ECT sensor HONDA CIVIC 2003 7.G Workshop Manual

Rear Suspension
Hub Bearing Unit Replacement
(cont'd)
9. Remove the hub bearing unit (A) from the spindle.
Install the hub bearing unit in the reverse order of
removal, and note these items:
. Tighten all mounting hardware to the specified
torque values,. Before installing the brake disc, clean the mating
surface ot the hub and the inside of the brake
disc.. Use a new spindle nut on reassembly.. After tightening, use a drift to stake the spindle
nut shoulder against the spindle.. Use a new hub cap on reassembly.. Before installing the wheel, clean the mating
surface of the brake disc and the inside of the
wneel.
10.
,=,,,
18-28
Raise the rear of the vehicle, and suppon it with
safety stands in the proper location (see page 1-8).
Remove the rear wheels.
Remove the brake disc and hub bearing unit (see
step 1 on page 18-27).
Remove the flange bolts (A) and splash guard (B)
from the knuckle.
11.0 kgf.m, 7.2 lbf ft)
4. Remove the wheel sensor(A), braKe nose
mounting bracket (B), and parking cable mounting
bracket (C) from the knuckle. Do not disconnect the
wheel sensor connector.
8 x 1.25 mm22 N.m{2.2 kgf m, 16 lbf ftl
Knuckle Replacement
1.
6x1.0mm9.8 N,m{I.0 kgt.m,7.2 lbf ft)
tt

Master Cylinder Replacement
NOTE: Do not spill brake fluid on the vehicle; it may
damage the paint; if brake fluid does contact the paint,
wash it off immediately with water,
1, Remove the air cleaner assembly (A).
2, Disconnect the brake fluid level sensor connector
(A).
15 N.m{1.5 kgt.m, 11 lbt.ft)
3. Remove the clutch reservoir (B) andenginewire
harness clip (C)from the master cylinder mounting
base (D).
4. Remove the reservoir cap and brake fuid from the
reservoir.
5. Remove the reservoir (E) on the master cylinder
mountrng Dase.
6, Disconnect the brake lines (F)from the master
cylinder (G). To prevent spills, cover the hose joints
with rags or shop towels.
7. Remove the master cylinder mounting nuts {H) and
washers.
8. Remove the master cylinder from the brake booster.
Be careful not to bend or damage the brake lines
when removing the master cylinder.
9. Remove the rod seal (l) from the master cylinder.
10. Installthe master cylinder in the reverse order of
removal, and note these items:
. Replace all the rubber parts with new ones
whenever the master cylinder is removed.
. Check the pushrod clearance before installing the
master cylinder. and adjust it if necessary (see
page 19-16).. Use a new rod seal on reassemblY. Coat the inner bore lip and outer circumference
of the new rod seal {A) with the recommended
seal grease in the master cylinder set.
. Installthe rod seal ontothe master cylinder with
its grooved side (B)toward the master cylinder.
. Check the brake pedal height and free play after
installing the master cylinder, and adjust it if
necessary (see page 19-6).
19-15

Brakes
Conventional Brake Components ................ 1 9-1
ABS (Anti-lock Brake System) Components
Comoonent Location lndex .............,........................... 19-30
General Troubleshooting Information ....................... 19-31
DTC Troubleshooting Index .............. 19-34
Symptom Troubleshooting Index ...,........................... 19-35
System Description ................. ........... 19-36
Circuit Diagram ......... 19-42
DTC Troubleshooting ............... .......... 19-45
ABS Indicator CircuitTroubleshooting ...................... 19-52
Brake System Indicator Circuit
Troubleshooting ...................... ....... 19-55
ABS Modulator-Control Unit Removal and
lnstallation ............. 19-57
Wheel Sensor Insoection ................... 19-59
Wheel Sensor Reolacement .............. 19-59

ABS Gomponents
(Component Location Index
UNDER.HOOD FUSE/RELAY BOX
RIGHT-REAR WHEEL SENSORInspection, page 19-59Replacement, page 19-59UNDER.OASH FUSE/RELAY BOX
\L
LEFT.REARWHEEL SENSORInspection, page 19-59Replacement, page 19-59
DATA LINK CONNECTOR I16PIRIGHT.FRONT WHEEL SENSORInspection, page 19-59Replacement, page 19-59
ABS MODULATOR.CONTROL UNITRemoval and Installation, page 19'57LEFT-FRONT WHEEL SENSORInspection, page 19-59Replacement, page 19 59
19-30

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

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

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

\
DTC Troubleshooting
DTC 11, 13, 15, 17: Wheel Sensor
(Open/Short to Body Ground/Short to Power)
1. Disconnect the ABS control unit 31P connector.
2. Sta rt the engine.
3. Measure the voltage between the appropriate
wheel sensor (*)circuitterminal of theABS
control unit 31P connector and body ground (see
table).
DTCADpropriate Terminal
11 (Rioht-front)No.5: FRS (t)
13 (Left-front)No, 7: FLS (*)
15 {Riqht-rear}No. 2: RRS (*)
17 (Left-rear)No.9 RtS (f )
ABS CONTROL UNIT 31P CONNECTOR
FRS {+IIGNR/BLK} FLS I+I (BLU
RRS {+)(GNR/YEL)
Wire side of female terminals
ls thete battery voltage?
YES Repair short to power in the (+) circuit wire
between the ABS modulator-control unit and the
appropriate wheel sensor. I
NO Go to step 4.
4. Turn the ignition switch OFF.
5. Check for continuity between the appropriate
wheel sensor (+ ) circuit terminal and body ground
{see table).
DTCAppropriate Terminal
11 (Riqht-front)No. 5: FRS (+)
13 (Left-front)No. 7: FLS (*)
15 (Rioht-rear)No.2: RRS (*)
17 (Left-rear)No.9 RLS (+l
ABS CONTROL UNIT 31P CONNECTOR
Wire side
ls there continuity?
YES Go to step 6.
NO-Go to step 7.
Disconnect the harness 2P connector from the
appropriate wheel sensor, then check for continuity
between the 1+)and ( )terminals ofthe harness
and body ground.
ls there continuity?
YES-Repair shortto body ground in the (+)or { )
circuit wire between the ABS modulator-control
unit and the wheel sensor.l
NO Repiace the wheel sensor.l
(cont'd)
Wire side of female terminals
19-45