2003 HONDA CIVIC fuse box

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
\-
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
\I
\

Fuel and Emissions Systems
General Troubleshooting Information (cont'dl
How to Reset the ECM
You can reset the ECM in either of two ways:
. Use the OBD ll scantool or Honda PGMTesterto
reset the ECM memory.
See the OBD ll scan tool or Honda PGI\4 Tester user's
manuals for specific instructions.' Turn the ignition switch OFF, and remove the No. 6
ECU {ECM} (15A) fuse (A)from the under-hood fuse/
relav box (Blfor 10 seconds.
How to End a Troubleshooting Session
(required after any troubleshootingl
1. Reset the ECM as described above.
2. Do the ECM idle learn procedure (see page 11-139)
3. Turn the ignition switch OFF.
4. Disconnectthe OBD ll scan tool or Honda PGM
Tester from the DLC.
NOTE: The ECM is part of the immobilizer system.
lf vou replace the ECM, it will have a different
immobilizer code. In order for the engine to start,
you must rewrite the immobilizer code with the
Honda PGM Tester.
11-4
\- ta
J
How to Remove the ECM for Testing
1. Remove the passenger's dashboard lower cover
{see page 20-63), the passenger's kick panel (see
page 20-63), and the glove box (see page 20-63).
2. Remove the ECM mounting bolts (B) and the ECM
(c),
9.8 N.m{1.0 kgf.m,7.2lbt.ft}
3. Remove the ECM (B).
4. Installthe ECM in the reverse order of removal.
L

J/-\-1\_/
BEIAY2
A/C CLUTCH RELAY
RAOIATOR
I
)
T
UNDER.HOODFUSE/RELAY BOX:ONo. 19 BATTERY (8oA)ONo. 6 ECU (ECM) (15A1(3)No.20lG {40A1{Canada:50A}ONo. l4 OPTION {40A1€)No. 9 BACK uP (7.5A1lo)No. 7 HORN, STOP {15A}
UNDER.DASHFUSE/RELAY BOX:ONo. 17 FUEL PUMP{15A}@No. ,t ACG {10A)ONo. 1 IGN COIL (1sA)q)No. 10 METER (7.5A)0)No. 14 A/C CLUTCHRELAY IlOA)@No.2 +B LAF (A/F)HEATER (2OA)
(cont'd)
11-15

""rr"a* JIr''lHr/cnN 1
CONNECTOR E
CONNECTOi K
CONNECTOFJ/GRN
IGNITIONSWITCH
lG2
'I
TESTTACHOMETERCONNECTO8
UNDER.HOOD
UNDER.DASHFUSE/RELAY BOX:
UNDER.DASHFUSE/FELAY BOX
Brake pedal pressed: closedBrake pedal releasedr open
POStTtON SWTTCH
,or"-9J3{51re* _{F "_.rl
4 ACG (1oAt1 tGN CO|L t15A)2 A/F HEATER {2OA)17 FUEL PUMP I15A}1O METER {7.5AI14 A/C CLUTCH RELAY {1OA}
11-45

1 1. Check for continuity between ECM connector
terminal E6 and body ground.
ECM CONNECTOR E {31PI
Wire side o{f Iemale terminals
ls therc continuity?
YES-Repair short in the wire between the ECM
(E6) and the secondary HO2S (Sensor 2).1
NO-Update the ECM if it does not have the latest
soflware, or substitute a known-good ECM, then
recheck (see page 1 1-6). lf the symptom/indication
goes away with a known-good ECM, replace the
original ECM.I
Measure voltage between secondary HO2S
(Sensor 2) 4P connector terminal No. 4 and body
g rou nd.
SECONDARY HO2S {SENSOR 2I 4P CONNECTOR
tFff I
l[faJl--ro'14 | IBLK/OFN)
YI
Terminal side of male terminals
ls there battety voltage?
YES Go to step 13.
NO-Checkthe No. 4 ACG (10A) fuse in the under-
dash fuse/relay box. lf the fuse is OK, repair open in
the wire between the secondary HO2S (Sensor 2)
and No. 4 ACG (10A) fuse.l
13.
14.
t5.
to.
Turn the ignition switch OFF.
Reconnect the secondary HO2S (Sensor 2) 4P
connector.
Disconnect ECM connector E (31P).
Turn the ignition switch ON (ll).
Measure voltage between ECM connector terminal
E6 and A5.
ECM CONNECTORS
A (31 P)
E {31 P}
Wire side ot female terminals
Is there 0-1 V or less?
YES-Repair open in the wire between the ECM
(E6) and the secondary HO2S (Sensor 2). !
NO Update the ECM if it does not have the latest
software, or substitute a known-good ECM, then
recheck (see page 1 1-6). lf the symptom/indication
goes away with a known-good ECM, replace the
original ECM. a
17.
11-69

DTC P0563: ECM Power Source Circuit
U nexpected Voltage
1. Reset the ECI\4 {see page l1-4}.
2. Turn the ignition switch OFF.
3. Wait 5 seconds.
4. Turn the ignition switch ON {lll.
ls DTC P0563 indicated?
YES Go to step 5.
NO-lntermiltent failure, system is OK at this time.
Check for poor connections or loose terminals at
the No. 6 ECU (ECM) {15 A) fuse in the under-hood
fuse/relay box and at the ECM.I
Turn the ignition switch OFF.
Disconnect ECI\4 connector E {31P).
Turn the ignition switch ON (ll).
lvleasure voltage between ECM connector terminal
E7 and body ground.
6.
7.
8.
ECM CONNECTOR E {31P}
Wire side ol remale terminals
ls there battery voltage?
YES Go to step 12.
NO Go to step 9.
MRLY
9.
10.
Remove the glove box (see page 20-63).
Remove the PGM-FI main relay 1 (A7.
Check for continuity between ECM connector
terminal E7 and body ground.
ECM CONNECTOR E 131P)
MRLY{RED/YEL)
Wire side of {emale terminals
ls there continuity?
YES-Repair short in the wire between the ECM
{E7) and the PGM-Fl main relay 1 ,I
NO Replace the PGM-Fl main relay 1.1
Turn the ignition suitch OFF.
Reconnect ECM connector E (31P).
11.
tt.
'13.
(conl'd)
11-81

DTC Pl166: Ay'F Sensor (Sensor 1) Heater
Circuit Malfunction
1. Resetthe ECM (see page 11-4).
2. Start the engine.
ls DTC P1166 indicated?
YES-Go to step 3.
NO-lntermittent failure, system is OK at this lime.
Check for poor connections or loose terminals at
the Ay'F sensor relay, the A,/F sensor (Sensor 1), and
the EcM. !
3. Check the following fuse:
. No. 14 OPTION (30A)fuse in under-hood fuse/
reray Dox.. No. 2*B LAF (Ay'F) HEATER (20A) fuse in under-
dash fuse/relay box.. No. 4 ACG (10A) in underdash fuse/relay box.
Are any of the fuses blown?
YES Repair short in the wire between the Ay'F
sensor relay and the fuses.I
NO Go to step 4.
4. Measure voltage between ECM connector
terminals A1 and A24. 30 seconds after the ignition
switch is turned ON (ll).
ECM CONNECTOR A I31P)
Wire srde of lemale terminals
Is therc battery voltage?
YES-Update the ECM if it does not have the latest
soflware, or substitute a known-good ECM. then
recheck (see page 1 1-6). lf the symptom/indication
goes away with a known-good ECM, replace the
original ECM.I
NO-Go to step 5.
5. Measure voltage between ECM connector
terminals A22 and A24.
ECM CONNECTOR A {31P}
Wire side of female terminals
ls there battery voltage?
YES Go to step 6.
NO-Go to step 10.
6. Turn the ignition switch OFF.
7. Disconnect ECM connector E (31P).
8. Turn the ignition switch ON {ll).
(cont'd)
11-89

DTC Pl298: ELD Circuit High Voltage
1. Resetthe ECM (see page 11-4)
2. Stan the engine.
3. Turn on the headlights.
ls DTC P1298 indicated?
YES-Go to step 4.
NO- Intermittent failure. system is OK at this time.
Check for poor connections or loose terminals at
the ELD and at the ECM.I
4. Turn the ignition switch and headlights OFF.
5. Disconnectthe ELD 3P connector.
6. Turn the ignition switch ON (ll).
7. Measure voltage between body ground and ELD 3P
connector terminal No. 1.
ELD 3P CONNECTOR
IG1 IBLK/ORNI
Wire side ot {emale terminals
ls there battery voltage?
YES-Go to step 8.
NO-Checkthe No. 4 ACG (10A)fuse in the under-
dash fuse/relay box. lf the fuse is OK, repair open in
the wire between the No. 4 ACG (10A) fuse and the
ELD.I
8.
9.
10.
11.
Turn the ignition switch OFF.
Connect ELD 3P connector terminal No. 3 to body
ground with a jumper wire.
Disconnect ECM connector E (31P).
Check for continuity between body ground and
ECM connector terminal E15.
ECM CONNECTOR E 131PI
1 21345ot/II
14LC6l/ 182C21
22123 2421 ./2Q30J
ELDIGRN/RED)i1'
Wire side of female terminals
Is thete continuity?
YES-Go to step 12.
NO Repair open in the wire between the ECM
(E15) and the ELD.
(cont'd)
ELD 3P CONNECTOR
---F-------
l1l2 :rlELD(GRN/RED)
IJUMPER wrRE
II
Wire side of temale terminals
11-93