2003 HONDA CIVIC fan

Fuse/Relay Boxes
Connector to Fuse/Relay Box Index
Under-hood Fuse/Relay Box
lview of tront sidel
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------tttL""tt tt ttL lL ltl'".-
{View of back side)
SocketRefTerminalConnects to
Ay'C compressor clutch relay
B
Blower motor relay
c
Condenser fan relay
D
E
ELD unit
Headlight relay 1
Headlight relay 2
Horn relay
Radiator fan relay
Rear window defoqqer relay
14
2
15
91'
11
to
5
6
10'l
J
2
4
5
4
4
14
7
3
4
4
4
4
Engine compartment wire harness (see page 22-18)
Engine compartment wire harness (see page 22-18)
Engine compartment wire harness (see page 22-18)
Engine compartment wire harness (see page 22-18)
Engine compartment wire harness (see page 22-18)
Engine compartment wire harness {see page 22-18)
T1 (Batterv)8Starter subharness (see oaqe 22-15)
T101 (Alternator)7Starter subharness {see oaoe 22-'15}
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I tTt Tr,/^-------lFrr^l -/1-l sz- l:!)L' lrt
22-44

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
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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
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at I
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22-47

Ground Distribution
Ground to Components Index
GroundComponent or circuit qrounded
Batterv, Transmission housinq
E ngine
G 101ECM (PG is BLK; LG is BRN/YEL)
BLK: IAC valve, lgnition coils, Vehicle speed sensor, VTEC solenoid valve
BRNA/EL: Camshaft oosition (CMP) sensor. CKP sensor, TDC sensor. VTEC oil pressure switch
G 15']EPS control unit
G201ELD unit. Multiplex control inspection connector, Multiplex control unit, Power window relay, Rear
window washer motor, Right front parking light, Right front side marker light, Right front turn signal
light, Turn signal/hazard relay, Washer fluid level sensor (Canada) , Windshield washer motor,
Windshield wiDer motor
G202ABS modulator-control unit
G301
G401
Blower motor relay, Brake fluid level switch, Condensor fan motor, Cruise control actuator, Left front
parking light, Left front side marker light, Left front turn signal light, Radiator fan motor, Radiator fan
swrtcn
Combination liqht switch, lqnitlon kev srvitch, Wiper/wasfrer sr,virch
G402Left and riqht airbaq sensors, SRS unit
G 451Data link connector (DLC)
G501Clutch interlock switchm Clutch pedal position switch (for cruise control), Cruise control main switch,
Cruise control unit, Daytime running lights control unit (Canada), Driver's door lock knob switch,
Driver's door lock switch, Driver's power window motor, Heater control panel, Left power mirror
defogger (Canada), left side turn signal light, Moonroof control unit, Monroof open and close relays,
Moonroof position sensor '1, Moonroof seitch, Power mirror switch, Power transistor, Power window
master switch. SDotliqhts
G502Accessory power socket, Gauge assembly, Keyless receiver unit, lvlultiplex control unit, Right power
mirror defogger {Canada)
G503Audio unit
G551Driver's seat belt switch, Fuel gauge sending unit, Fuel pump, Memory erase signal (IMES) connector,
OPDS unit. Rioht seat belt switch
G552High mount brake light, License plate lights, Rear window defogger, Rear window defogger noise
condenser. Rear window wioer motor, Hatch latch switch
Back-up lights, Brake lights, Rear side marker lights, Rear turn signal lights, Rear window wiper noise
condenser, Rear window wiper intermittent control unit, Taillights
22-48

Relays
Power Relay Test
Use this chan to identify the type of relay, then do the
test listed for it.
NOTE: Turn signal/hazard relay input test (see page 22-
87).
RelayTest
A'lC comoressor clutch relavNormally-open
type AAirlfuel ratio sensor relav
Condenser fan relay
Headlioht relav 1
Headliqht relav 2
Horn relav
Power window relay
Radiator Ian relay
Reverse relav
Starter cut relav
Tailliqht relaV
Daytime running lights relay
{Canada )
PGM-FI main relav 1
PGM-Fl main relav 2
Blower motor relavNormally-open
tvpe BRear window defoqoer relav
Moonroof close relayFive terminal
typeMoonroof oDen relav
Low beam cut relav {Canada)
Normally-open type A:
Check for continuitv between the terminals.
. There should be continuity between the No. 1 and
No,2 terminals when power and ground are
connected to the No. 3 and No. 4 terminals.. There should be no continuity between the No. 1 and
No.2 terminals when power is disconnected.
type 1:
type 2:
PGM-FI main relay 1
PGM-FI main relay 2
type 1:
type 2:
(cont'd)
22-51

4. Make these input tests at the connector,
.lfanytestindicatesaproblem,findandcorrectthecause,thenrecheckthesystem.
. lf all the input tests prove OK, the control unit must be faulty. Replace it.
CavityWireTest conditionTest: Desired resultPossible cause if result is not obtained2R E D/BLUUnder all
conditions
Check for voltage to ground:
There should be battery voltage.
Blown No. 14 (40A) fuse in the
under-hood fuse/relay box
Blown No. 3 {10A)fuse in the
under-dash fuse/relay box
An open in the wire12YE L/RE Dlgnition switch
oN (r)Check for voltage to ground:
There should be battery voltage.
Blown No. l2 (7.5A)fuse in the
under-dash fuse/relay box
An open in the wire
BLKUnder all
conditions
Check for continuity to ground:
There should be continuitv.
. Poor ground {G50'1). An oDen in the wire7BLKUnder all
conditions
Check for continuity to ground:
There should be continuitv.
. Poor ground (G501)
' An open in the wire
10REDI/ELCombination
light switch ON/ =f\
Check for voltage to ground:
There should be battery voltage.
Blown No. 15 (15A) fuse in the
under-hood fuse/relay box
Faulty headlight relay 2
Faulty combination light switch
An open in the wire
1RED/B LUCombination
light switch ON
{iD), and
dimmer switch
in HIGH
Connect a jumper wire between
No.3 and No. 1 terminals.
Both headlights (HIGH) and
h igh beam indicator light
should come on.
Blown bulb
Faulty low beam cut relay
Faulty combination light switch
Poor ground (G50'l )
An open in the wire'11
3
RED/BLK
GRN/BLK
Combination
light switch ON(iD), and
dimmer switch
in HIGH
Com bination
light switch ON(iD), and
dimmer switch
in HIGH
Connect a jumper wire between
No. 5 and No. 11 terminals.
Right headlight (HIGH) should
come on.
Check for continulty to ground
There should be continuity.
. Blown bulb. Faulty combination light switch. Poor ground (G 50'1 ). An open in the wire
. Faulty combination light switch. Poor grou nd {G501). An open in the wire
5
6GRN/ORNParking brake
lever oulled
Check for continuity to ground:
There should be continuitv.
Faulty parking brake switch
An open in the wire
8BLU/REDCombination
light switch OFF
Check for voltage to ground:
There should be battery voltage.
Faulty headlight relays
Short to ground
An ooen in the wire
WHT/BLUlgnition switch
oN 0r)
Attach to ground:
The DRL indicator light should
come on.
. Blown No. 10 (7.5A) fuse in the
under-dash fuse/relay box. Faulty DRL indicator. An ooen in the wire
t5G RN/REDlgnition switch
oN (||)Attach to ground:
The brake system light should
come on.
Faulty brake system indicator
An open in the wire
22-77

Turn Signal/Hazard Relay Input Test
1. Removetheturn signal/hazard relay (A) from the under-dash fuse/relay box (B).
Inspect the relay and fuse/relay box socket terminals to be sure they are all making good contact
. lf the terminals are bent. loose, or corroded, repairthem as necessary, and recheckthe system.
. lf the terminals look OK, go to step 3.
Make these input tests at the fuse/relay box.
.lfanvtestindicatesaproblem,findandcorrectthecause,thenrecheckthesystem.
. lf all the inputtests prove OK,theturn signal/hazard relay must befaulty. Replace it
000i 0!1000
00u! u0
CavitvTesl conditionTest: Desired resultPossible cause il result is not obtained
1Under all conditionsCheck for continuity to ground:
There should be continuiw.
. Poor ground (G201)
. An ooen in the wire
3lgnition switch ON ( ll)
Hazard warning switch
OFF
Check for voltage to ground:
There should be battery voltage.
' Blown No. 19 (7.5A) fuse in the
under-dash fuse/relay box. Faulty hazard warning switch. An ooen in the wire
Hazard warning switch
ON
lgnition switch OFF
Check for voltage to ground:
There should be battery voltage.
. Blown No. 5 {10A) fuse in the
under-hood fuse/relay box. Faulty hazard warning switch. An ooen in the wire
2lgnition switch ON ( ll)
and turn signal switch
in Right or Left position
Connect No. 2 terminalto No. 3
terminal:
Right or left turn signal lights
should come on.
. Poor ground (G201, G301, G501,
G502, G553). Faulty turn signal switch. An oDen in the wire
lgnition switch OFF
Hazard warning switch
ON
Connect No.2 terminal to No. 3
termrnal:
Hazard wa rning lights should
come on.
. Poor ground (G201, G301, G501,
G502, G553). Faulty hazard warning switch. An open in lhe wire
22-87

I
5. With the connectors stilldisconnected, make these input tests at the connector'
. lf anv test indicates a problem, find and correct the cause, then recheck the system. lf all the inpul tests prove OK, go to step 6.
6.Reconnect the connectors to the under dash fuse/relaV box, and make these input tests at the appropriate connectors on the under-dash
fuse/relay box.
.lfanytestindicatesaproblem,findandcorrectthecause,thenrecheckthesystem..lfalltheinputtestsproveOK,themultiplexcontrolunitmustbefaulty.Replacetheunder'dashfuse/relaYboxassemblY
CavitvWireTest conditionTest: Desired resultPossible cquse il result is not obtained
K28LU/ORNlJnder allconditionsCheck for continuity between the K2terminal and the keyless receiverunit 5P connector No. 2 terminal:There should be continuitv.
An open in the wire
o7GRN/REDCejling light switch inmiddle position.Attach to ground:Ceiling light(s)should come on.Blown No. 3 (7.5A) fuse in the under hood
Blown bulbFaulty ceiling lightAn ooen in the wire
X8WHT/BLKUnder allconditionsAttach to ground:lgnition key light should come on.Elown No.3 (7.5A)fuse in the under hoodfuse/relay boxFaulty ignition key light (LED)
An ooen in the wire
CavitvWireTest conditionTest: Desired resultPosq!!!c sq!!ej1!.9!!!!j €d
P18REDHatch openCheck for voltage to ground:There should be 1 V or less.Poor ground (G552)
Fauhy hatch latch switchAn open inthewire
Hatch closedCheck for voltage to ground:There should be 5 v or more.Faulty hatch latch switchShortto oround
Q3GRNDriver's door openCheck for voltage to ground:There should be 1 V or less.Faulty drlver's door switchAn oDen in the wire
Driver's door closedCheck for voltage to ground:Thar. shoul.l he 5 V or more.Faulty driver's door switch
o4LT GRN/BED
RED^vHT
Passenger's doorCheck for voltage to ground:There should be 1 V or less.
' Faulty passenger's door switch' An onen inthewire
Passenger's doorcroseoCheckfor voltage to ground:There should be 5 Vor more.
. Faulty passenger's door switch. Shor o oround
X5lgnition key insertedinto the ignitionCheck for voltage to ground:There should be 1 V or less.Poor ground (G401)
Faulty ignition key switchAn ooen in the wire
lgnition key removedfrom the ignitionCheck for voltage to ground:There should be 5 V or more.Faulty ignition key switchShort to ground
Y8YEUREDDriver's door lockknob switch lockedCheck for voltage to ground:There should be 1 V or less.Poor ground {G501)Faulty driver's door lock knob switchAn ooen in the wire
Driver's door lockkn6h cwirch Inl6cke.lCheck for voltage to ground:There should be 5 V or more.Faulty driver's door lock knob switchShort to oround
22-93