2003 HONDA CIVIC Circuit

9.
10.
Disconnect the condenser fan 2P connector,
Check for continuity between the No. 1 terminal of
the condenser fan relay 4P socket and the No. 2
terminal of the condenser fan 2P connector.
CONDENSER FAN RELAY 4P SOCKET
CONDENSER FAN 2P CONNECTORWire side of female terminals
Is there continuity?
YES Go to step 1 1.
NO- Repair open in the wire between the
condenser fan relay and the condenser fan,I
Check for continuity between the No. 1 terminal of
the condenser fan 2P connector and body ground.
CONDENSER FAN 2P CONNECTOR
12
BLK
o
Wire side of {emale terminals
ls there continuity?
YES- Replace the condenser fan motor.I
NO Check for an open in the wire between the
condenser fan and body ground. lf the wire is oK,
check for poor ground at G301.1
'11 .
Radiator and Condenser Fans
Common Circuit Troubleshooting
NOTE; lf both fans and the Ay'C compressor clutch do
not work when the Ay'C switch is on, go to Ay'C Pressure
Switch Circuit Troubleshooting (see page 21-32l, .
1. Check the No. 1 {20A} and No. 4 (20A) fuses in the
under-hood fuse/relay box, and the No. 14 (10A)
fuse in the under-dash fuse/relay box.
Are the tuses OK?
YES Go to steD 2.
NO Replace the fuse(s), and recheck.l
2. Remove the condenser fan relav from the
under-hood f use/relay box.
3. Turn the ignition switch ON (ll;.
4. Measure the voltage between the No. 3 terminal of
the condenser fan relay 4P socket and body ground.
ls there battery voltage?
YES Go to step 5.
NO Repair open in the wire between the No. 14
fuse in the under-dash fuse/relay box and the
radiator fan relay, and the condenser fan relay.l
5. Turn the ignition switch OFF.
6. Reinstall the condenser fan relay.
7. Make sure the IVC switch is OFF.
8. Turn the ignition switch ON (ll).
(cont'd)
CONDENSER FAN RELAY 4P SOCKET
r-,
-l
12lf---r---
l,l,l
lar-vver-
l
o
I
21-29

Heating and Air Conditioning
Radiator and Condenser Fans
Common
(cont'dl
Circuit Troubleshooting
9. Using a Backprobe Set, measure the voltage
between the No. 6 terminal of ECN4 connector B
{24P) and body ground with the ECM connectors
connecteo.
ECM CONNECTOR B {24P}
ls there battery voltage?
YES UDdate the ECM if it does not have the latest
so{tware, or substitute a known-good ECM, then
recheck (see page 11-6). lf the symptom/indication
goes away with a known-good ECM, replace the
original ECM.I
NO Repair open in the wire between the radiator
fan relay, the condenser fan relay and the ECM. t
Wire side of female terminals
21-30
Compressor Clutch Circuit
Troubleshooting
1. Check the No. 1 (20A) fuse in the under-hood
fuse/relay box, and the No. 14 {10A)fuse in the
under-dash fuse/relay box.
Are the tuses OK?
YES Go to step 2.
NO Replace the fuse(s), and recheck.I
2. Check the engine coolant temperature, the throttleposition sensor, and the idle speed (use the Honda
PGM Tester PGM-Fl data list if possible).
ls the coolant temperaturc above nomal, the
throttle position sensor rcading too high, or the
idle speed too low?
YES Troubleshoot and repair the cause of the
high engine coolant temperature, high throttle
position sensor reading, or low idle speed.l
NO-Go to step 3.
3. Remove the compressor clutch relay from the
under-hood fuse/relay box, and test it (see page 22-
51 ).
ls the relay OK?
YES Go to step 4.
NO Replace the compressor clutch relay.I
4. Measure the voltage between the No. 2 terminal of
the compressor clutch relay 4P socket and body
ground.
\
COMPfiESSON CLUTCH BELAY 'P SOCKET
ls there battery voltage?
YES Go to step 5.
NO Replace the under-hood fuse/relay box.I

Heating and Air Conditioning
Compressor Clutch Circuit
Troubleshooting (cont'dl
16. Check for continuity between the No. lterminal of
the compressor clutch relav 4P socket and the No. l
terminal of the compressor clutch 1P conneclor.
COMPRESSON CLUTCH RELAY 4P SOCKET
COMPRESSOR CLUTCH 1P CONNECTORTerminal side of male terminals
ls therc continuity?
YES-Check the compressor clutch clearance, the
thermal protector, and the compressor clutch field
coil (see page 21-48).I
NO-Repair open in the wire between the
compressor clutch relay and the compressor
clutch.l
21-32
A/C Pressure Switch Circuit
Troubleshooting
'1. Turn the ignition switch ON {ll).
2. Turn the blower switch on, and check for blower
motor operatron.
Does the blower motor run on all speeds?
YES Go to step 3.
NO Troubleshoot the blower motor circuit (see
page 21-20).
3. Turn the ignition switch OFF.
4. Disconnect heater control panel connectorA ('14P).
5. Turn the ignition switch ON (ll).
6. Measure the voltage between the No, 4 terminal of
heater control panel connector A {14P) and body
grou nd.
HEATER CONTROL PANEL CONNECTOR A (I4P}
1.
ls there battety voltage?
YES Go to step 7.
NO-Go to step 9.
Stan the engine.
Wire side of female termina's

\Body Electrical
Body ElectricalSpecialToolsGeneral Troubleshooting tntorrnaiion.'......
Relay and Control Unit Locations .....
Connectors and Harnesses
Fuse/Relay Boxes ...............................
Power Distribution .............................
Ground Distribution ...........................
Under-dash Fuse/Relay Box ..............
Battery ..............
Relays ................
*lgnition Switch ..............
*Gauges
Component Location Index .......................Self-diagnostic Procedure ..........................Circuit DiagramGauge Bulb Replacement ..........................Gauge Assembly ReplacementCoolant Temperature
Gauge Troubleshooting .... ....................Vehicle Speed Signal CircuitTroubleshootingVSS Replacement
Exterior LightsComponent Location Index .......................Circuit DiagramDaytime Running Lights ControiUnit Input Test (Canada) ........................Headlight Ad,ustment .................. .. .....Headlighr Replacement ..............................Combination Light SwitchTest/ReplacementBulb ReplacementTaillight Replacement ..........................High Mount Brake Light Replacement ......License Plate Light Replacement ..............Side Marker Light Replacement ................Brake Pedal Position Switch Test ..............Side Turn Signal Light Replacement ........
Turn Signal/HazardFlasher SystemComponent Location Index .......................Circuit DiagramTurn Signal/Hazard Relay lnputTest ........Hazard Warning Switch Test
22,3
22-7
22-13
22-44
22-46
22-4A
22-49
22-50
22-51
22-53
22-5422-5622-5422 6322-64
22-64
22-6522 61
22-6822--71
22-7 622-7422-79
22-AO22-4122-8222-4222-4322-4322-4422-84
22-8522 A622-8722-88
22-10422-105
22-10622-107
Entry Lights control systemComponent Location Index ....................... 22-89Circuit Diagram ......... 22 90lgnition Key Switch Test .....................,...... 22-9'llgnition Key Light Test ............................... 22-91Control Unit Input Test ..........,.................... 22 92
Interior LightsComponent Location Index ....................... 22-94Circuit Diagram ......... 22-95Ceiling LighVSpotlightsTesVReplacement ................................... 22-96Rear Ceiling Light TesVReplacem ent ........ 22-96Cargo Area Light Test/Replacem ent ......... 22-97Hatch Latch Switch Test ..,..,....................... 22-97
*Audio SystemComponent Location Index ....................... 22-98Circuit Diagram ......... 22,99Audio Unit Removal/lnstallation ............... 22-1OOAudio Unit Connector Replacement ......... 22-101Speaker Replacement ................................ 22-102Roof Antenna Rep1acement ....................-.. 22-103
Rear Window DefoggerComponent Location Index ...........Circuit Diasram .. ....... .. ..... ....... ...:::::.::.::.Function TestDefogger Wire Repair .................................Noise Condenser CapacityTest ................
MoonroofComponent Location Index ....................... 22-1OBCircuit Diagram ......... 22-109Moonroof Control Unit Input Test ............. 22-'l10Switch TesVReplacement ........,.....,........... 22-1 12Motor Test ................. 22-112Limit Swilch Test ...... 22-'l'13Auto-stop Switch Test ................................ 22-1 13
Power MirrorsComponent Location Index ....................... 22-114Circuit Diagram ......... 22-115Function Test ............. 22-116Power Mirror Switch Test .......................... 22-ll7Power Mirror Actuator Test ....................... 22-117Power Mirror Actuator Replacement ........ 22-11A
* HornsComponent Location Index ....................... 22-120Circuit Diagram ......... 22-121Horn TesVReplacement ...........................-. 22-122Horn Switch Test .,.... 22-122
\

Power WindowsComponent Location Index ..........
circuit Diagram . .. ............... .........:.::::.::::.:Master Switch Input Test ...........................Master Switch TestDriver's Window Motor Test .....................
Passenger's Window Switch lnput Test ...Passenger's Window Switch Test .............
Passenger's Window Motor Test ..............
lMaster Switch Replacement ......................
Passenger's Window SwitchReplacement
Wipers/WashersComponent Location Index .......................
Circuit DiagramRear Window Wiper Intermiftent
Control Unit Input Test ...........................Wiper/Washer SwitchTesVReplacementControl Unit Input Test ...............................Wiper Motor Test
Washer Motor TestWasher Fluid Level Switch TesV
Replacement (Canadal ..........................
Windshield Wiper Motor Replacement ....
Rear Window Wiper MotorReplacementWasher Reservoir Replacement ................
Washer Tubes Beplacement ......................
Accessory Power SocketCircuit Diagram ......... 22-149
Accessory Power Socket
TesVReplacement ................................... 22-1 49
Keyless/Power Door Lock System
Component Location Index ....................... 22-150
Circuit Diagram ......... 22-151Keyless Receiver Unit InputTest ............... 22-153
Control Unit Input Test ............................... 22-155
Door LockActuatorTest .........,.......,..,.,..... 22-158Hatch LockActuatorTest ........................... 22-159
Door Lock Knob Switch Test ...................... 22-160
Door Lock Switch Test ................................ 22-160
Transmitter Test ....... 22-161
Transmitter Programming ......................... 22-161
Multiplex Control SystemComponent Location Index ...........
circuit Diagram ...... ........................::.:..:.::.:
Svstem DescriDtionTroubleshootingMultiolex Control Unit InDut Test .............
22 12422-12522-12622-12822-129
22- t30
22-13222 13222-133
22-133
22-134
22-138
22-14022-14122-14322-144
22-14422-145
22-14622-14622 147
22,16422-16922-17'l22,11222-175
lmmobilizer Systemcomponent Location Index ...........
System Description ....... ............. ..:..:..:.:...
Circuit DiagramTroubleshootinglmmobilizer Control Unit-Receiver Replacement ...........................
22-16222-16322-164
22-167

Body Electrical
General Troubleshooting Information (cont'dl
Five-step Troubleshooting
'1. Verify The Complaint
Turn on allthe components in the problem circuit
to verify the customer complaint. Note the
symptoms. Do not begin disassembly or testing
until you have narrowed down the problem area.
2. Analyze The Schematic
Look up the schematic for the problem circuit.
Determine how the circuit is supposed to work by
tracing the current paths from the power feed
through the circuit components to ground. lf
several circuits fail at the same time, the fuse or
ground is a Iikely cause.
Based on the symptoms and your understanding of
the circuit operation, identify one or more possible
causes of the problem.
3. lsolate The Problem By Testing The Circuit
Make circuit tests to check the diagnosis you made
in step 2. Keep in mind that a logical, simple
procedure is the key to efficient troubleshooting.
Test for the most likely cause of failure first, Try to
make tests at points that are easily accessible.
4. Fix The Problem
Once the specific problem is identified. make the
repair. Be sure to use proper tools and safe
proceoures.
5. Make Sure The Circuit Works
Turn on all components in the repaired circuit in all
modes to make sure you've fixed the entire
problem. lf the problem was a blown fuse, be sure
to test all of the circuits on the fuse. Make sure no
new problems turn up and the original problem
does not recur.
22-6
Wire Color Codes
The following abbreviations are used to identify wire
colors in the circuit schematics:
wHT....................,.,.............
YEL......................,,.......,......
B1K......................................
BLU ....,................................
GRN.....................................
RED ....................................,
oRN.....................................
PNK..........................,..........
BRN.....................................
GRY....................................,
PUR.....................................
1T81U..........................,.....
1TGRN...........................,...
White
Yellow
Black
Blue
Green
Red
Orange
Pink
Brown
Gray
Purple
Light Blue
Light Green
The wire insulation has one color or one color with
another color stripe. The second color is the stripe.

Power Distribution
Fuse to Components lndex
Under-hood Fuse/Relay Box
Fuse
Number
AmpsWire ColorComponent(sl or Circuit(s) Protected
'I204BLUI/ELCondenser fan motor
BLU/REDAy'C compressor clutch
15AWHT/GRNDash lights, Front parking lights, Front side marker lights, License plate
liqht, Rear side marker liqhts, Tailliqhts
7.5AWHT/BLUCarqo area liqht, Ceilinq liqhts. lqnition Kev liqht. Sootliohts
204BLU/BLKRadiator fan motor
510AWHT/BLKTurn siqnal/hazard relav, Turn siqnal liqhts
15AWHT/BLKCKP sensor, ECM, IAC valve, lmmobilizer control unit-receiver, Injectors,
PGM-FI main relav 1 and 2. TDC sensor
715AWHT/GRNBrake lights, Brake signals (to ABS modulator-control unit, Cruise control
unit, ECM)
BLU/REDi1 Orns
820AWHT/GRNABS modulatorcontrol unit
910AWHT/REDAudio unit, Data link connector (DLC), Gauge assembly, lmmobilizer
control unit-receiver, lmmobilizer indicator light. Keyless receiver unil,
lvlultiDlex control unit
1040AWHT/REDABS modulator-control unit
1130AB LK/YE LNoise condenser, Rear window defoqqer
40ABLU^^/HTBlower motor
IJ40AWHT/BLKNo. 7 fuse (in the under-dash fuse/relav box), Power window relav
1440AWHT/REDNo.2 and No.3 fuses (in the under-dash fuse/relav box)
t515AREDI/ELDaytime running lights control unit (Canada), Daytime running lights relay
{Canada), Hioh beam indicator liqht. Left headliqht
16204WHTMultiplex control unit
1715AREDDavtime runninq liqhts control unit (Canada). Rioht headlioht
1860AWHTiBLUEPS control unit
1980ABatterv. Power distribution
2040A'
50A'?
WHTlgnition switch (BAT)
* 1: USA" 2. Canada
O: Spare fuse
t t"| lll Itt 4t I
l l---- E'l E,l E,l r--r r---r t__J i; i6'!/'
E,l E,l E,l Eol E l f__--lI l'lr]n | |I r L__J,a ,..r^{-------l^-,
n[:]$"Lrt " N2, nf - r^l
22-46

Under-dash Fuse/Relay Box
Fuse
Number
AmpsWire ColorComponent(s) or Circuit(s) Protected
115ABLKA/VHTlgnition coils
2204WHT/REDAirlfuel ratio sensor, ECM
310ARED/BLUDaytime running Iights control unit {Canada)10ABLI(ORNAir/fuel ratio sensor relay, Alternator, CMP sensor, Cruise control main
switch, Cruise control unit. ELD unit, Evaporative emission (EVAP) bypass
solenoid valve, Evaporative emission (EVAP)canister purge valve,
Evaporative emission (EVAP) canister vent shut valve, Secondary H02S,
Vehicle speed sensor
5Not used
67.5AYEUGRNMoonroof control unit, Moonroof open and close relay, Power window
relaV
7204GRNMoonroof motor
I7.5AYEUREDAudio unit
910AGRNOPDS unit, Rear window wiper motor, Rear window washer motor, Rear
window wiper intermittent control unit
107.54YELBack-up lights, Cruise indicator light, EPS control unit, Gauge assembly,
Keyless receiver unit, Multiplex control unit, Security control unit
connector (optional)
117.5ABLIVORNABS modulator-control unit
127.5AYEUREDDaytime runnino liohts control unit (Canada)
1310APNKSRS unit't410ABLK/YE LA,,/C compressor clutch relay, Blower motor relay, Condenser fan relay,
Heater control panel, Power mirror actuator, Power mirror defogger(Canada), Radiator fan relay, Rear window defogger relay, Recirculation
control motor1ENot used
loNot used
1715AYE L/B LKECM, Fuel pump
B LK/YE L>H> Unrr
1815AYEUGRNAccessory power socket
197.5AYEUBLKTurn siqnal/hazard relav, Turn siqnal liohts
2030AGRN/BLKMultiplex control unit, Windshield washer motor. Windshield wioer motor21Not used
22204GRN/BLKPassenqer's window motor
2320A.G R N,A/VHTDriver's window motor
24Not used
25Not used
__^:Hr tl_l
f at-t
at I
r^,rl fl
!!;r -
!339,i;s!!sf Fnf : |rnITf
22-47