2003 HONDA CIVIC Body

Starter Circuit Troubleshooting
NOTE:. Airtemperature must be between 59'and 100'F (15'
and 38'C) during this procedure.
. After this test, or any subsequent repair, reset the
engine controle module (ECM) to clear any diagnostlc
trouble codes (DTCS) {see page 11-4).. The battery must be in good condition and fully
charged.. lf you disconnect the baftery, do the ECM idle learn
procedure (see page 11-139).
Recommended Procedure:. Use a starter system tester.. Connect and operate the equipment in accordance
with the manuf acturer's instructions.
Alternate Procedure
1. Hook up the following equipment:. Ammeter, 0 400 A. Voltmeter, 0 20 V (accurate within 0.1 volt). Tachometer,0 1200 rpm
2.Remove the No. 17 (15A) fuse from the under-dash
fuse/relay box.
With the clutch pedal pressed, turn the ignition
switch to start (lll).
Did the starter crank the engine normally?
YES-The starting system is OK.I
NO-Go to step 4.
3.
L
4-5
4. Check the battery condition. Check electrical
connections at the battery, the negative baftery
cable to body, the engine ground cables and the
starter for looseness and corrosion. Then try
starting the engine again.
Did the statter crank the engine?
YES Repairing the loose connection fixed the
problem. The starting system is now OK.!
NO lf starterwill notcranktheengine atall, goto
step 5. lf it cranks the engine erratically or too
slowly, go to step 7. lf it won't disengage from the
flywheel ring gear when you release the key, check
for the following until you find the cause.
. Solenoid plunger and switch malfunction. Dirty drive gear or damaged overrunning clutch
5. Make sure the transmission is in neutral, then
disconnect the starter subharness 1P connector (A)
from the engine wire harness 'lP connector (B).
Connect a jumper wire from the battery positive
terminal to the starter subharness 'l P connector.
Did the starter crank the engine?
YES-Go to step 6.
NO Check the BLK,ANHT wire between the starter
subharness 1P connector and the starter. lf wire is
OK, remove the starter, and repair or replace as
necessary.
(cont'd)

Starting System
Starter Performance Test
1,Disconnect the wires from the S terminal and the M
termrnal.
Make a connection as described below using as
heavy a wire as possible (preterably equivalent to
the wire used for the vehicle). To avoid damaging
the starter, never leave the battery connected for
more than 10 seconds,
Connect the battery as shown. Be sure to
disconnect the starter motor wire from the solenoid.
lf the starter pinion moves out, it is workingpropefly.
Disconnect the battery from the M terminal. lf thepinion does not retract, the hold-in coil of the
solenoid is working properly.
4-8
L
5. Disconnect the battery from the starter body. lfthepinion retracts immediately, it is working properly.
Clamp the starter firmly in a vise.
Connect the starter to the battery as described in
the diagram below, and confirm that the motor
sta rts and keeps rotating.
6.
7.
lf the eiectric cu rrent and motor speed meet the
specifications when the battery voltage is at 1 1.5 V,
the staner is working properly,
Specifications:
1.1 kw 90 A or less (Electric current),
ot more

'10. Check continuity between the ECM connector
terminal 810 and body ground.
ECM CONNECTOR S I24PI
23 t4 t567
8I10,/1,/315
118,Nnt,/2123
ACGL (WHT/BLUI
t1'
Wire side ol female terminals
ls there continuity?
YES- Repair short to ground in the wire between
the ECM and the engine wire harness 6P connector.
t
NO-Go to alternator and regulator test.
Alternator and Regulator Circuit Test
1. Be sure the battery is sufficiently charged and in
good condition {see page 22-50), and the
connections at the fuse box and alternator are
clean and tight.
2. Raise the hoist to full height.
3. Hook up the ammeter, 0 400 A, to the starter
sub harness.
Lower the hoist.
Hook up the voltmeter, 0 20 V (accurate within
0.1V),toT101.
(cont'd)
4-23

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L
7, Check for continuity between ECM connector
terminal 818 and body ground.
ECM CONNECTOR B {24PI
123 t4 t561
8910,/1,/35
11ont,/2123
ACGC {WHT/GRN}
o
Wire side ot female terminals
9.
ls there continuity?
YES-Repair short to ground in the wire between
the alternator and the ECM.I
NO-Check that the terminals are firmly seated at
the ECM connector B. lf OK, substitute a known-
good ECM, and recheck (see page 11-6).
lf prescribed voltage is now available. replace the
original ECM,I
Turn the headlights and ignition switch OFF.
Disconnect ECM connector B (24P).
10. Check for continuity between ECM connector
terminal 818 and engine wire harness 6P connector
terminal No.2.
ACGC (WHT/GRN)
ECM CONNECTOR B l2,lPI
12314l5lll67
8910t.)15
11on2123
oC (WHT/GRN)
23
56
ENGINE WIRE HARNESS 6P CONNECTOR
Wire side oI lemale terminals
ls therc continuity?
YES Repair or replace the starter subharness or
the alternator (see page 4-30).I
NO Repair open in the wire between the
alternator and the ECM.I
4-25

Cooling System
Radiator and Fans Replacement
1. Drain the engine coolant (see page 10-6).
2. Remove the front bumper {see page 20,85).
3. Remove the bulkhead.
4. Remove the upper radiator hose and lower radiator hose.
DRAIN PLUG
UPPER BADIATOR HOSE
BAOIATOA FANASSEMBLY
{
O.RINGRADIATOR CAP
BADIATOB
LOWERCUSHION
\-
RADIATOR FANswtTcH24Nm{2.1t kgl m. 17lbl hl
LOWER FADIATORHOSE
RESERVETANK
A/C CONDENSERFAN ASSEMBLY
9.8 N m {1.0 kgf m,7.2 lbf ft)CONNECTORSRADIATOB FAN SWITCHCONNECTOB
5. Disconnect the fan motor connectors and radiator fan switch connector, then pull the radiator up and out.
6. Remove the fan shroud assemblies and other parts from the radiator.
7. Installthe radiator in the reverse order of removal. Make sure the upper and lower cushions are set securelV.
8. Install the bulkhead in the reverse order of removal. Apply body paint to the bulkhead mounting bolts.
9. Fill the radiator with engine coolant and bleed the air (see page 10-6).
10-10
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Fan Gontrols
Radiator Fan Circuit Troubleshooting
1. Check the No. 4 (20A) fuse in the under-hood
fuse/relay box, and the No. 14 (10A) fuse in the
under-dash fuse/relay box.
ls the tuse (s) OK?
YES-Go to step 2.
NO- Replace the fuse (s) and recheck.l
2. Remove the radiator fan relay from the under-hood
fuse/relay box, and test it (see page 22-51).
ls the relay OK?
YES Go to step 3.
NO Replace the radiator fan relay. t
3. Measure the voltage between the No. 2 terminal of
the radiator fan relay 4P socket and body ground.
RADIATOR FAN RELAY 4P SOCKET
Terminal side of female terminals
ls there battery voltage?
YES Go to step 4.
NO Replace the under-hood fuse/relay box. I
10-14
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(
4. Connect the No. landNo.2terminalsofthe
radiator fan relay 4P socket with a jumper wire.
RADIATOR FAN RELAY 4P SOCKET
JUMPERWIRE
Terminal side of Iemale terminals
Does the radiatot fan run?
YES Go to step 5.
NO Go to step 6.
Disconnect the jumper, and turn the ignition switch
ON { ll}. Check for voltage between the No. 3
terminal of the radiator fan relay 4P socket and
body ground.
BADIATOB FAN RELAY 4P SOCKET
Termlnal side of female terminals
ls there battety voltage?
YES-Go to step 9.
NO Check for an open in the wire between the
under-hood fuse/relay box and under-dash fuse/
relay box.l
\-

7.
Disconnect the radiator fan motor 2P connector.
Check for continuity between the No. 1 terminal of
the radiator fan relay 4P socket and the No. 2
terminal of the radiator fan motor 2P connector.
RAOIATOR FAN REI-AY 4P SOCKET
Terminal side offemale terminals
RADIATOR FAN MOTOR 2P CONNECTOR
ls thete continuity?
YES-Go to step 8.
NO Repair open in the wire between the under-
hood fuse/relay box and the radiator fan motor 2P
connector terminal No. 2,I
8. Check for continuity between the No, 1terminal of
the radiator fan motor 2P connector and bodv
g rou nd.
RADIATOR F
Wire side of female terminals
ls there continuity?
YES Replace the radiator fan motor.l
NO Check for an open in the wire between
radiator fan motor 2P connector terminal No. 1 and
body ground. lf the wire is OK, check for a poor
ground at G301.1
AN MOTOR 2P CONNECTOR
rftr
T-
Y
9.
10.
Reinstall the radiator fan relay.
Disconnect the radiator fan switch 2P connector.
Connect the No. 1 and No. 2 terminals, of the
radiator fan switch 2P connector with a jumper wire.
RAOIATOR FAN SWITCH2P CONNECTOR
11.
5\- IJUMPERf-; 'fl I wrRE
--
Wire side of female terminals
Does the radiator fan run?
YES- Replace the radiator fan switch.l
NO-Go to step 12.
Remove the jumper wire, and measure the voltage
between the No, 2 terminal of the radiator fan
switch connector and body ground,
RADIATOR FAN SWITCH2P CONNECTOR
ls there battery voltage?
YES Check for an open in the wire between
radiator fan switch 2P connector terminal No. 1 and
body ground. lf the wire is OK, check for a poor
ground at G301.1
NO Repair open in the wire between the radiator
fan switch terminal No. 2 and the under-hood
fuse/relay box.l
10-15

Fan Controls
Radiator Fan Switch Circuit
Troubleshooting (Openl
1. Disconnect the radiator fan switch 2P connector.
2. Turn the ignition switch ON (ll).
3. Measure voltage between the No.2 terminal ofthe
radiator fan switch 2P connector and body ground.
RADIATOR FAN SWITCH 2PCONNECTOR
ls there battety voltage?
YES-Go to step 4.
NO- Repair open in the wire between the radiator
fan switch 2P connector terminal No. 2 and under-
hood fuse/relay box.l
Turn the ignition switch OFF, and check for
continuity between the No. '1 terminal of the
radiator fan switch 2P connector and body ground.
RADIATOB FAN SWITCX 2PCONNECTOR
ls there continuity?
YES Replace the radiator fan switch. t
NO Check for an open in the wire between theradiator fan switch 2P connector terminal No. 1 and
body ground. lf the wire is OK, check for a poor
ground at G301.1
10-16
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Radiator Fan Switch Circuit
Troubleshooting (Short)
NOTE: After troubleshooting, perform the engine
control module (ECM)idle learn procedure (see page
1 1,139).
1. Remove the radiator fan relay from the under-hood
fuse/relay box, and test it (see page 22-51).
ls the relay OK?
YES Go to step 2.
NO Replace the radiator fan relay.I
2. Remove the radiator fan switch, and test it (see
page 10-17 ).
Is the radiatot tan switch OK?
4.
YES Go to step 3.
NO Replace the radiator fan switch.I
Disconnect the battery negative cable from the
battery.
Disconnect engine control module {ECM) connector
B (24P) and the under hood fuse relay box 14P
connector.
Check for continuity between the No. 2 terminal of
the radiator fan switch 2P connector and bodygrouno.
RADIATOR FAN SWITCH2P CONNECTOR
lstnere continuity?
YES Repair short in the wire between the radiator
fan switch 2P connector terminal No. 2 and under-
hood fuse/relay box.l
NO Replace the under-hood fuse/relay box.t
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