2003 HONDA CIVIC Circuit

Ground Distribution
Ground to Components Index
GroundComponent or circuit qrounded
Batterv, Transmission housinq
E ngine
G 101ECM (PG is BLK; LG is BRN/YEL)
BLK: IAC valve, lgnition coils, Vehicle speed sensor, VTEC solenoid valve
BRNA/EL: Camshaft oosition (CMP) sensor. CKP sensor, TDC sensor. VTEC oil pressure switch
G 15']EPS control unit
G201ELD unit. Multiplex control inspection connector, Multiplex control unit, Power window relay, Rear
window washer motor, Right front parking light, Right front side marker light, Right front turn signal
light, Turn signal/hazard relay, Washer fluid level sensor (Canada) , Windshield washer motor,
Windshield wiDer motor
G202ABS modulator-control unit
G301
G401
Blower motor relay, Brake fluid level switch, Condensor fan motor, Cruise control actuator, Left front
parking light, Left front side marker light, Left front turn signal light, Radiator fan motor, Radiator fan
swrtcn
Combination liqht switch, lqnitlon kev srvitch, Wiper/wasfrer sr,virch
G402Left and riqht airbaq sensors, SRS unit
G 451Data link connector (DLC)
G501Clutch interlock switchm Clutch pedal position switch (for cruise control), Cruise control main switch,
Cruise control unit, Daytime running lights control unit (Canada), Driver's door lock knob switch,
Driver's door lock switch, Driver's power window motor, Heater control panel, Left power mirror
defogger (Canada), left side turn signal light, Moonroof control unit, Monroof open and close relays,
Moonroof position sensor '1, Moonroof seitch, Power mirror switch, Power transistor, Power window
master switch. SDotliqhts
G502Accessory power socket, Gauge assembly, Keyless receiver unit, lvlultiplex control unit, Right power
mirror defogger {Canada)
G503Audio unit
G551Driver's seat belt switch, Fuel gauge sending unit, Fuel pump, Memory erase signal (IMES) connector,
OPDS unit. Rioht seat belt switch
G552High mount brake light, License plate lights, Rear window defogger, Rear window defogger noise
condenser. Rear window wioer motor, Hatch latch switch
Back-up lights, Brake lights, Rear side marker lights, Rear turn signal lights, Rear window wiper noise
condenser, Rear window wiper intermittent control unit, Taillights
22-48

Battery
{Battery Test
Use either a JCI or Bear ARBST tester, and follow the
manufacturer's procedures. lf Vou don't have one of
these computerized testers, follow this conventional
test procedure:
1. Be sure the temperature of the electrolyte is
between 70'F (21"C) and 100'F (38'C).
2. Inspect the battery case for cracks or leaks.
. lf thecase isdamaged, replacethe battery.l. lf the case looks OK, go to step 3.
3. Check the indicator EYE.
. lf the EYE indicatesthe baftery ischarged, goto
step 4.. lf the EYE indicatesa lowcharge, gotostep7.
4. Apply a 300 amp load for 15 seconds to remove the
surface charge.
5, Wait 15 seconds, then apply a test load of 280 amps
for 15 seconds.
6. Record battery voltage.
. lf voltage is above9.6volts,the battery isOK.l. lf voltage is below9.6volts, gotostepT.
7. Charge the battery on High (40 amps) until theEYE
shows the battery is charged, plus an additional 30
minutes. lf the battery charge is very low, it may be
necessary to bypass the charger's polarity
protection circuitry.
. lf the EYE indicatesthe battery is chargedwithin
3 hours, the battery is OK.l. lf the EYE indicatesthe battery is notcharged
within 3 hours, replace the battery.l
A battery can explode if you do not follow the
proper procedure, causing serious injury to anyone
nearby. Follow all procedures carefully and keep
sparks and open flames away from the battery.
22-50

CONNECTOR A(bluelCONNECTOR BlgreenJ
SPEEDOMETERVehicle Speed Signal CircuitTroubleshooting, page 22-65
TACHOMETEB
FUEL GAUGETest, page 11-156
\7
t----/ \
i.._-
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ODO/TRIP METER
22-55

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.
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t,-- - ,- r- i-
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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
Circuit Diagram
' No20ioAl :USA
ECM/PCM
V
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I ii-ciorurnnI 8| coNNECron
Norll0AlFUSE
UflOEN fiOOO FUSE/8ILAY 8OX
COOLANITEMPfNAIUFTSPIEDOMEIEN TACHOMEIIR FUTLGAUGI GAUGE
8L(
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22-58

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Gauges
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No2il5AlFUSEilnlh.undi hooq DASHllu!./rcl.ybox r LGHTS
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Circuit Diagram (cont'dl
ls?2IBLUIYEL
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cSutsEm n0L
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WASHEFItut0I!VEL6t0tc ToRUGHT(tDl
22-60

Gauges
\"Circuit Diagram (cont'dl
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GRNIfiED
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VLEFTTUNSIGI'IALII'{DICATORGAUGIASSEi|BLY LTCHTS
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22-62
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