achieve optimum

traction.

TCS CONTROL VALVE SENSOR

TCS CONTROL VALVE
TCS CONTROL VALVE

RETURN SPRINGS

TCS CONTROL VALVE

ACTUATOR (DC MOTOR)

DURING NORMAL DRIVING:
DURING TCS ACTUATION:

TCS CONTROL VALVE

TCS CONTROL VALVE

ACTUATOR (DC MOTOR)
TCS CONTROL VALVE

RETURN SPRINGS

TCS ACTUATION SIGNAL

FROM TCS CONTROL UNITProCarManuals.com

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

TCS CONTROL UNIT 20P CONNECTOR

Wire side of female terminals

VB: Battery Voltage

Terminal

number

1

2

4

5

6

9

10

11

12

13

14

15

16

17

20
Wire

color

BLK/YEL

GRN/RED

BLU

PNK/BLU

BLK/WHT

BLK

BRN/WHT

GRN/WHT

BLU

GRN/ORN

BLK/ORN

BRN/BLK

WHT/BLU

BLU/GRY

GRN

BRN
Terminal sign

(Terminal name)

IG1

(Ignition 1)

PARK

(Parking)

SCS

(Service check

signal)

STR-GND

(Steering ground)

AT-SHIFT

(AT shift)

FSR

(Fail-safe relay)

PMG

(Power motor

Ground)

VPM

(Voltage power

motor)

STOP

(Stop)

NEP (Engine

speed pulse)

BARO

(Barometric)

TC-FC

(Traction control

fuel cut)

LG2

(Logic ground 2)

STR-VCC (Steer-

ing power supply)

WARN2

(Warning 2)

SH-MOT

(Shield motor)

MOT +

(Motor +)

MOT-

(Motor -)
Description

Detects ignition switch

IG1 signal

Detects parking brake

switch signal

Detects service check

connector signal

(Diagnostic trouble

code indication)

Ground for the steering

angle sensor

Detects A/T shift posi-

tion signal

Drives fail-safe relay

Power ground for the

TCS control valve

actuator motor

Power source for the

TCS control valve

actuator motor

Detects brake pedal

position switch signal

Detects engine speed

signal

Detects barometric

sensor signal

TCS Fl, Fuel cut

(torque down) signal

Ground for the logic

circuit

Power source for the

steering angle sensor

Drives TCS indicator light

(The indicator light comes

on by the self-bias)

Shield for the TCS con-

trol valve actuator motor

Drives TCS control

valve actuator motor

Drives TCS control

valve actuator motor
Measurement

terminals

1-GND

2

3-GND

4-GND

5-GND

6-GND

9-GND

10-GND

11-GND

12-GND

13-GND

14-GND

15-GND

16-GND

17-GND

19-20

20-19
Voltage

Conditions

(Ignition Switch ON (II))

Depress the parking

brake pedal.

Release the parking

brake pedal.

SCS service connector

connected.

SCS service connector

disconnected.

Shift the transmission

to position, then

start the engine.

Start the engine.

Start the engine.

Brake pedal depressed.

Brake pedal released.

Engine idling

TCS is functioning,

(maximum fuel cut)

TCS is not functioning.

Indicator light ON

Indicator light OFF

TCS is functioning.

TCS is not functioning.

TCS is functioning.

TCS is not functioning.
Output

voltage

VB

Below 0.6 V

VB

0V

5V

Below 0.3V

About 4V

(5V 0V)

VB

1.5V

Below 0.3 V

0V

VB

VB

0V

About 6V

(12V
0V)

About 3 V

About 1.5V

About 4.5 V

(5 V,
PWM)

Below 0.3V

About 5 V

About 2 V

VB

VB

0V

VB

0VProCarManuals.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 .
ProCarManuals.com

From pag e 19-16 8
Chec k fo r a n ope n in th e STR-VC C
circuit :
Measur e th e voltag e betwee n th e
steerin g angl e senso r connecto r
terminal No . 5 an d bod y ground .
Is ther e abou t 5 V ?
Chec k fo r a n ope n i n the STR -
GN D circuit :
Measur e th e voltag e betwee n th e
steerin g angl e senso r connecto r
terminals No . 5 an d No . 1 .
Is ther e abou t 5 V ?
Chec k th e STR- A circui t insid e th e
steerin g angl e sensor :
1. Tur n th e ignitio n switc h OFF .2. Connec t th e steerin g angl e sen -
so r connector .
3. Tur n th e ignitio n switc h O N (II) .4. Measur e th e voltag e betwee n
th e steerin g angl e senso r con -
necto r termina l No . 2 an d bod y
groun d whe n turnin g th e steer -
ing whee l slowly .
Is ther e 5 V 0 V ?
Chec k th e STR- B circui t insid e
th e steerin g angl e sensor :
Measur e th e voltag e betwee n th e
steerin g angl e sensor connecto r
terminal No . 4 an d bod y groun dwhen turnin g th e steerin g whee lslowly.
Is ther e 5 V 0 V ?
T o pag e 19-17 0 STEERIN
G ANGL E SENSO R CONNECTO R
Repai r ope n in th e wir e 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
Repai r ope n i n th e wir e betwee n
th e TC S contro l uni t an d steerin g
angl e sensor .
Replac e th e steerin g angl e sensor .
Replac e th e steerin g angl e sensor .
ProCarManuals.com

Troubleshooting
Steering Angl e Senso r (cont'd )
From pag e 19-16 9
Chec k fo r a n ope n i n th e STR- Acircuit:Measur e th e voltag e betwee n th e
TC S contro l uni t 14 P connecto r
termina l No . 1 3 an d bod y groun d
whe n turnin g th e steerin g whee l
slowly.
Is ther e 5 V 0 V?
Chec k fo r a n ope n in th e STR- B 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 . 9 an d bod y groun d
when turnin g th e steerin g whee lslowly .
Is ther e 5 V 0 V? Repai
r ope n in th e wir e betwee n
th e TC S contro l uni t an d steerin g
angl e sensor .
Wire sid e o f femal e terminal s
Repai r ope n in th e wir e betwee n
th e TC S contro l uni t an d steerin gangle sensor .
Erase th e DTC , an d tur n th e steer -
in g whee l slowl y afte r startin g
th e engine . I f TC S indicato r ligh t
come s o n an d DT C 2- 1 is indicated ,
replac e th e TC S contro l unit . TC
S CONTRO L UNI T 14 P CONNECTO R
ProCarManuals.com