1998 ACURA INTEGRA Service Repair Manual

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,I
Anti-lock Brake SYstem (ABS)
when the brake pedal is depressed during driving, the wheels can lock before the vehicle comes to a stop. In such an event.
the maneuverability of the vehicle is reduced if the front wheels are locked, and the stability of the vehicle is reduced if the
rear wheels are locked, creating an extremely unstable condition. The ABS precisely controls the slip rate o{ the wheels to
ensUre maximum grip force from the tires, and it thereby ensures maneuverbiIity and stabiIity of the vehicIe.
The ABS calculates the slip rate of the wheels based on the vehicle speed and the wheel speed. then it controls the brake
fluid oressure to attain the target slip rate
Features/Gonstructio n
Grip Foact ot Ti.c tnd Rotd Surfuco
COEFFICIEUT OFFNIG"TPN
Slip Rrtr
BRAKINGSTART POINT
i'l
A: f'3t rp withoul .lip
B: SIDp.d dirt.nc.G Actu.ldtt nc.io.top
sr.n arrr = f =
STOP POINTTARGET SUP RATE
SUP FATEVEHICT.C S'EEO - wlCEL SPEED
NO: Notm.lly oP.n
l{C: Noirnrly qo..d
19-26

IABS Control
The ABS control unit detects the wheel speed based on the wheel sensor signal it received, then it calculates the vehiclespeed based on the detected wheel speed. The control unit detects the vehicle speed during deceleration based on therate of deceleration.
The ABS control unit calculates the slip rate of each wheel, and it transmits the control signal to the modulator unitsolenoid valve when the slip rate is high.
The pressure reduction control has three-modes: pressure reduction, pressure retaining, and pressure intensifying.
Self-diagnosis Function
The CPUS in the ABS control unit check the circuit of the system.
The self-diagnosis can be classifield into two categories.. Initial diagnosis: Performed right after the engine starts and until the ABS indicator gose off.. Regular diagnosis: Performed right after the initial diagnosis until the ignition switch isturnedoff.
On-board Diagnosis Function
The ABS control unit is connected to the data link connector fi6p).The ABS system can be diagnosed with the Honda PGM Tester.
(cont'd)
19-27

Anti-lock Brake System (ABS)
Features/Construction (cont'd)
ABS Modulatol
The ABS modulator consists of the inlet solenoid valve, outlet solenoid valve, reservoir, pump, pump motor and the
damping chamber.
The modulator reduces the caliper fluid pressure directly. lt is a circulating-type modulator because the brake fiuid circulates
through the caliper, reservoir and the master cylinder.
The hydraulic control has three modes: pressure reduction, pressure retaining and pressure intensiiying
The hvdraulic circuit is the independent four channel-type, one channel tor each wheel'
L-__
RF LR
Pressure intensifying mode: Inlet valve open, outlet valve closed
Master cvlinder fluid is pumped out to the caliper.
Inlet valve closed, outlet valve closed
Caliper fluid is retained by the inlet valve and outlet valve.
lnlet valve closed, outlet valve open
Caliper fluid flows through the outlet valve to the reservolr'
When starting the pressure reduction mode, the pump motor is ON.
When stopping ABS operation, the pump motor is OFF.
The reservoir fluid is pumped out by the pump, through the damping chamber, to the master
cylinder.
\
Pressure retaining mode:
Pressure reduction mode:
Motor operation mode:
sott orD vALvE
@@-@@
TASIEF CYLI'OEF
19-24

Wheel Speed and Modulator Control
OUTLETVALVE oN
OFF
INLETVALVE ON
OFF
MOTOR
ON
OFF
When the wheel speed drops sharply below the vehicle speed, the inlet valve closes to retain the caliper fluid pressure.
When the wheel speed drops further, the outlet valve opens momentarily to reduce the caliper fluid pressure. The pump
motor starts at this time.
As the wheel speed is restored, the inlet valve opens momentarily to increase the caliper fluid pressure.
Wheel Sensor
The four wheel sensors are the magnetic contactless type. As the gear pulser teeth rotate past the wheel sensor's magnetic
coil, AC current is generated. The AC frequency changes in accordance with the wheel speed. The ABS control unit detects
the wheel sensor signalfrequency and thereby detects the wheel speed.
rr LOW SPEED
5
GEAR PUTSER
19-29

Gircuit Diagram
UIDES-HOOO FUSENELAY BOX
UNDER,HOOD ASSFUSSRELAY BOX CONN€CTORS4P CONNECTOR 3P CONNECTOR(O numb€r) (tr numb€r)
l./121./ 4l lrl2l3l
UNDER.DASHFUSFJRELAY BOX CONNECTORS18P CONNECTOR (O numb6r)
l235
I10121311a1,/67 t18
2op CONNECTOR (E number)
l356'78I
101l12/ 115t,/819
MAI(E S1IITCN06.d: 8.*! p.d.l @.!s.d
tGNtrotiSWITCH
p,-*@i
GAUGE ASSEMBLY CONNECTORS
16P CONNECTOR (O number)
SfMEL -
f,lBU -
Y&EtU -
*4
coiboz
EOWI-
BFAKE SWITCHCONNECTOR
fi
tr
FAIL,SAFE RELACONIiECTOR
Tr 121
M
A'ff.t#P;t"3.
ffi'
Jr:t r_E+?-|1]]
l.lXl. I tlL]jlJr:ly L-tr-J lLlAZ,)
PUMP MOTORCONNECTOF(tr numb€r)
,F.L?-]IJ
Tsrminal sids ol femalo tominals
5P CONNECTOR
f,rF-.Tt\
FUSE N0ftJSE UBEL IIAI,|E
15
t3P cONNEcToR (D numb€r)
19-30
Wke sido ol lomale l€rminels

SEFVCECfiEC{CONMCIOF (2P)
Ecgq f to'o..,I dinFD OITA LrNiLTILU i -- CoNr€CToF Lr6P)8LU!L'sru-6J;:--l
8AN/OJ( ltx
44c'li1 c2o]_crol
IIHEEI SENSOf,-------61',^r
,--Ej.*
ABS CONTROL UNIT22P CONNECTOR{O numbedWHEEL SENSONCONNECTOR
FRONTJEIL.rGT;-r\
REAR
lr 2l
SERVICE CHECKCONNECTOR (2P)
1t 1l
ABS CONTROL UNIT 12P CONNECTOR(l number)n t=l
lr 2 3l4ls 6l
lrl Bl;iiltilld
618910tl
t2'14161llt9202122
DATA LINK CONN€CTOR{16P)
121315
19-31
Wire sids ot lemale tsrminals

ABS Gontrol Unit Terminal Arrangement
ABS CONTROL UN]T 22P CONNECTOR
Wire side oI female t6rminals
Terminal
numbel
Wire
Golor
Terminsl sign
{Terminal
namet
Description
Measurgmgnt
TerminalConditions
{lgnition swhch ON {ll}}Voltage
1BLK/WHTGND3(Ground 3)
Ground1.GNDBelow 0.3 V
4GRN/REDPARK
{Parking)
Detects parking brake
switch signal4-GNDParking
brake
PulledBelow 0.3 V
Battery voltage
LT GRN/
BLK
FLW (-)
{FronLleft
wheel negative)
Detects left-front wheel
sensor srgnal
0.053 V or
above
0sci\oscope:
0.15 Vp-p or
above
7GBN/ORN
FLW (+)
(Front-left
wheel positive)- | Turn wheel at
E
1 turntsecona
l'GRN
FRW (-)
(Front-right
wheel negative)
Detects right-f ront wheel
sensor slgnal
8-9
1 FR\N (+)
I \GRN/BLK (Front-right
I I wheelpositiveStops0.25 - 1.15 V
10GRN/WHTSTOPDetects brake switch signal1O.GNDBrake pedalDepressedBaftery voltage
ReleasedBelow 0.3 V
11BLK/TELtG2
(lgnition 2)
Power source for activating
the system11-GNDlgnition
switch
oN {I)Battery voltage
Start (lll)Below 0.3 V
19-32

Terminal
numbel
Wire
color
Terminalsign
lTerminal
name,
Description
Measurement
T€rminalConditions(lgnition switch ON {ll}}Vohage
BLKMHTGND4(Ground 4)
G round12-GNDBelow 0.3 V
14BRN(Service
check signal)
Detects service check con-
nector signal (DTC indica-
tion or DTC erasure)
I4-GNDSCS short
connector
ConnectedBelow 0.3 V
DisconnectedApprox. 5 V
16BRNfYELMCK(Motor check)
Detects pump motor drive
srg nal16-GNDPump motorONBattery voltage
OFFBelow 0.3 V
17LT BLU
RLW (+)
{Rear-left
wheel positive)
Detects left-rear wheel sen-
sor signal
17-18
q,
3
Turn wheel at
l turn/second
AC:
0.053 V or
above
oscilloscope:
0.15 Vp-p or
aoove
18GRY
RLW (_)
(Rear-left
wheel negative)
19GRNIVEL
RRW (+)
(Rearright
wheel positive)
Detects right-rear wheel
sensor srgnal
19-20
20BLU//EL
RRW (-)
(Rear-right
wheel negative)Stops0.25 - 1.15 V
21YEUGRNFSR
{Fail-safe relay)
Drives failsafe relay
(Fail-safe relay is turned
OFF to shut off the power
source to the solenoid and
pump motor relay when
problem occurs.)
21-GNDABS indicator
ONBelow 0.3 V
OFFApprox. 11V
LT BLU
DLC(Data link
connectorl
Communicates with Honda
PGM Tester22-GND
19-33