2003 HONDA CIVIC ect

4. The blinking frequency indicates the DTC. DTCS are
indicated by a series of long and short blinks. One
long blink equals 10 shon blinks. Add the long and
short blinks together to determine the DTC. After
determining the DTC, refer to the DTC
Troubleshooting Index.
NOTE:. lf the DTC is not memorized, the ABS indicator
will go off for 3.6 seconds, and then come back
on.. lf the ABS indicatorstays on, troubleshootfor"ABS indicator does not go off" (see step 1 onpage 19-53).
Th€ system will not indicate the DTC unless these
conditions are met:. The brake pedal is not pressed.. The ignition switch is turned ON {ll).. The SCS circuit is shorted to body ground before
the ignition switch is turned ON (ll).
Example ot DTC 15
Long blinkShort blinks{five timesl
Examole of DTC 22
Long blinks (two times)
Turn the ignition swltch OFF,
Disconnect the Honda PG M Tester from the DLC.
5.
How to Clear ABS DTCs
Honda PGM Tester Method:
1. With the ignition switch OFF, connect the Honda
PGM Tester (A)to the l6Pdata link connector (DLC)
{B} under the driver's side of the dashboard.
Turn the ignition switch ON (ll), and clearthe
DTC(s) by following the screen prompts on the
PGM Tester.
NOTE: See the Honda PG l\4 Tester user's manual
for sDeclf ic instructions.
Cycling the lgnition Switch Method:
Clear the DTC by turning the ignition switch ON (ll) then
OFF at least 20 times.
19-33

ABS Gomponents
DTC Troubleshooting Index
DTCDetection ltemNote
DTC:11Rioht-front wheel sensor {ooen/short to bodv qround/short to power)(see oaoe 19-45)
DTC:12Faultv riqht-front wheel sensor oulse siqnal{see oaoe 19-46)
DTC:13Left-front wheel sensor {oDen/short to bodv qround/short to power)(see oaqe 19-45)
DTC:14Faultv left-front wheel sensor Dulse srqnal(see paqe 19-46)
DTC;15Riqht-rear wheel sensor (oDen/short to bodv qround/short to power)(see Daqe 19-45)
DTC:16Faultv riqht-rear wheel sensor oulse siqnal(see paqe 19-46)
DTC:17Left-rear wheel sensor (open/short to bodv qround/short to power)(see Daoe '19-45)
DTC:18Faultv left-rear wheel sensor Dulse siqnal(see Daqe '19-46)
Drc:2lContinuous oDeration (chioDed Dulser)(see paqe 19-47)
DTC:3'lSolenoid(see Daoe 19-48)
DTC:32Solenoid{see Daqe 19-48)
DTC:33Solenoid{see Daoe 19'48)
DTC:34Solenoidlsee oaqe 19-48)
DTC:35Solenoid(see paqe 19-48)
DTC;36So le no id(see Daqe 19-48)
DTC:37So le noid(see Daqe 19-48)
DTC:38Sole no id(see Daoe 19-48)
DTC:51lvlotor Iocked(see Daqe 19-48)
DTC:52lvlotor stuck off(see Daoe 19-49)
DTC:53lMotor stuck on(see Daoe 19-50)
DTC:54Main relav stuck off(see paqe 19-51
DTC:61lG2 voltaqe{see oaqe 19-5'l
DTC:81cPU (Central Processinq Unit){see paqe 19-52)
19-34

ABS Gomponents
System Description
ABS Control Unit Inputs and Outputs for 31P Connector
Wire side of temale terminals
124567BI11121415
16111B19
20?1/t/t/l/t/
Terminal
number
Wire
color
Terminal signDescriptionMeasurement
TerminalsConditions llgnition
switch ON (ll))Voltage
BLU/
YEL
RRSDetects righfrear
wneetsensor
srgnal
;a-_-l
6-7
Wheel
Spin wheelat
I turn/second
AC: 0.053 V or
above
Oscilloscope
0.15 Vp-p or
above
GRN/
YEL
RRS (+)
BLUFRS (-)Detects right-front
wneetsensor
srgnal
5GRN/
BLK
FRS (+)
6BRN/
WHT
FLS (_)Detects left-front
wneet sensor
srgnal7BLU/
ORN
FLS {+)
8GRY/
RED
RLS HDetects left-rear
wneetsensor
srgnal
89
9YEU
RED
RLS (+)
11LT BLUDIAG KCommunications
with Honda PGM
rester
12BRNDIAG LDTC indication
19-36

Terminal
number
Wire
color
TerminalsignDescriptionMeasurement
TerminalsConditions {lgnition
switch oN lll))
Voltage
14WHT/
BLK
STOPDetects brake
switch siqnal
I4-G NDBrake pedalPressedEattery
voltaoeReleased
t5BLV
ORN
rG2Power source for
activating the
svstem
15-GNDBaftery
voltage
16BLKM-GNDGround for the
0umD motor
16-GN DBelow 0.3 V
WHT/
RED
+ B-MRPower source for
the oumD motor
17-GNDAt alltimesBattery
voltaoe
18WHT/
GRN
+ B-FSRPower source for
the valve relav
,18-GNDAt alltimesBattery
voltaoe'19BLKGNDGround for the
modulator
assemDtv
19.GNDBelow 0.3 V
20B LU/
RED
ABSDrives ABS
indicator
20-GNDABS
indicator
ONAbout 11 V
OFFBelow 1 V
BRN/
YEL
EBD(Electronic brake
distribution)
Drives brake
system indicator
21-GNDBrake system
indicator
OFFBelow 0.3 V
ON for
bulb
cnecK
8attery
voltage
(cont'd )
19-37

ABS Control Unit
Main Control
The ABS control unit detects the wheel speed based on the wheel sensor signal it received, then it calculates the
vehicle speed based on the detected wheel speed. The control unit detects the vehicle speed during deceleration
based on the rate of deceleration.
The ABS control unit calculates the slip rate of each wheel and transmits the control signal to the modulator unit
solenoid valve when the slip rate is high.
The pressure reduction control has three modes: pressure reducing, pressure retaining, and pressure intensifying.
Self-diagnosis Function
1. TheABScontrol unitisequippedwithamainCPUandasub-CPU.EachCPUcheckstheotherforproblems.
2. The CPUS check the circuit of the system.
3. TheABScontrol unitturns ontheABS ind icator when the unitdetectsa problem andthe unit stops th e system.
4. The self-diagnosis can be classified into these two categories:. lnitial diagnosis. Regular diagnosis
On-board Diagnosis Function
The ABS can be diagnosed with the Honda PGM Tester.
The ALB Checker cannot be used with this system. For air bleeding and checking wheel sensor signals. use the Honda
PGM Tester. See the Honda PGM Tester user's manual for specific operating instructions.
(cont'd)
T---
19-39

ABS Components
System Description (cont'd)
ABS Modulator
The ABS modulator consists of the inlet solenoid valves, outlet solenoid valves, reservoir, pump, pump motor, and the
damping chamber. The modulator reduces the caliper fluid pressure directly. lt is a circulating-type modulator
becausethe brakefluidcirculatesthroughthecaliper,reservoir,andthemastercylinder.Thehydrauliccontrol has
three modes: pressure intensifying, pressure retaining, and pressure reducing. The hydraulic circuit is an independent
four-channeltype, one channel for each wheel.
Pressure intensifying mode: Inletvalve open, outlel valve closed
Master cylinder fluid is pumped out to the caliper.
Pressure retaining mode: lnlet valve closed, outlet valve closed
Caliper fluid is retained by the inlet valve and outlet valve.
Pressure reducing mode: Inlet valve closed, outlet valve open
Caliper fluid flows through the outlet valve to the reservoir.
lvlotor operation mode: When starting the pressure reducing mode, the pump motor is ON.
When stopping ABS operation, the pump motor is OFF.
The caliper fluid is pumped out by the pump, through the damping chamber, to the
master cvlinder.
19-40

t
Wheel Sensors
The 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 signal frequency and thereby detects the wheel speed.
!t LOW SPEED
Wheel Speed and Modulator Control
8E!EEETqE VEJ!q!ESPEEq
5
PRESSURE
OUTLETVALVE 9p
OFF
INLETVALVE oN
OFF
MoroR I-,. ltlOFF
When the wheel speed drops sharply below the vehicle speed, the inlet valve closes and il necessary, the outlet valve
opens momentarily to reduce the caliper fluid pressure. The pump motor starts at this time. As the wheel speed is
restored, and the outlet valve closes, the inlet valve opens momentarily to increase the caliper fluid pressure.
GEAR PULSERWHEEL S€NSOR.r HIGX SPEED
19-41

ABS Components
q,
CONNECTOR A {12P)BRAKE PEDAL POSITIONSWITCH 4P CONNECTOR
Circuit Diagram (cont'd)
UNDER-HOOD FUSE/RELAY BOX CONNECTORSCONNECTOR A {12P) CONNECTOR B {2P}
UNDER.DASH FUSE/RELAY BOX CONNECTORSCONNECTOR I {5P)CONNECTOR K I17P)MULTIPLEX CONTROLUNIT 13P CONNECTOR
CONNECTOR B I22PI
1l2l3l,/15
GAUGE ASSEMBLY CONNECTORS
CONNECTOR A I22P)
WHEEL SENSOR 2P CONNECTORS
FRONT
J --T:-l Ltqtt/)l'l L_.:-:J r\-r-----Tr'e:l
RIGHT.REAR LEFT-REAR
tslTt?t /J 1T-1\I tL | rlziJ
Terminal side of male lerminals
ABS CONTROL UNIT 3IP CONNECTOR
OATA LINK CONNECTOR {16P)
Terminal side of female terminals
Wire side of female terminals
1234567
810111213141511
123,/ ,/
67891011n213
1245678I11121415
161118192021/1,/1,/vl,/l
/t,/t/t,/t/
19-44