1996 ACURA RL KA9 wheel

Troubleshooting Precautions

ABS Indicator

1. If the system is OK, the ABS indicator goes off 2 seconds after turning the ignition switch ON (II) without starting the

engine, and then comes on again and goes off after 2 seconds. This occurs because the ABS control unit is turned on

by the IG2 power source.

2. The ABS indicator comes on when the ABS control unit detects a problem in the system. However, even though the

system is operating properly, the ABS indicator will come on, under the following conditions.

Only drive wheels rotate

One drive wheel is stuck

Vehicle spin

ABS continues to operate for a long time

Signal disturbance

To determine the actual cause of problem, question the customer about the problem, taking these conditions into con-

sideration.

3. When a problem is detected and the ABS indicator comes on, there are cases when the indicator stays on until the igni-

tion switch is turned OFF, and cases when the indicator goes off automatically when the system returns to normal. For

DTCs 61 and 62, the indicator goes off automatically when the system returns to normal. For all other codes, the indica-

tor stays on until the ignition switch is turned OFF.

4. For DTCs 12, 14, 16, 18, 21, 22, 23, 24, 51, 52 and 53, the indicator goes off when the vehicle is driven again and the sys-

tem is OK after the ignition switch is turned from OFF to ON (II). However, if the DTC is erased, the CPU is reset and the

indicator goes off right after the engine is started if the system is OK.

Diagnostic Trouble Code (DTC)

1. If the CPU cannot be activated and the indicator comes on, the DTC is not memorized.

2. The memory can hold any number of DTCs. However, when the same DTC is detected more than once, the later one is

written over the old one. Therefore, when the same problem is detected repeatedly, it is memorized as 1 DTC.

3. The DTCs are indicated in the order of ascending number, not in the order they occur.

4. The DTCs are memorized in the EEPROM (non-volatile memory). Therefore, the memorized DTCs cannot be canceled

by disconnecting the battery. Perform the specified procedures to erase the DTCs.

Self-diagnosis

1. Self-diagnosis can be classified into 2 categories.

• Initial diagnosis: Performed right after the engine starts and until the ABS indicator goes off.

• Regular diagnosis: Performed right after the initial diagnosis until the ignition switch is turned OFF.

2. When a problem is detected by self-diagnosis, the system.

Turns the fail-safe relay OFF

Turns the solenoid valve OFF

Turns the pump motor OFF

Turns the ABS indicator ONProCarManuals.com

Troubleshooting Precautions

Kickback

1. The motor operates when the ABS is functioning, and the fluid in the reservoir is forced out to the master cylinder,

causing kickback at the brake pedal.

Pump Motor

1. The pump motor operates when the ABS is functioning.

2. The ABS control unit checks the pump motor operation during initial diagnosis when the vehicle is started. You may

hear the motor operate at this time, but it is normal.

Brake Fluid Replacement/Air Bleeding

1. Brake fluid replacement and air bleeding procedures are the same as vehicles without ABS. To ease bleeding, start

with the front wheels.

Troubleshooting

1. The troubleshooting flowcharts procedures assume that the cause of the problem is still present and the ABS indicator

is still on. Following the flowchart when the ABS indicator does not come on can result in incorrect diagnosis.

2. Question the customer about the conditions when the problem occurred, and try to reproduce the same conditions

for troubleshooting.

Find out when the ABS indicator came on, such as during initial diagnosis, during ABS control, after ABS control,

when vehicle speed was at a certain speed, etc.

3. When the ABS indicator does not come on during the test-drive, but troubleshooting is performed based on the DTC,

check for loose connectors, poor contact at the terminals, etc. before you start troubleshooting.

4. After troubleshooting, erase the DTC and test-drive the vehicle. Be sure the ABS indicator does not come on.

5. The connector illustrations show the female terminals with a single outline and the male terminals with a double outline.ProCarManuals.com

DTC 12 , 14 , 16 , 18 : Whee l Senso r (Electrica l Noise/Intermitten t Interruption )
Are the y installe d correctly ?
Chec k fo r a shor t t o wir e i n th e
on e whee l senso r circuit :
1 . Disconnec t th e AB S contro l
uni t 22 P connector .
2 . Measur e th e resistanc e
between th e appropriat ewheel senso r (+ ) an d (- ) cir -
cui t terminal s (se e table) .
I s ther e les s tha n 45 0 Q ?
Chec k fo r a shor t t o anothe r wir e
i n th e whee l senso r circuits :
Chec k fo r continuit y betwee n th e
appropriat e whee l senso r (+ ) cir -
cuit termina l an d othe r whee lsensor (+ ) circui t terminal s (se e
table) .
Is ther e continuity ? NOTE
: I f th e AB S indicato r come s o n fo r th e reason s describe d below , th e indicato r
shoul d g o of f whe n yo u test-driv e th e vehicl e a t speed s abov e 1 9 mp h (3 0 km/h) .
• Onl y th e driv e wheel s rotate d• Th e vehicl e spu n
• Electrica l nois e
DTC
12
1 4
16
18
Appropriat e Whee l Senso r
Right -fron t
Left - fron t
Right - rea r
Lef t - rea r
Reinstal l o r replac e th e appropri -
at e whee l senso r o r pulser .
DTC
12 (Right-front )
1 4 (Left-front )
1 6 (Right-rear )
1 8 (Left-rear )
Appropriat e Termina l
(+) Sid e
No. 9 : FR W (+ )
No . 7 : FL W (+ )
No . 19 : RR W (+ )
No . 17 : RL W (+ )
(-) Sid e
No. 8 : FR W (-)
No . 6 : FL W (-)
No . 20 : RR W <- )
No . 18 : RL W (-)
Repai r shor t t o wir e betwee n th e
appropriat e whee l senso r (+ ) an d
(- ) circuits .
DTC
12 (Right-front )
14 (Left-front )
16 (Right-rear )
18 (Left-rear )Appropriat
e
Termina l
No. 9 : FR W (+ )
No . 7 : FL W (+ )
No . 19 : RR W (+ )
No . 17 : RL W (+ )
Othe r Termina l
No. 7 : FL W (+ )
No . 9 : FR W (+ )
No . 9 : FR W (+ )
No . 9 : FR W (+ )
No . 19 : RR W (+ )
No . 19 : RR W (+ )
No . 7 : FL W (+ )
No . 7 : FL W (+ )
No . 17 : RL W (+ )
No . 17 : RL W (+ )
No . 17 : RL W (+ )
No . 19 : RR W (+ )
Repai r shor t t o wir e betwee n th e
appropriat e whee l senso r an d
th e othe r whee l sensor .
Wit
h th e ignitio n switc h O N
(II) , th e AB S indicato r doe s
not g o off .With th e SC S servic e connec -
to r connecte d (se e pag e
19-119 ), DTC s 12 , 14 , 16 , o r 1 8are indicated .
Visually chec k fo r appropriat ewheel senso r an d pulse r installa -
tio n (se e table) .
Eras e th e DT C an d test-driv e th e
vehicle . I f AB S indicato r conie s
o n an d sam e DT C is indicated ,
replac e th e AB S contro l unit .
ProCarManuals.com

Modulator Unit

Removal/Installation

NOTE:

Do not spill brake fluid on the vehicle; it may damage the paint; if brake fluid does not contact the paint, wash it off

immediately with water.

Take care not to damage or deform the brake lines during removal and installation.

To prevent the brake fluid from flowing, plug and cover the hose ends and joints with a shop towel or equivalent mate-

rial.

Removal

1. Disconnect the modulator unit and pump motor connectors.

2. Disconnect the brake lines, then remove the proportioning control valve.

3. Remove the modulator unit.

Installation

1. Install the modulator unit.

2. Install the proportioning control valve, then connect the brake lines. Tighten the flare nuts to 15 N-m (1.5 kgf-m, 11 Ibf-ft).

3. Connect the modulator unit and pump motor connectors.

4. Bleed the brake system, starting with the front wheels.

5. Start the engine, and check that the ABS indicator goes off.

6. Test-drive the vehicle, and check that the ABS indicator does not come on.

From

From left-front

right-front
MODULATOR UNIT

RUBBER MOUNT

MODULATOR UNIT

CONNECTOR

8 mm BOLT

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

BRACKET
PROPORTIONING

CONTROL VALVE

6 mm BOLT

9.8 N-m (1.0 kgf-m, 7.2 Ibf-ft)

PUMP MOTOR CONNECTOR

6 mm NUT

9.8 N-m (1.0 kgf-m, 7.2 Ibf-ft)ProCarManuals.com

Wheel Sensor Replacement

Install the sensors carefully to avoid twisting wires.

Front

6 mm BOLT

9.8 N-m (1.0 kgf-m, 7.2 Ibf-ft)

WHEEL SENSOR

Rear

6 mm BOLT

9.8 N-m (1.0 kgf-m, 7.2 Ibf-ft)

WHEEL SENSORProCarManuals.com

Component Locations

SERVICE CHECK CONNECTOR (2P)

ABS CONTROL UNIT

ECT SENSOR

TCS CONTROL VALVE

SENSOR

RIGHT-FRONT

WHEEL SENSOR

TCS CONTROL

VALVE ACTUATOR
LEFT-REAR

WHEEL SENSOR

GAUGE ASSEMBLY

ECU (PCM) (20 A) FUSE

UNDER-HOOD FUSE/RELAY BOX

BATTERY (120 A) FUSE
UNDER-HOOD RELAY BOX C

FAIL-SAFE RELAY

IG SW (50 A) FUSE

METER (15 A) FUSE
METER RELAY
TCS (15 A) FUSE
STOP/HORN

'96 - 98 models: (15 A) FUSE

'99 model: (20 A) FUSE
UNDER-HOOD FUSE/RELAY BOX
UNDER-HOOD RELAY BOX C

LEFT-FRONT WHEEL SENSOR
POWERTRAIN

CONTROL MODULE (PCM)
STEERING ANGLE SENSOR

RIGHT-REAR WHEEL SENSOR

TCS CONTROL UNIT

TCS/CRUISE SWITCH

UNDER-DASH FUSE/RELAY BOX

UNDER-DASH FUSE/RELAY BOX

METER (7.5 A) FUSE

TCS INDICATOR LIGHTProCarManuals.com

System Description

Outline

Role of System

The traction control is a variable system designed to enhance traction during acceleration and cornering. It does so by

determining the optimum amount of wheel spin for any given driving situation, then suppressing surplus engine power

accordingly.

Construction and Function

The TCS control unit gets signals about the vehicle's speed, direction, and road conditions from sensors at the wheels and

the steering column. Based on these signals, the control unit will determine the optimum amount of wheel spin. Because

the system is variable, the control unit may determine, depending on the driving conditions, that some wheel spin is bene-

ficial (thus enhancing straight-line acceleration), or that no wheel spin is beneficial (thus enhancing cornering). For any

given driving situation, the control unit will determine the amount of wheel spin best suited to the driver's needs and, if

necessary, will then signal the TCS control valve actuator and Powertrain Control Module (PCM) to reduce engine power.

The system is automatically "ready" whenever the engine is started, but can be manually canceled with the TCS switch.

However, once activated, the system cannot be canceled until it is once again in the ready state.

Components:

Wheel sensors: The TCS "shares" the wheel sensors with the ABS. The wheel sensors transmit wheel speed signals to

the TCS through the ABS control unit.

Steering angle sensor: The steering angle sensor signals the TCS control unit about the amount of steering angle.

TCS control valve sensor: The TCS control valve sensor signals the TCS control unit about the amount of TCS control

valve angle.

TCS control valve actuator: The actuator gets signals from the TCS control unit and closes the TCS control valve

accordingly.

TCS control unit: The TCS control unit detects the driving condition signals from the sensors and, if necessary, signals

the Powertrain Control Module (PCM).ProCarManuals.com

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.

Main Control BlockProCarManuals.com