sensor HONDA CIVIC 2002 7.G Workshop Manual

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

ABS Components
DTC Troubleshooting (cont'dl
7. Check the resistance between the appropriate
wheel sensor (+) and ( ) circuit terminals {seeta ble).
DTCAppropriate Terminal
l+) Side*lSide
11 {Riqht-front)No.5: FRS (*)No.4:FRS 1-)'13 {Left-front)No. 7: FLS {+iNo.6: FLS (-
15 (Rioht-rear)No. 2: RBS {+)No. 1:RBS (-)
17 (Left-rear)No.9: RLS 1-No.8: BLS (-
ABS CONTROL UNIT 31P CONNECTOR
Wire side of female terminals
Is the rcsistance between 450 2,000 A ?
YES Check for a loose ABS control unit3lP
connector. lf necessary. substitute a known-good
ABS modulator-control unit, and recheck.l
NO Go to step 8.
Disconnect the harness 2P connector from theappropriate wheel sensor, and check the resistance
between the (+) and { )terminalsof thewheel
sensor.
ls the resistance between 450- 2,000 Q ?
YES-Repair open in the (+) or (-) circuit wire, orshort between the (+) circuit wire and the { )circuit wire between the ABS modulator-control
unit and the wheel sensor.l
NO Replace the wheel sensor.l
19-46
DTC12,14, 16, 18: Wheel Sensor Putse
Signal
NOTE: lf the ABS indicator comes on for the reasonsdescribed below, the indicator goes off when you test-drive the vehicle at 31 mph (50 km/nl.
. Only the drive wheel rotated. The vehicle spun. Electrical noise
1. Visually check for appropriate wheel sensorandpulser installation and condition (see table).
DTCAppropriate Wheel Sensor
12Riqht-front
14Left-front
Riqht-rear
18Left-rear
Ate they installed correctly and not damaged?
YES-Go to step 2,
NO Reinstall or replace the appropriate wheelsensor or pulser,I
Disconnect the ABS control unit 31P connector.
Measure the resistance between the appropriate
wheel sensor ( f) and ( ) circuit terminals (see
table).
ls therc less than 450 Q ?
YES Go to step 1.
NO-Go to step 4.
\\|D
2.
3.
DTCAppropriate Terminal
l*) Side) Side
12 {Rioht-front)No.5:FBS (*No.4:FBS
14 (Left-front)No.7;FLS l*No,6:FLS
16 (Riqht.rear)No.2: RRS (*No. 1:BRS
18 (Left-readNo.9: BLS 1-No.8:RLS

4. Check for continuity between the appropriate
wheel sensor (+) circuittermlnal and otherwheel
sensor (+) circuit terminals (see table).
DTCAppropiate
Terminal
Other Terminal
12No.5:
FRW (*i
No.7No.2No.9
'14No.7:
FLW IT.)
No.5No.2No.9
toNo.2;
RRW (T-)
No.5No.7No.9
18No.9:
RLW (*)No.5No. 7No.2
ls there continuity?
YES Repair short in the wires between the
appropriate wheel sensor and the other wheel
sensor harnesses.l
NO Clear the DTC, disconnect the Honda PGM
Tester, and test-drive the vehicle. lf the ABS
indicator comes on and the same DTC is indicated,
replace the ABS modulator-control unit.l
Disconnect the harness 2P connector from the
appropriate wheel sensor and check the resistance
between the (+) side and the (-) side ofthe wheel
sensor.
ls there less than 450 Q ?
YES Replace the wheel sensor.
NO- Repair short to wire between the appropriate
wheel sensor (+) and (-)circuits.l
DTC 21: Continuous Operation (Chipped
pulser)
1. Clear the DTC, then disconnect the Honda PGM
tesler.
2. Test-drive the vehicle at 19 mph (30 km/h) or more.
Doesthe ABS indicator come on and is DTC 21
ind icated?
YES Go to step 3.
NO The system is OK at this time.l
3. Check the pulser gear for a chipped tooth.
ls the pulser OK?
YES Check for a loose ABS control unit 31P
connector. lf necessary, substitute a known-good
ABS modulator-control unit, and recheck.l
NO Replace the driveshaft or hub unit (chipped
pulser gear).1
1g-47

Wheel Sensor Inspection
1.
2.
Inspect the front and rear pulsers for chipped or
damaged teeth.
Measure the air gap between the wheel sensor and
the pulser all the way around while rotating the
pulser. Remove the rear brake disc to measure the
gap on the rear wheel sensor. lf the gap exceeds
1.0 mm (0.04 in.), check for a bent suspension arm.
Standard:
Front; 0.4- 1.0 mm (0.02-0.04 in.)
Rear: 0.2 1.0 mm (0.01 0.04 in.l
Front:
0.4 '1.0 mm10.02 0.0'l in.l
I
t
Bear:
0.2 1.0 mm{0.01 0.04 in.}
Wheel Sensor Replacement
NOTE: Inslall the sensors carefully to avoid twisting the
wtres.
Front:
6 mm BOLT9.8 N.m{1.0 kgf.m,7.2lbf.ftl
6 mm BOLT9.8 N.m{1.0 kgf.m,7.2 lbf.ftl
Rear:
6 mm BOLT9.8 N.m11.0 kgf.m,7.2 lbf.ft)
WHEEL SENSOR
6 mm BOLT9.8 N.m(1.0 kgf'm,7.2 rbr.ft)
19-59

Front Seat Cover Replacement
For some models: SRS components are located in this
area. Review the SRS component locations (see page
23 13) and the precautions and procedures (see page
23-'14) in the SRS section before performing repairs or
service,
NOTE:. Take care not to tear the seams or damage the seat
covers,. On the passenger's seat with side airbag, do not
touch the OPDS sensor in the seat-back pad, and keep
it away from oil. Oil can corrode the sensor causing it
to fail.. Put on gloves to protect your hands.
Seat-back Cover
Remove the front seat isee page 20-71).
With side airbag: From under the seat cushion,
detach the side airbag connector clip (A), and on
the passenger's seat, detach the OPDS unit
connector clip (B). Release the hook springs (C)
from the seat cushion frame spring {D), then pull
the guide cover (E) back, and remove the wire ties
(F). The passenger's seat is shown, the driver's seat
is svmmetrical except it has no OPDS unit
connector.
'L
2.
3.Fold the seat-back forward.
Release the hooks (A), and unzip the seat-back
cover (B).4.
(cont'd)
20-75

21-2
z t-'5
z t-o
z t-o
21-8
21-9
21-10
21-11
21-14
z t- to
HVAC (Heating, Ventilation, and Air Gonditioningl
Heating and Air Conditioning
SpecialTools
Comoonent Location lndex ........
A/C Service Tios and
Precautions
A,/C Refrigerant Oil
ReDlacement
General Troubleshooting
lnformation
DTC Troubleshooting Index .......
Symptom Troubleshooting
1ndex..............
System Description .....................
Circuit Diagram
DTC Troubleshooting ..................
Recirculation Control Motor
CircuitTroubleshooting .......... 21-25
Heater Control Power and Ground
Circuits Troubleshooting ........ 21-27
Condenser Fan Circuit
Troubleshooting ...................... 21-28
Radiator and Condenser Fans
Common Circuit
Troubfeshooting ...................... 21-29
Compressor Clutch Circuit
Troubleshooting ...................... 21-30
A,/C Pressure Switch Circuit
Troubleshooting ...................... 21-32
Air Mix Control Motor
Test and Reolacement ............. 21-34
Mode Control Motor
Test and Replacement ............. 21-35
Recirculation Control Motor
Test and Reolacement ............. 21-36
Evaporator Temperature Sensor
Reolacement and Test ............. 21-31
Power Transistor Test ................. 21 -38
Heater Control Panel and
Push Switch Assemblv
Removal and Installation ........ 21-38
Dust and Pollen Filter
Reolacement ..21-39
Blower Unit Removal and
lnstallation ...... 21-39
Blower Unit Comoonents
ReDlacement ............................ 21-41
Evaporator Core
Reolacement ..21-42*Heater Unit/Core
ReDlacement ..21-43
Heater Valve Cable
Adjustment .....21-46
CompressorReplacement .......... 21-47
Comoressor Clutch Check .......... 21-48
Comoressor Clutch Overhaul ..... 21-49
Compressor Thermal Protector
Reo1acement ............................ 21-51
Comoressor Relief Valve
Reolacement ............................ 21-51
Condenser Reolacement ............ 21-52
Refrigerant Recovery .................. 21-53
System Evacuation ...................... 21-54
System CharginS ......................... 21-55
Refrigerant LeakTest .................. 21-56
A,/C Svstem Tests ........................ 21-57