2003 HONDA CIVIC Turn signal

Exterior Lights
1.
2.
Taillight Replacement
Remove the rear bumper (see page 20-86).
Open the tailgate, and disconnect the connectors(A) from the taillight (B).
Brako/Taillight; 2115W
Turn Signal Light: 21 W
Back-up Light: 21W
Remove the mounting nuts and bolts, then remove
the taillight.
Turn the bulb socket 45' counterclockwise to
remove the bulb socket.
When installing the taillight. check the gasket; if it is
distorted or stays compressed, replace it.
After installing the taillight. run water over the
taillight to make sure it does not leak.
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22-82
High Mount Brake Light
Replacement
1. Open the hatch.
2. Remove the plastic trim.
3. Disconnectthe 2P connectors (A)from the high
mount brake light (B).
High Mounl Brake Light: 5 W x 5
Carefully remove the high mount brake light.
lnstall the light in the reverse order of removal.5.
'

Exterior Lights
Brake PedalPosition Switch Test
1. Disconnectthe 4P connector (A) from the brakepedal position switch {B).
Check for continuity between the No. 1 and No. 2
termtnals.
. There should be continuity when the brake pedal
rs presseo.
. There should be no continuity when the brake
pedal is released.
Check for continuity between the No. 3 and No. 4
terminals {with cruise control).
There should be no continuity when the brake
pedal is pressed.
There should be continuity when the brake pedal
is released.
lf necessary, adjust or replace the switch, or adjust
the pedal height (see page 19-6).
22-84
Side Turn Signal Light Replacement
NOTE: Be careful nol to damage the fender.
1. Push the retaining spring (A). and remove the side
turn signal light (B),
Side Turn Signal Light: 5 W
2. Disconnect the 2P connector {C) from the light.

Turn Signal/Hazard Flasher
Component Location Index
COMBINATION LIGHT/TURN SIGNAL SWITCHTest, page 22-80Beplacement, page 22-80
TURN SIGNAL INDICATOR LIGHTS(ln the gauge assembly)Bulb Replacement, page 22'63
HAZARD WARNING SWITCHTest, page 22-88Replacement, page 22-88
TURN SIGNAL/HAZARD RELAYInput Test, page 22-87
UNDER.DASH FUSE/RELAY BOX
22-85

Turn Signal/Hazard Flasher
UNDff HOOD FUSUftIIY 8OX
Circuit Diagram\
'No20lr0A USAUt oEB DASH No.2{ l50A) :CmadaTUSVRILAY 8OX
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INDICATONIIGHT11.1W)
fiIGHT T
FBONT
22-86
!

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

Turn Signal/Hazard Flasher
1.
2.
Hazard Warning Switch Test
Remove the center panel (see page 20-62).
Disconnect the 10P connector (A) from the hazard
warning switch (B).
4.
Push out the hazard warning switch from behind
the center panel (C).
Check for continuity between the terminals in each
switch position according to the table.
lf the continuity is not as specified, replace the bulb(D) orthe hazard warning switch.
Termin6l
;;;-_-\124710
OFF
ON@
3.
22-88

System Description
The vehicle is equipped with an immobilizer system that will disable the vehicle unless the proper ignition key is used.This system consists of a transponder located in the ignition key, an immobilizer control unit-receiver, an indicatorlight, and the ECM.
When the key is inserted in the ignition switch and turned to the ON {ll) position, the immobilizer control unit-receiversends power to the transponder in the ignition key. The transponder then sends a coded signal back to the immobilizer
control unit-receiver which then sends a coded signal to the ECI\4.
iEl'JUiliii'tlun"oona"|.r KEYCYLTNDER
lf the proper key has been used, the immobilizer indicator light will come on for about 2 seconds, then go off.lf the wrong key has been used or the code was not received or recognized by the unit, the indicator light will comeon for about 2 seconds, then it will blink until the ignition switch is turned OFF.lf the ignition switch is turned OFF, the indicator will blink for about 5 seconds to signal that the unit has reset
correctly, then the indicator will go off.
lf the customer has lost his key, and cannot start the engine, contact Honda Customer Relations.
IMMOBILIZER INDICATOR LIGHT BLINKING PATTERN:
IGNITION SWITCHON
OFF
PROPER KEYINSERTEDINDICATORLIGHTON
WRONG KEYINSERTEDINDICATORLIGHTON
OFF
(| i.,
IMMOBILIZER CONTROL UNIT.RECEIVER
)
22-163

ISystem Descriptions
The Multiplex Control System has four internal
functions:. Multiplexing (send multiple signals over sharedwtres). Wake up/sleep (runs at full power only on demand toreduce battery draw). Fail-safe (fixes or ignores faulty signals). Self-diagnosis (Mode 1 for the system, Mode 2 for
input lines)
The system controls the function of these circuits:. Entry lightcontrol (ignition key lightandceiting light). Wiper/washer intermittent wipe and park functions. Keyless/power door lock. Meter assembly, temperature gauge, and indicator
lights. HVAC (compressor and fan control). Key-in reminder. Headlight reminder. Seatbelt reminder
JI
/ar
22-171
Multiplex Communication
To reduce the number of wire harnesses, digital signals
are sent via shared multiplex communication linesrather than sending normal electrical signals throughindividual wires.. The input signals from each switch are converted todigital signals at the central processing unit (CpU).. The digital signalsaresentfromthetransmitting unitto the receiving unit as serial signals.. The transmitted signal is converted to a switch signalat the receiving unit, and it operates the related
component or monitors a swltch.. There are exclusive communicalion lines between
the ECM, the gauge assembly, and the under,dash
fuse/relay box.
Wake-up and Sleep
The multiplex control system has "wake-up" and"sleep" functions to decrease parasitic draw on the
battery when the ignition switch is OFF.. ln the sleep mode, the multiplex control unit stops
functioning (communication and CPU control) when it
is not necessary for the system to operate.. As soon as any operation is requested (for example, adoor is unlocked), the related control unit in the sleep
mode immediately wakes up and begins to function.. When the ignition switch is turned OFF, and the
driver's or front passenger's door is opened, then
closed, there is about a 10 second delay before the
control unit goes from the wake-up mode to the sleepmode.. lf any door is open, the sleep mode will not function.. lf a key is in the ignition switch, the sleep mode will
not function.. When in sleep mode, the draw is reduced from
70 80 mA to less than 10 mA.
Fail-safe
To prevent improper operation, the multiplex controlsystem has a fail-safe function. In the fail-safe mode,
the output signal js fixed when any part of the systemmalfunctions (for example a faulty control unit orcommunication line).
Each control unit has a hardware fail-safe function thatfixes the output signal when there is any CPUmalfunction, and a software fail-safe function thatignores the signal from the malfunctioning control unitand allows the system to operate normally.