2000 HONDA CIVIC Horn circuit

l'f .
Electrical
Special Toofs .,....................,23-2
Troubleshooting
Tips and Precautions ..............,.................... . 23-3
Five-step Troubleshooting .............. ......... . . 23-5
wire color codes ..........,23-5
Schematic Symbols ........,................... . . .. .... 23-6
Relay and Control Unit Locations
Engine Compartment ...,..................... ... .. . 23'7
Dashboard ......................23-8
Dashboard/Door ......... 23-12*Airbags ................. ....... Section 24
Air Conditioning ......... Section 21
Aftelnator ..........."""" """ 23-112
Anti-lock Brake System {ABS) Section 19*A/T Gear Position Indicator .....................,. .... ... 23-149
Automatic Transmission Svstem .... . ....... Section 14
Batterv ......... . . . ... ...... .......23-91
Blower controls .. . ... Section 2l
Charging System ....'...........23'112
Connector ldentilication and Wire Harness
Routing .................. ......23'13
Cruise Control ............,........23-240
Dash Lights Brightness Controller ............. ....... 23-180
Fan controfs "" 23'126
Fuel PumD ........ . ........ section 11
Fuses/Refay ...............,..,,.. 23'62
PGM-FI Control System ......................,....... Section 1 1
*Gauges
Circuit Diagram ....,.,.......23-131
Fuef Gauge ...........'.'.......23-142
Gauge/lndicator .. . .. 23-129
Ground Distribution .. . 23-75
Heatei controls .. . ..... Section 21*Horn................. ...............23-196
*tgnition Switch ....................23-89
lgnition System .......,.... 23-102
*lntegrated Control Unit ....................................... 23-156
fnterlock System ,........ . . , ,23-144
Lighting System . . . .. ......... 23-161
Lights, Exterior
Back-up Lights ..'............23'171
Brake Lights .................. 23'174
Daytime Bunning Lights (Canadal ............... 23'166
Front Parking Lights ......,................ .'. .......... 23-167
Front Turn Signal Lights .......... . . ............ ..,.23-167
Headtights ....".'....-... ..... 23'167
High Mount Brake Light ...................... ... .23'179
License Plate Lights ...... 23'176
Taitfights ................ .......23'171
lnterior Lights ..-.......,, . 23-142
Moonroof ..,.................,........ 23-235
Power Distribution ....... . . .23-61
Power Door Locks .......,,,. .23'251
Power Mirrors ,..............,.,...23'206
Power Relays ....... . ...... . . .. 23-86
Power Windows ............,,....23-220
Rear Window Defogger .......................... . . ... . . 23-2OO
Spark Plugs . ..... . ........ .....23-111
Slarting System ................23-93*stereo Sound Svstem ,................. ..... ... . ... ,.,.,,23'147'Supplemental Restraint System (SRS) ... . Section 24
Turn Signal/Hazard Flasher System .......'.'....-... 23-173
*Undel-dash Fuse/Relay Box ............,.................. 23-85
vehicfe soeed sensor (VSSI """" ""' 23-140+Wipers/Washers .........,.,.,...23-214
NOTE: Unless otherwise specified, references to auto-
matic transmission (Mf) in this section include the CVT.

Troubleshooting
Schematic Symbols
BATTERY
E
@
GROGroLrnd terminal
II_d:
UNDComponent ground
II_..'-
FUSE
--cn-.e
COIL, SOLENOID
r{r
tql'|
CIGARETTE LIGHTER
A
lrl
P
RESISTOR
I
f
VARIAELE RESISTOR
ilH
THERMISTOR
c
IGNITION SWITCH
-fo o.t-
BULB
+
HEATEB
At-l
F
MOTOR
0
PUMP
H
CIRCUIT BREAKER
I
r
Yr
T
HORN
+
DIODE
+
SPEAKER, BUZZER
D
Mast
Y
ANTt:f\,NATRANSISTOR lTrl
II
SWITCH (ln niNormally open
I
/F\t tL I\Y/
I
rrdal positionlNormally closed'*i."n
@
I
LIGHT EMITTINGDIODE ILEDI
A+,
TT
RELAY lln noNormally opon relay
| ....--1'rl*r
til
t "t^f
fmal poaitionlNormally closed relay
ffl-+- |
lrl
lrl
fff
CONDENSER
I
T
CONNTInput
V
I
:CTIONOutput
J
CONNECTOR
*>-
'l!
REED SWITCH
A
tftl
Y

(l'-
Fuse NumberAmpswire ColorComponent(s) or Circuitlsl Protect€d
4180APower distribution
4240AWHT/BLKTo ignition switch (BAT)
437.5 AWHT/REDCeiling light, data link connector, trunk light
4415 AWHT/BLKPGM-Fl main relay
Not used
4640AWHT/BLUPower window motors (via power window relay)
477.5 AWHT/BLUAudio unit, clock, TCM (CVT), ECM/PCM (VBU)
4830AWHTNo.33 (7.5 A) fuse, To combination light switch (headlight)
49Not used
5030AWHT/GRNRear window defogger (via rear window defogger relay)
cl20AWHT/GRNPower door lock control unit, moonroof motor
15 AWHT/GRNHorn system, brake lights, brake signal
10 AWHT/BLKHazard warning light, turn signal/hazard rclay
54404WHT/REDOption {+B)
5540ABLU,A/VHTBlower motor (via blower motor relay)
204WHTCondenser fan motor (via condenser fan relay)
REDl'lc compressor clutch (via IVC compressor clutch relay)
204BLVBEDRadiator fan motor (via radiator fan relay)
23-6

Brake Lights
WNT/GRN
Circuit Diagram
UNDEH HOODFUSEiRELAYBOXBATTERY/-l I No s2 (1sA) |
u/T'\--]-wHrGFNTwfciN_l
tvHORN SYSTEM
INNERTAILL]GHT
GRNMHT
I
AE-'ii,t
Yut#l
IBLK
ffi; I
I l,"l
I I''i
Li;
GRN,4fiHT
l**,,,,I P } BRAKE
Y ilT'
I
I
I
IgLK
I
I:
flatchbackCoupe/SedanSedan 99 mode
ffi; I
i $*i
iri
Li*'']
GRNMHT
I
A b'rt^t-,
Yllf,ll
IBLK
BLK
I
I
I
G601 r Halchback/Coupe/Sedan
BLK
II
II
I
G601 : Haldbackiooup€/Sedan G761 :G601 :G602 :
+ 21W :Coup€/Sedan18W :HalchbackJ I : Wilh cruise control
23-178

Circuit Diagram: '96 - 97 models
HORNRELAY
WHT/GRN
I(H)HoRN
Y
IBLU/REO
I
I
IBtK
I
t-l
G40lG1A2
BATTERY
l-
23-197
Horn Test: '96 - 97 models
1. Remove the front bumper (see section 20).
2. Disconnect the 2P connector from the horn.
Remove the horn.
Test the horn by connecting battery power to one
terminal and grounding the other, lf the horn fails to
sound, replace it.
3.
LOW HORN

Horn
Circuit Diagram: '98 - 00 models
HCRI]tEtA'a
BATTEFY
1 '98 model: WHT/GRN'99 - 00 modelsr BLU/RED
23494
Horn Test: '98 - 00 models
'1. Remove the f.ont bumper (see section 20).
2. Disconnect the 1P connector from the horn.
TERMINAL
Test the horn by connecting
termina I and grounding the
horn fails to sound, replace it.
battery power to the
mou nting bolt. lf the

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