2003 HONDA CIVIC Start

Fuse/Relay Boxes
Connector to Fuse/Relay Box Index
Under-hood Fuse/Relay Box
lview of tront sidel
- a-------) | | T---r .-:-tt || tL__.1 | I
------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}
""""-l- tr -l T _l T Il
I tTt Tr,/^-------lFrr^l -/1-l sz- l:!)L' lrt
22-44

Under-dash Fuse/Relay Box
SocketRefTerminal Connects to
B
c
D
E
F
G
H
J
K
M
N
o
P
Power window relay
o
R
S
Starter cut relay
T
Taillight relay
Turn signal/hazard relay
U
W (Memory erase signal (MES)
connector)
X
Y
2
3
1
5
19
9
I
20
24
22
27
26
7
6
10
25
14
18
11
l5
to
17
28
5
6
14
13
12
10
3
:
11'10
1:
.o^
;;
4
8
2
i
nl
al
lt
2
Dashboard wire harness B {see page 22-30)
Dashboard wire harness B {see page 22-30)
Dashboard wire harness B (see page 22-30)
ECM wire harness (see page 22-32)
ECI\4 wire harness (see page 22-32)
Engine compartment wire harness (see page 22-'l8l
Engine compartment wire harness (se e page 22-181
Engine compartment wire harness (see page 22-18)
Engine compartment wire harness (se e page 22-18)
Engine compartment wire harness (see page 22-18)
Dashboard wire harness A (see page 22-26)
Dashboard wire harness A (see page 22-26)
Dashboard wire harness A (see page 22-26)
Dashboard wire harness A (see page 22-26)
Dashboard wire harness A (see page 22-26)
Floor wire harness (see page 22-34)
Floor wire harness (see page 22-34)
ECM wire harness (see page 22-32)
Dashboard wire harness B (see page 22-30)
Multiplex control unit service check connector
Optional connector
Optional connector
Floor wire harness (see page 22-34)
{Plugs directly into the multiplex control(Pluqs directlv into the multiDlex control
unat)
unrl)
I
13
tn--rlI U LI L.] L.Jh--n-UL]L]UL]
I] L] L] LI L]
!3 12
22-45

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

lgnition Switch
Test
SRS components are located in this area. Review the
SRS component locations (see page 23-13) andprecautions and procedures {see page 23-'l4) in the SRS
section before performing repairs or service.
1, Remove the driver's dashboard lower cover {seepage 20-59).
2. Disconnect the 5P connector from the under-dash
fuse/relay box.
WHT/RED
Wire side offemale terminals
BLK/WHTBLK/YEL
BLK/RED
Check for continuity between the terminals in each
switch position according to the table.
Terminal
p.J,i""-\
WHT/RED(ACC)
BLK/WHT YEL(BAT) flGl)
BLK/REDtrc2t
BLK/WHT(sr)
o (LocK)
| (ACC)o---o
[ (oN)
III (START)
c)-_H
o_H
lf the continuity checks do not agree with the table,
replace the steering lock assembly (see page'17-121.
22-53

Gauges
Self-diagnostic Procedure
The gauge assembly has a self-diagnosis function.. The Beeper Drive Circuit Check. The Indicator Drive Circuit ChecL. The LCD Segments Check. The Gauges Drive Circuit Check (Speedometer, Tachometer, Fuel gauge, Coolant temperature gauge). The Communication Line Check (the coolanttemperature signal line between the gauge and ECM)
NOTE: Indicators are also controlled via the communication line.
Entering the self-diagnosis f unction:
Before doing the self-diagnosis function, check the No. 9 (10A) fuse in the under-hood fuse/relay box and No. 10 {7.5A)fuse in the under'dash fuse/relay box.
1. Push and hold the trip/reset button.
2. Turn the lighting switch ON.
3. Turn the ignition switch ON (ll).
4. Within 5 sec., turn the lighting switch OFF, then ON and OFF again.5. Within 5 sec., release the trip/reset button, then push and release the button four times reDeatedlv.
NOTE:. While in the self-diagnosis mode, the dash lights brightness controller operates normally.'Whileintheself-diagnosismode,thetrip/resetbuttonisusedtostartthebeeperdrivecircuitcheckandthegauge
drive cicuit check.. lf the vehicle speed exceeds 1.2 mph 12 km/h) orthe ignition switch is tu rned OFF, the self,diag nosis mode ends.
oN flrl
lgnition
Switch
Lighting
Switch
Trip/Reset
Switch-> Move to selt-diagnosis mode.
5 sec.5 sec.
The Beeper Drive Circuit Check:
When entering the self-diagnosis mode, the beeper sounds five times
The Indicator Drive Circuit Check:
When entering the self-diagnosis mode, the following indicators blink.
Seat belt indicator, Door/hatch indicator, Brake system, Lowfuel indicator, Maintenance required indicator (USA),
Washer fluid level indicator (Canada), Oil pressure light.
v
OFF
22-56

\
The LCD Segment Check:
When entering the self-diagnosis mode, the odo/trip segment blinks five times.
The Gauge Drive Circuit Check:
When entering the self-diagnosis mode, the speedometer, the tachometer, the fuel gauge, and the coolant
temperature gauge needles sweep from the minimum position to maximum position, then return to the minimum
posrtron.
NOTE: After the beeper stops sounding and the needles return to the minimum position, pushing the trip/reset button
starts the beeper drive circuit check (one beep) and the gauge drive circuit check again.
The check cannot be started untilthe needles return to the minimum position.
Self-diagnosismode
Trip/Resetswitch
ON
OFF
ON r-r r-r r-r .-1 r-r r-r
;; lll u u l_l L__l I l-l
5 sec
Faulty:
The needles sweep from theminimum position to themaximum position, then returnto the minimum position-
Normal:
iD
tli-
flOi-
Ending the self-diagnosis function:
Turn the ignition switch OFF.
NOTEr lf the vehicle speed exceeds 1.2 mph {2 km/h), the self diagnosis fu nction ends.
:-l!:!!JlJ!J
,-
t,-- - ,- r- i-
| | | ttfi- r-
9l- r n =--llJL--oFF _---
cause needles Xl" f---U---------l [-----l
Beeper
The Communication Line Check:
In the self-diagnosis mode, after the odo/trip LCD segments check, the self-diagnosis starts the communication line
cnecK.
lf all segments comes on, the communication line is OK.
lf the word "Error" is indicated, there is a malfunction in the communication line between the gauge assembly. the
multiDlex control unit. and the ECM.
@,
22-57

Gauges
2.
3.
Gauge Assembly Replacement
1.Remove the instrument panel (see page 20-59),
then remove the upper column cover {see page 17-
Place a clean shop towel (A) under the gauge
assembly to prevent scratching the steering
colum n or dash panel.
Remove the screws from the gauge assembly (B).
Disconnect the connectors (C), and remove thegauge assemDry.
Installthe gauge assembly in the reverse order of
removal.
Coolant Temperature Gauge
Troubleshooting
Before testing, check the No. I { 10A) fuse in the under-
hood fuse/relay box and the No. '10 (7.5A) fuse in the
under dash fuse/relay box.
1. Start the engine, and check the malfunction
indicator lamp (MlL).
Does the MIL come on?
YES- Troubleshoot the cause of the ECM DTC (see
page 1 1-57), and recheck.
NO-Go to step 2.
2. Check for a multiplex control unit DTC (see page
22,168).
ls a DTC ind icated?
YES Troubleshooting the cause of the multiplex
control unit DTC {see page 22-168), and recheck.
NO Go to step 3.
3. Do the communication line check with the self-
diagnosis procedure (see page 22-56).
ls the word "Error" indicated on the odo/ttip
d isplay ?
YES The gauge cannot receive the signal from the
multiplex control unit and the ECI\,4. Check for an
open in the WHT/GRN wire (gauge connector
terminal B 13). lf no open is found, go to step 5.
NO Go to step 4.
4. Do the gauge drive circuit check with the self-
diagnosis procedure (see page 22-56).
Does the temperature gauge needle sweep lrom
the minimum position to the maximum, then tetutn
to the minimum position?
YES Go to step 5.
NO Replace the gauge assembly.l
5. Substitute a known-good ECM and recheck.
Did the symptom/ ind ication go away?
YES Replace the ECM.
NO Substitute a known good gauge assembly. lf
the symptom/indication goes away, replace thegauge assembly.l
4.
22-64

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