2000 HONDA CIVIC Horn circuit

Power Door Locks
Component Location Index
NOTE (With keyless entry systeml:
. It the doors unlock or lock with the transmitter, but the LED on the transmitter does not come on, the LED is faulty;
replace the transmitter'
. when vou unlock the doors with the transmitter, the ceiling light (middle position) comes on for 30 seconds. (However,
if the audio unit is not installed, the light does not come on )
. lf any door is open, you cannot lock or unlockthe doors with the transmitter'
. The horn sounds only the first time you press a transmitter button. (Pressing repeatedly does not activate the horn
again.)
o lf vou unlocked the doors with the transmitter, but do not open any of the doors within 30 seconds, the doors relock
automatically.
. The doors do not lock or unlock with the transmitter if the ignition key is inserted in the ignition switch
. lf you press the PANIC button for more than two seconds, the horn sounds for about 30 seconds, and the transm'fer
LED comes on. (The panic mode will not be activated iJ the ignition key is in the ignition switch ) The panic mode is
cancelled by pressing any of the transmitter buttons'
o After replacing the transmitter battery, press the lock and unlock buttons five or six times to activate the transmitter'
Replacement, section 20
FRONT PASSENGER'S DOOR LOCK ACTUATOR
RIGHT REAR DOOR LOCK ACTUATOR
Test, page 23-263
I.IFT REAR DOOR LOCK ACTUATOR
Test, page 23 263Replacement, section 20
LOCK ACTUATORTest, page 23-263Replacement, section 20
ORIVER'S DOOR LOCK SWITCH
Test, page 23'262
DOOR L@XCONTROL UN]TInput Test, page 23 255
23-251
Test, page 23-263Replacement, section 20
AUDIO UNIT(STER€O RADIO TUNER)
{'96 - 98 models)
lHas built-in keylessl
eceiver circuit IReplacement, page 23-189
Input Test, page 23-260
Terminals, page 23-262
KEYLESS DOOR LOCKCONTROL UNIT l'99 - 00 modelsl
Input Test, Page 23-257
l-l
TRANSMITTER99 - 0O transmitter shown;'96 -98 transmifter
also has an OPTION buttonTest, page 23-264Transmitter Programming, page 23_265
Qi,,a/
/----
L(ru
i'.-8,-'l
/'-'6

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

Ground-to-Components I ndex
f.,lONOTE: All ground wires are BLK unless otherwise noted.
GroundPageComponents or Circuit Grounded
Battery (BLKYEL)
Steering pump bracket
t+-rg ITransmission housing
l
G101
(-1)
G101
(-2)
14-2
and
14-3
ano
14-1
Powertrain or engine control module (PG1 and pG2 are BLK: LG1 and LG2 are
BRN/BLK), EGR control solenoid valve (CW, EGR valve and lift sensor (Dt6yS enginewith M,/T), Engine coolant temperature switch, pGM-Fl main relay, power steeringpressure switch (USA), Primary HO2S (D16Y5 engine with l\/,/T), Vehicle speed sensor,VTEC pressure switch (D16Y5/D16Y8 engines), CKF sensor (BRN/BLK), Transmission
control module (CYf) (Pc1 is BLK: LG1 is BRN/BLK)
Shielding betvveen the PCM or ECM and these components (all have BRN/BLK wires):
CKF sensor, TDC/CKP/CYP sensor. Primary and secondary heated oxygen sensors.
Knock sensor (CWDl6YB engine), Mainshaft speed sensor (AiT except CVT),
I Countershaft speed sensor (A/T except CVf)
Shielding between the TCM and these components (CVT) (all have BRN/BLK wires):
Drive pulley speed sensor, Driven pulley speed sensor, Secondary gear shaft
speed sensor
Powertrain or engine control module (PG1 and pG2 are BLK; LG1 and LGz are
BRN/BLK), EGR control solenoid valve (D16Y5 engine), EGR valve (Dt685), Engine
coolant temperature switch, Fuel pressure regulator shut-off solenoid valve (D1685),
PGM-FI main relay, Power steering pressure switch (USA), Vehicle speed sensor, VTECpressure switch (All except D16Y7 engine), CKF sensor (A

except 81642) (BRN/BLK)
Shielding between the PCM or ECM and these components (all have BRN/BLK wires):
CKF sensor, TDC/CKP/CYP sensor, Primary and secondary heated oxygen sensors,
Knock sensor (All except D16Y7 engine), i/ainshaft speed sensor (Arf except CW),
Countershaft speed sensor (A,/T except CVf), Drive pulley speed sensor (CW), Drivenpulley speed sensor (CVT), Secondary gear shaft speed sensor (CVf)
I Badiator fan motor, Right front parking/turn signat tight, Right headtight
G20214-4I Cruise control actuator, Left front parking/turn signal lights, Left headlight, Rear window
I washer motor, Windshield washer motor, Washer fluid level switch (,99-'00 Canada)
G401| +-o
and
14-7
Accessory power socket, Brake fluid level switch, Clutch interlock switch (M/T), Clutchswitch (lillT with cruise/D16Y5 engine with MfD, Combination wiper switch (Z wires),
Cruise control main switch, Cruise control unit, Dash lights brightness controller, Data
link connector, Daytime running lights control unit (Canada), Gauge assembly, Horn('96-'97 models), Integrated control unit, Interlock control unit (ArI), Keyless door lock
control unit ('99-'00 models with keyless), Moonroof close and open relays, Moonroof
switch, Park pin switch (A/r), Power window relay, Rear window defogger relay, Rear
window defogger switch ('96-'98 models), Steering lock, Stereo radio tuner (,96-,98
USA: LX, EX, and HX), Turn signal/hazard relay, Windshield wiper motor.....plus
everything grounded through G402
6-6

Keyless Receiver Unit Troubleshooting
lf a faulty keyless receiver unit has one of the symptoms below, turn to the page listed and follow the
appropriate troubleshooting procedure. lf the symptom seems related to an input problem, or is not covered
by the troubleshooting procedures, do the Input Tests on page 130-6. Refer to the circuit schematic on pages
1 30-2 and 130-3 as needed.
Symptom Index
Keyless Entry Does Not Work In Any Mode
Ceiling Light Does Not Come On When The Doors Are Unlocked
WithTheTransmitter ....
Doors Do Not Unlock Or Lock With The Transmitter . . . .
Horn Does Not Sound With The Transmitter "Beeo" Feature On
Horn Does Not Stop Sounding .......
Input Tests
Page 130-8
Page 130-9
Page 130-1 0
Page 130-11
Page 130-11
Page 130-11
Page 130-6
.1,

a
Horn Does Not Sound In The Panic
Mode Or With The Transmitter "Beep"
Feature On
NOTE: The transmitter has a Beep On/Off feature.
Refer to page 130-4 for how to tum the beep on or
off.
1. Does the horn sound when the HORN button is
oressed?
Yes - Go to the next steD.
No - Repair the horn circuit.
2. Does the transmittor LED come on when any of
the buttons are pressed?
Yes - Go to the next step.
No - Check the transmitter battery then retest.
ll the beep feature still does not work, go
to the next steo.
3. Recheck with a known good transmitter
reprogrammed to the vehicle. Does the system
work properly in all modes?
Yes - Replace and program the transmitter,
then retest. Use the procedure on page
1 30-4 f or transmitter programming.
No - Go to the next step.
4. With the keyless entry harness connector (B)
disconnected from the radio, run a.iumper wire
f rom terminal 16 to ground.
Does the horn sound?
Yes - Reglace the radio.
No - Repair the open in the terminal 16 (GRY)
wire.
\
Horn Does Not Stop Sounding
1. ls the vehicle equipped with the optional security
system?
Yes - Go to the next step.
No - Go to step 3.
Do€s the horn stop sounding when the security
control unit connector is disconnected?
Yes - Replace the security control unit.
No- Go to the next step.
Does the horn stop sounding when the keyless
entry harness connector (B) is disconnected?
Yes - Reolace the radio.
No - Reoair the hom circuit.
130-11

Keyless Receiver Unit Troubleshooting
lf a faulty keyless door lock control unit has one of the symptoms below, turn to the page listed and tollow the
appropriate troubleshooting procedure. lf the symptom seems relatod to an input problem, or is not covered
by the troubleshooting procedures, do the Input Tests on page 130-16. Refer to the circuit schematic on
pages 130-12 and 130-13 as needed.
Symptom Index
Keyless Entry Does Not Work In Any Mode
Ceiling Light Does Not Come On When The Doors Are Unlocked
With TheTransmitter ....
Doors Do Not Unlock Or Lock With The Transmitter . .
Horn Does Not Sound With The Transmitter 'Beep" Feature On .........
Horn Does Not Sound In The Panic Mode ..
HornDoes NotStopSounding ...............
Page 1 30-17
Page 130- 18
Page 130-1 I
Page 130-19
Page 130-19
Page 1 30-19
Page 130-16Input Tests
\.
130-15

Horn Does Not Sound In The Panic
Mode Or With The Transmitter "Beep"
Feature On
NOTE: The transmitter has a Beep On/Ott toature.
Refer to page 130-14 for how lo turn the be€p on or
off.
1. Does the horn sound whon the HORN button is
oressed?
Yes - Go to the next step.
No - Repair the horn circuit.
2. Does the transmitter LED come on when any of
the buttons are Dressed?
Yes - Go to the next steP.
No - Check the transmitter battery, then retest.
lf the beep feature still does not work, go
to the next steo.
3. Recheck with a known good transmitter
reprogrammed to the vehicle. Does the system
work properly in all modes?
Yes - Replace and program the transmitter,
then retest. Use the procadure on pag€
1 30-1 4 for transmitter programming.
No - Go to the neLt siep.
4. With the keyless door lock control unit connector
disconnected, run a iumper wire from terminal
15 to ground.
Does the horn sound?
Yes - Replace the keyless door lock control unit.
No - Repair the open in th€ terminal 15 (GRY)
wire.
\lr
130.19
Horn Does Not Stop Sounding
1. ls the vehicle equipped with the optional security
system?
Yes - Go to the next step.
No - Go to steD 3.
Does the horn stop sounding when the security
control unit connoctor is disconnected?
Yes - Replace the sEcurity control unit.
No - Go to the nsxt step.
Does the horn stop sounding when the keyless
door lock control unit connector is disconnected?
Yes - Replace the keyless door lock control unit.
No - ReDair the horn circuit.

How the Circuit Works
Arming the Security System
The security system can be armed:
r By pressing the remote control LOCK button
(if equipped)
. 20 seconds atter closing all doors (C)UDX only)
Arming with the Transmitter
The security system can be armed by removing the
ignition key from the ignition switch, closing all
doors and the trunk, and pressing the LOCK button
on the transmitter. When you arm the system in this
way, the remote control LED comes on, the status
LED flashes once per second, the parking lights
flash once. the doors lock. and the horn sounds
once if the beeo sound mode is on.
Passive Arming (CX and Dx only)
When you turn the ignition to OFF, remove the
ignition key from the ignition switch, and close all
the doors and the trunk; the system will
automatically arm itself 20 seconds after the trunk
or last door is closed. When you arm the system
this way, the status LED tlashes 4 times per second
during the exit delay time, and once per second
after the system is armed; the parking lights will
flash once to confirm that the system is armed.
Triggering the Alarm
Atter you've armed the system, it will trigger the
alarm if any door or the trunldhatch is opened. lf the
battery is disconnected when the system is armed or
in the alarm mode, reconnecting it will immediately
trigger the alarm. When the alarm is triggered, the
following will occur for 30 seconds:
. the horn sounds
o the parking lights flash once per second
. the status LED flashes hvice oer second
. the starter is disabled
After 30 seconds, the alarm will stop and the
system will rearm. Pressing the transmitter
UNLOCK button will disarm the svstem.
tlr
133-13
Disarming the System without the Remote
Transmitter (HX, LX, and EX)
You can disarm the system by turning the ignition
switch to ON (ll) and pressing the disarm/valet
switch on the right side ol the stereo tuner face. The
disarm switch will also disarm the svstem after the
system has been triggered.
Disarming the System with the Remote
Transmitter (Hx, Lx, Ex, DX-V, and Si)
Pressing the transmitter UNLOCK button will disarm
the system. The parking lights llash t\ivice if the
alarm has not been tnggered. The parking lights
flash three times if the alarm has been triggered.
The driver's door will unlock. lf you press the unlock
button twice, it will unlock all doors. lf a door is not
opened within 30 seconds, the system will lock all
doors and rearm.
Disarming the System (CX and DX only)
lf the system arms itself, there is a 20 second delay
after you open a door before the alarm will trigger.
To disarm the system in this mode, simply turn the
ignition switch to the ON position
ldentitying Tripped Sensors
The system identifies which sensor trips the alarm
by flashing the status LED. To display the trip
sensor flash code, press the disarm/valet switch 3
times within 5 seconds after the system has been
disarmed. The status sensor will blink according to
the followino codes:
SensorsNumber of Flashes
Door
TrunldHatch
System Switches
1 blink, pause, repeat
2 blinks, pause, repeat
3 blinks, pause, repeat
For further operating instructions, see the security
syslem owner's manual.
(cont'd)