ECT sensor HONDA CIVIC 2003 7.G Workshop Manual

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

DTC Troubleshooting Index
In case of multiple problems, the recirculation indicator will indicate only the DTC with the least number of blinks.
ln case of an intermittent failure, the heater control panel will store the DTC until the ignition is turned off.
DTC {Recirculation
Indication Blinks)
Detection ltemPage
7An open in the air mix control motor circuit(see paqe 21-16)
8A short ln the air mix control motor circuit(see Daoe 21-'16)
9A problem in the air mix control linkaqe, door, or motor(see paqe 21- 17)
10An open or shon in the mode control motor circuit(see oaqe 21-18)
11A problem in the mode control linkage, doors, or motor(see paqe 21191
12A problem in the blower motor circuit(see paqe 21-20)
13A problem in the EEPROM in the heater control panel;
the control oanel must be reolaced
(see page 21-38)
14An ooen in the evaDorator temDerature sensor circuit(see paqe 21-23)
A short in the evaDoralor temoerature sensor circuit(see oaqe 21-241
21-9

System Description
Heater Control Panel Inputs and Outputs
CONNECTOR A {r/rP)
CONNECTOR
CONNECTOR
HEATER CONTFOL PANEL CONNECIORS
CONNECTOR B (22P)
W re s de oitema eterm nals
Cavity Wire color_| \ln YAIR MIX POTENTIAL +5V
Sional
OUTPUT2LT GRNSENSOR COMMON GROUNDINPUT3PNK/BLUAIR MIX HOTOUTPUTBLUA,/C PRESSURE SWITCHINPUT5GRNA/ELRECIRCULATEINPUT6GRNA/VHTFRESHINPUT7BLUI/ELPOWER TRANSISTOROUTPUT8BLU/REDBLOWER FEEDBACKINPUTIGRNAIR MIX COOLOUTPUT10YEL/REDMODE DEFOUTPUT11. YEVBTU
YEL/BLK
MODE VENT
REAR WINDOW DEFOGGER RELAY
OUTPUT
INPUTBLKGROUNDOUTPUT14B LK/YELlG2 (Power)INPUT
Bon
CavityWire colorSiqnal1--T
2
3BLIVREDREAR WINDOW DEFOGGER SWITCH LEDINPUT
4LT GRNA./C SWITCH LEDINPUT
5LT GRN/BLKRECIRCULATION CONTROL SWITCH LEDINPUT
6PNVBLKAIR MIX POTENTIALOUTPUT
7BRNEVAPORATOR TEIMPERATURE SENSOROUTPUT
8
9
10
GAUGE ASSEMBLYal' 'TDr ri11RED
RED/BLKTAILLIGHTS RELAYINPUT
14BLUREAR WINDOW DEFOGGER SWITCHINPUTicLT GRN/REDA/C SWITCHINPUT16YEVREDRECIRCULATION CONTROL SWITCHINPUT17YEUGRNMODE 4OUTPUT18WHT/BLUMODE 3OUTPUT19RED/BLUMODE 2OUTPUT20RED/YELMODE 1OUTPUTBRN^,^/HTIGN (PowedOUTPUT22R E DA/r'HT(Not used)
(cont'd)
21-11

Heating and Air Gonditioning
System Description (cont'dl
The air conditioning system removes heat from the passenger compartment by circulating refrigerant through the
system as shown below.
/
BLOWER FAN
\
\,u
EXPANSION VALVE(Meters the requiredamount of refrigerantinto the evaporator)
A/C PRESSURE SWITCHWhen the refriqerant is below196 kPa (2.0 kgi/cm',28 psi)or above 3,140 kPa (32 kgf/cm'455 psi), the Py'c pressureswitch opens the circuit tothe Py'C switch and stops theair conditioning to protect thecompressor-
RECEIVER/DRYER(Traps debris, andremoves morsturel
APOBATOR TEMPERATURESENSOR
THERMAL PROTECTOR(Opens the compressor clutch circuitwhen the compressot temperaturebecomes too high)
RELIEF VALVE(Relieves pressure at the compressorwhen the pressure is too high)
A/C COMPRESSOR(Suction and comoression)\-^
I HrcH PRESSURE vAPoR
[ '.... -:--l Low PREsSUBE LrourD
tffi Low PREssURE vAPoR
This vehicle uses HFC-134a (R-'134a) refrigerant which does not contain ch lorofluorocarbons. Pay attention to the
following service items:
. Do not mix refrigerants CFC-12 (R-12) and HFC-134a (R-134a). They are notcompatible.. Use onlythe recommended polyalkyleneglycol (PAG ) refrigera nt oil (KElHlN SP '!0) designedfortheR-134a
compressor. Intermixing the recommended (PAG) refrigerant oil with any other retrigerant oil will result in
compressor failu re.. AllAy'C system parts (compressor, discharge line, suction line, evaporator, condenser, receiver/dryer. expansion
valve, O-rings for joints) have to be designed for refrigerant R 134a. Do not exchange with R-'12 parts.
. Use a halogen gas leak detector designed for refrigerant R-134a.. R-12 and R-134a refrigerant servicing equipment are not interchangeable. Use only a recovery/recycling/charging
station that is U.L.-listed and is certified to meet the requirements of SAE J2210 to service R-134a air conditioning
system.. Always recover the refrigerant R-134a with an approved recovery/recycling/charging station before disconnecting
any Ay'C fifting.
/-
CONDENSER(Radiation of heat)
21-12

DTC 14: An Open in the Evaporator
Temperature Sensor Circuit
1. Remove the evaporator temperature sensor (see
page 21-37).
2. Measure the resistance between the No. l and
No. 2 terminals of the evaporator temperature
sensor.x Dip the sensor in ice water, and measure
resistance. Then pour hot water on the sensor, and
check for change in resistance.
EVAPORA
RESISTANCEk0
TOR TEMPERATURE SENSOR
t-lll#l
ll,l,llI UT-TU I---r---T--
t^11c))-l\9/
50 6810 20
TEMPERATURE
ls the tesistance within the specifications shown
on the graph?
YES-Go to step 3.
NO Replace the evaporator temperature
sensor.I
3. Disconnect heater control panel connector B {22P).
86'F30 'c
Terminal side of male terminals
4. Check for continuity between the No. 7 terminal of
heater control panel connector B (22P) and the
No. 1 terminal of the evaporalor temperature
sensor 2P connector.
HEATER CONTROL PANEL CONNECTOR B {22P)Wire side of female terminals
EVAPORATOR TEMPERATURE SENSOR 2P CONNECTORWire side of female terminals
ls there continuity?
YES Go to step 5.
NO Repair open in the wire between the heater
control panel and the evaporator temperature
sensor.I
5. Disconnect heater control panel connector A (14P).
(cont'd)
21-23

Heating and Air Gonditioning
\
DTC Troubleshooting {cont'd)
6. Check for continuity between the No. 2 terminal of
heater control panel connector A (14P) and the
No, 2 terminal of the evaporalor temperature
sensor 2P connector.
HEATER CONTROL PANEL CONNECTOR A {14PIWire side of female terminals
LT GRN
EVAFORATOR TEMPERATURE SENSOR 2P CONNECTORWire side of female terminals
ls there continuity?
YES-Check for loose wires or Door connections at
heater control panel connector A ('l4P) and B l22Pl
and at the evaporator temperature sensor 2P
connector. lf the connections are good, substitute a
known-good heater control panel, and recheck. lf
the symptom/indication goes away, replace the
original heater control panel.l
NO Reoair ooen in the wire between the heater
control panel and the evaporator temperature
sensor.I
21-24
4.
DTC 15: A Short in the Evaporator
Temperature Sensor Circuit
1. Remove the evaporator temperature sensor (see
page 21-37).
2. Test the evaporator temperature sensor (see page
21-37 J.
ls the resistance within the specifications shown
on the graph?
YES Go to step 3.
NO Replace the evaporator temperature
sensor. !
Disconnect heater control panel connector B l22Pl.
Check for continuity between the No. 7 terminal of
heater control panel connector B {22P) and body
ground.
HEATER CONTROL PANEL CONNECTOR B (22P)
Wire side of female terminals
ls there continuity?
YES Repair short to body ground in the wire
betvveen the heater control panel and the
evaporator temperature sensor. I
NO-Substitute a known-good heater control panel,
and recheck. lf the symptom/indication goes away,
replace the original heater control panel.I