1997 HONDA CIVIC Horn relay

Circuit Diagram
N0.30 (7.5A)
f/
IREO/BtX
WNT/BLK +WNT
BLU/RED
VHORN
IJ,
JRN,/WH
VgRAKELGHTS
UNDER.HOOD FUSEi RELAY 8OXUNDEB.OASH FUSARELAY BOX
GRY + BLUiGRN
GAUGEASSEMBLY
CBUISECONTROLACTUATOR
N0.41 (80A) N0.42 {40A)
INOICATORLIGHT(0.84rY)
lPIO SET
lo
I Q suue
tGNlTtoN swlrcH
l-t* : 99 00 models wlli A/T
23-241

)
CavityWireTest conditionTest: Desired resultPossible cause if result is not obtained
BRNA/VHTUnder all conditionsCheck for resistance to ground:
There should be 80 - 120 O.
Fau lty actuator solenoid
Poor ground (G202)
An open in the wire
1BRNUnder all conditionsCheck for resistance to ground:
There should be 40 - 60 0.
11BRN/BLKUnder all conditionsCheck for resistance to ground:
There should be 70 - 110 0.
2GRY
lgn jtion switch ON (ll),
main switch ON and
brake pedal pushed,
then released
Check for voltage to ground:
There should be 0 V with the Pedal
pushed and battery voltage with
the pedal released.
'Faulty brake switch
. An open In the wlre
3BLKU nderall conditionsCheck for continuitY to groundl
There should be continuity
' Poor ground (G401, G402)
. An open in the wire
5GRNA,A/HT
Brake pedal pushed,
then released
Check for voltage to groundl
There should be batterY voltage
with the Pedal Pushed. and 0 V
with the pedal released
. Blown No. 52 (15 A) fuse in the
under-hood fuse/relaY box
. Faulty brake switch. An open in the wire
LT GRN/
RED
Set button pushedCheck for voltage to ground:
There should be batterY voltage.
Blown No. 52 (15 A) fuse in the
under-hood fuse/relaY box
Faulty horn relay
Faulty sevresume switch
Faulty cable reel
An open in the wire7LT GRN/
BLK
Resume button Pushed
10RED/BLU
lgnition switch ON (ll)Attach to ground:
Cruise indicator light in the gauge
assembly should come on.
Blown bulb
Blown No. 25 (7.5 A) fuse in the
under dash fuse/relay box
Faulty dimming circuit in the
gauge assemDly
An open in the wire
BLU,A/VHT
lgnition switch ON (ll)
and main swilch ON;
raise the front of the
car, and rotate one
wheel slowly with the
other wheel blocked.
Check for voltage between the
BLUMHT @ and BLK O terminals:
There should be 0- 5 V or more
-0- 5 V or more repeatedlY
. Faulty vehicle speed sensor {VSS)
. An open in the wire
LT GRN
lgnition switch ON (ll)
and main switch ON
Check for voltage to ground:
There should be batterY voltage.
Blown No. 14 (7.5 A)fuse in the
under-dash luse/relaY box
Faulty main switch
An open in the wire
14PNK
A,T: Shift lever in E,
ojorE
M/T: Clutch pedal
released
Check for continuity to ground:
There should be continuity.
NOTE: There should be no conti-
nuity when the clutch Pedal is
depressed or when the shift lever
is in other positions.
Faulty A/f gear position switch
Faulty or misadjusted clutch
switch (M/T)
Poor ground (G401, G402)
An open in the wire
BLU/GRN
Under all conditionsCheck for continuity between No. I
terminal and No. 5 terminal of the
PCM connector A.
There should be continuity
. An open in the wire
*: '99 - 00 models with A,/Tl-,
23-243

I
Reconnect the 18P connector to the power door lock control unit
Cavitv Wire Test condition Tost: Desired resultPossible cause it r€sult is not obisinod
23-261
l-l
'10GRNA/VHTDriver's door lock
switch in LOCK
Check for voltage to groundl
There should be 1 V or less.
. Faulty driver's door lock switch. Poor grou nd (G551)
. An open in the wire
9GRN/ORNDriver's door lock
swirch in UNLOCK
2BLU,ryVHT
Driver's door lock knob
in LOCK
Check for voltage to ground:
There should be 1 V or less.
Faulty driver's door lock actuator
Poor ground {G551)
An open in the wire
3BLU/RED
lgnition key inserted
into the ignition key
swttcn
Check for voltage to groundl
There should be 1 V or less
Check for voltage to ground:
There should be 4 V or more
Ch."k f"r ".lt"r" t. g|'"r^d
There should be banery vollage
Poor ground (G401, G402)
Faulty ignition key switch
An open in the wire
Shon in the wire
A o*n tto gO ,i5 A' fr." in tf'"
Lrnder hood fuse/relay box
Faulty combination light switch
An open in the wire
lgnition key removed
from the ignition key
swtrcn
RED/BLK
Combination light
switch in " :m: "
position
LT GRN/
RED
Each door open, one at
a trme
Check tor voltage to ground:
There should be 1 V or less.
Faulty door swilch
An open in the wire
GRY
U nder all conditionsBlown No. 52 (15 Al fuse in the
under hood fuse/relay box
Faulty horn
Fau lty horn relay
An open in the wire
Connect to ground:
Horn should sound.

)
l-l
Disconnect the A and B connectors from the audio unit.
Cavity WireTest conditionTest: Desired resultPossible cause if result is not obtained
Reconnect the B connector only to the audio unit.
Cavity WireTest conditionTest: Desired resultPossible cause iI result is not obtained
B9GRN/ORN
Driver's door lock
switch in UNLOCK
Check for voltage to ground:
There should be 1 V or less.
. Poor ground 1G551). Faulty driver's door lock switch. An open in the wire. Short in the wireDriver's door lock
switch in LOCK
Check for voltage to grou nd:
There should be 4 V or more.
810G R NAr'r'HT
Driver's door lock
switch in UNLOCK
Check for voltage to ground:
There should be 4 V or more.
. Poor ground (G551)
. Faulty driver's door lock switch. An open in the wire. Shon in the wireDriver's door lock
switch in LOCK
Check lor voltage to ground:
There should be I V or less.
23-263
A4WHT/BLU
LJnder all conditionsCheck {or voltage to ground:
There should be battery voltage.
. Blown No. 47 (7.5 A) tuse in the
under hood fuse,i relay box. An open n the w re
A5YEL/RED
lg nition swirch ACC (l)Check for voltage to ground:
There should be battery voltage.
Blown No. 28 , I0 A) f use in the
under dash fuse.elay box
An open " :ne n re
Check for voltage to ground:
There should be battery voltage.
Check for continuity to groundr
There should be continuity.
B o$. \. '.1 - 5 A' iuse n the
,,^oe' aas_'-se relay box
A_ ooe^ ' :ne wrre
Pc.' E'o--d rG401, G402)
A- ooen n lhe wire
B6B LK,/YE L
lgnition switch ON0l)
8158LK
Under all conditions
B1BLU/RED
lgnition key inserted
into the ignition key
swrtch
Check for voltage to ground:
There should be 1 V or less
Check for voltage to ground:
There should be 4 V or more
Poor ground (G401, G402)
Faulty ignition key switch
An open in the wire
Short in the wire
An open in the wireCheck for continuity berwee. lFe
audio unit 16P connector l-o 3ler-
minal and power door lock control
unit 12P connector No. 6 lermrnal:
There should be continu ty
lgnition key removed
from the ig nition key
swtlcn
B3B LUlt/E L
U nderall conditions
B8LT GRN/
BLK
Ceiling light switch in"middle position"
Connect to ground:
The ceiling lighr shouldcome on.
Blown No.43 (7.5 A) fuse in the
under-hood Iuse/relay box
Blown ceiling light bulb
Fau lty ceiling light
An open in the wire
814LT GRN/
RED
Each door open, one at
a time
Check tor voltage to ground:
There should be'l V or less.
. Faulty door switch. An open in the wire
Br6GRY
U nderall conditionsConnect to groundl
Horn should sound.
. Blown No. 52 ('15 A) fuse in the
under-hood fuse/relay box
. Fau lty horn. Faulty horn relay. An open in the wire

Component/Wiring Locations
)
Index: With Front Passenger's Airbag
SRS INDICATOR LIGHT (ln the gauge assemblvl
Troubleshooting, Page 24 13
Gauge assembly, section 23CABLE REEL
Replacemenlpage 2!-t 2
To HORN SWITCH
SRS UNIT(lncluding safing sensor
and imPact sensorl
Replacement Page 24 76
To DRIVER'S AIRBAG
DASHBOARD WIRE HARNESS
to SRS INDICATOB LIGHT in
GAUGE ASSEMBLY5P CONNECTOB
DBIVER'S AIRBAG
Beplacement,page 24-61Disposal, page 24 70FRONT PASSENGER'S AIBBAG
Replacement, Page 24_67
Disposal, Page 24 70
t
SRS MAIN HARNESSto CABI-E RE€L2P CONNECTOR
SRS MAIN
SERVICE CHECKCONNECTOR {2PI
IBRN, BLK]
to UNOER-OASHFUSE/RELAY BOX2P CONNECTOR
SRS MAIN HARNESSto FRONT PASSENGER'SAIRBAG2P CONNECTOB
SRS MAIN HARNESSto SRS UNITr8P CONNECTOR
SBS MAIN HARNESSto MAINWIRE HARNESS3P CONNECTOR
MEMORY ERASE SIGNAL(MES) CONNECTOR I2P)
[GRY, GRYI or IGRN. GRNI
MAIN WIRE HARNESSto DASHBOARD WIRE HARNESS
24P CONNECTOR
2+3
t,

Gomponent/Wiring Locations
Index: Without Front Passenger's Airbag (some Canada Modelsl
SRS INDICATOR LIGHT (ln the gauge assembly)Troubleshooting, page 24-13Gauge assembly, section 23
DRIVER'S AIRSAGReplacement,page 24-67Disposal, page 24-70
SRS UNITGROUNO
To HORN SWITCH
SRS MAIN HARNESS
SRS UNIT{lncluding safing sensorand impact sensor)Replacement. page 24,76
To CRUISE CONTROLSET/RESUME SWITCH
oo/ \oo
To DRIVER,S AIRBAG
DASHBOARD WIRE HARNESSto SRS INDICATOR LIGHT inGAUGE ASSEMBLY5P CONNECTOR
SERVICE CHECKCONNECTOR {2P}IB8N, BLKI
SRS MAINto UNDER-DASHFUSE/RELAY BOX2P CONNECTOR
SRS MAIN HARNESSto SRS UNIT18P CONNECTOR
SRS MAIN HARNESSto MAINWIREHARNESS3P CONNECTOR
MEMORY ERASE SIGNAL(MES) CONNECTON (2P'
IGRY, GRYI o. IGRN, GRNI
MAIN WIRE HARNESSto DASHBOARD WIRE HARNESS24P CONNECTOR
24-4
DUMMY RESISTOB

Contents
How to Use This Manual ICircuit Schematics (see Circuit Index)Fuse/Relaylnformation 6Ground-to-Componentslndex 6-6ComponentLocationPhotooraohs 201Conriector Views 202
Circuit Index
Accessory power socket 155Air conditionerAir delivery'96198 models 61'99-'00 models 61-2Blower controls'96198 models 60'99100 models 60-1Compressor controls 62Fans 63Anti-lock brake system (ABS) 44A/T gear position indicatorCVT 89All except CVT 89-1Automatic transmission controlsAll '96-'98 models except CVT and GX 39All '99100 models except CVT 39-8All GX models 39-8'96-'98 CVT 39-4'99100 cw 39-12Back-up lightsCoupe and Sedan 110Hatchback l'10-1Brake lightsAll Coupes and'96-'98 Sedans 110-15'99-'00 Sedans 110-16Hatchback 110-17Brake system indicator light'96198 models 7'1'99100 models 71-1Ceiling light 114-3Charging system 22Condenser fan 63Console lights 114Cruise control 34Dash lights 114Daytime running lights 110- 13Engine coolant temperature gauge 81-1Fog lights 110-10Front parking lights 110-2Fuel gauge 81-1Fuse/relay boxUnder-dash 6Under-hood 6-4Underhood ABS 6-3Gauges 81Ground distribution 14Ground-to-Componentslndex 6-6Hazard warning lightsAll except '99100 Sedans 110-6'99100 Sedans 110-8Headlights 110-12Headlight switch 100Heater - See Air ConditionerHorn'96197 models 40'98 model 40-1'99100 models 40-2lgnition key reminder 73lgnition systemAll '96198 models except Dl685 20All '99100 models except D16Y5 with Mn 2O-2All D1685 engines 20-2'99-'00 D 16Y5 with M/T 20
lndicators 80Integrated control unit 70lnterlock systemAll except'96J98 CVT 138'96198CVT 138-1License plate lightsAll Coupes and '96-'98 Sedans I l0-3'99100 Sedans 1 10-4Hatchback 110-5Low fuel indicator light 74Moonrool'96197 models |22'98-'00 models 122-1Odometer 81Oil pressure indicator light 80-3Power distributionBattery to ignition switch, fuses, and relaysFuses to relays and components 10-2Power door locksAll models without keyless entry 130'96-'98 models with keyless entry 130-2'99100 models with keyless entry 130-12Power mirrorsWithout detogger 141With defogger '141-2
Power windows 120Programmed fuel injection system (PGNr-Fl)All '96-98 models except D1685 23All '99-'00 models except D16Y5with M/T and D1685 24All D1685 engines 25'99100 D16Y5 with M/T 23Radiator fan 63Rear window defogger'96-,98 models 64'99100 models 64-1Seat belt reminder 73Security system'96.'98 USA HX, LX, EX 133'96-'98 Canada EX, Si 133'99TOO USA HX, LX, EX, DX.V Si 133-4'99100 Canada EX, Si 133-4All CX and DX models 133-8Speedometer 81Starting systemA./T (All except Dl685) 21A"/r (D16Bs) 21-1Manualtransmission 21-2Slereo sound system 150Supplemental rastraint system (SRS) 47Tachometer 81TailliqhtsAllboupes and'96-'98 Sedans 110-3'99100 Sedans 1 10-4Hatchback 110-5Trunk light 114-3Turn signal lightsAll except'99100 Sedans 110-6'99-'00 Sedans 1 10-8Vehicle speed sensor (VSS) 33Wiper/washerFront 91Rear 92
10

Fuse
NumberFuse NameAmpsPage
BATTERY
Component or Circult Protected
Power distribution
lgnition switch
INTERIOR LIGHT | 7.5 | 10-10 | DLC, Ceiling light, Trunk light
FI E/M15 i(20 GX) i
i PGM-FI main relay, Fuel injection relay (GX)
Not used
POWER WINDOW| 10-10 | Power window relay
BACK UPStereo radio iuner ('9G'98 mod€ls), Audio unit ('99100
models), Heater control panel, PCM/ECM, TCM (9e'98
cvr)
HEADLIGHT
REAR DEFROSTER I
DOOR LOCK UNIT,
ROOF
i 10-12i Headlights
Not used
Rear window defogger relay
Power door lock control unit (all except '99-'00 models
with keyless), Keyless door lock control unit ('99-'00
models with keyless), Moonroof
i HORN, SrOP Lri 10-13i Horn relay, Brake switch
HAZARDHazard warning switch
OPTIONI 10-13I Security system (option)
i HEATER MOTOR Ii 10-1 i Blower motor relay
(CONDENSER FAN)
COOLING FANl1o-1
Condenser Jan relay, A'lC compressor clutch relay
Radiator tan relay
&5