2003 HONDA CIVIC fuse box

3.
Recirculation Control Motor Circuit Troubleshooting
1. Check the No. 14('10A)fuse inthe under-dashfuse/
relay box.
ls the f use OK?
YES Go to step 2.
NO- Replace the fuse, and recheck.l
2. Disconnect the recirculation control motor 5P
conneclor.
Turn the ignition switch ON (ll).
lvleasure the voltage between the No. 5 terminal of
the recirculation control motor 5P connector and
body ground.
RECIRCULATION CONTROL MOTOR5P CONNECTOR
7.
Wire side of female terminals
ls there battery voltage?
YES Go to step 5.
NO- Repair open in the wire between the No. 14
fuse in the under-dash fuse/relay box and the
recirculation control motor .l
Turn the ignition switch OFF.
Testthe recirculation control motor {see page 21-
36),
ls the recirculation control motor OK?
YES Go to step 7.
NO- Replace the recirculation control motor, or
repair the linkage and doors.I
Disconnect heater control panel connector A (14P).
5.
6.
8. Check for continuity between the No. 5 and No. 6
terminals of heater control panel connector A (14P)
and body ground individually.
HEATER CONTROL PANEL CONNECTOR A I14P)
Wire side of female terminals
ls there continuity?
YES Repair any shortto body ground in the
wire(s) between the heater control panel and the
recirculation control motor.l
NO-Go to step 9.
9. Turn the ignition switch ON (ll), and check the same
wires for voltage.
HEATER CONTROL PANEL CONNECTOR A Il4PI
Wire side of lemale terminals
ls therc any voltage?
YES Repair any shonto power in the wire(s)
between the heater control panel and the
recirculation control motor. This shon may also
damage the heater control panel. Repair the shon
to power before replacing the heater control
pa nel. I
NO-Go to step 10.
{cont d r
21-25

Heater Control Power and Ground Circuits Troubleshooting
1. Check the No.14 (10A)fuse in the under-dash
fuse/relay box.
ls the f use OK?
YES-Go to step 2.
NO-Replace the fuse, and recheck.l
2. Disconnect heater control panel connectorA{'14P).
3. Turn the ignition switch oN (ll).
4. Measure the voltage between the No. l4terminal
of heater control panel connector A (14P) and body
grouno.
HEATER CONTROL PANEL CONNECTOR A {14P}
23456
78I10 l,111214
Wire side of temale terminals
BLK/YEL
ls there battery voltage?
YES-Go to step 5.
NO Repair open in the wire betvveen the No. 14
fuse in the under-dash fuse/relay box and the
heater control panel.l
Turn the ignition switch OFF.
6. Check for continuity between the No. l3terminal of
heater control panel connector A (14P) and body
g rou nd.
HEATER CONTRoL PANEL CONNEcToR A (1ilP)
123456
I89r0 t,1l1214
BLK
.o
Wire side of temaleterminals
ls therc continuity?
YES Check for loose wires or poor connections at
healer control panel connector A (14P). lfthe
connections are good, substitute a known-good
heater control panel, and recheck. lf the symptom/
indication goes away, replace the original heater
control panel.l
NO Check for an open in the wire between the
heater control panel and body ground. lf the wire is
OK, check for poor ground at G501. I
21-27

Heating and Air Conditioning
Condenser Fan Circuit Troubleshooting
NOTE: lf neither the condenser fan nor the radiator fan
work, go to Radiator and Condenser Fans Common
Circuit Troubleshooting (see page 21-29).
1. Check the No. 1 (20A) fuse in the under-hood
fuse/relay box, and the No. 14 (10A)fuse in the
under-dash f use/relay box.
Are the tuses OK?
YES-Go to step 2.
NO Replace the fuse(s), and recheck. t
2. Remove the condenser 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 condenser fan relay.l
3. Measure the voltage between the No, 2 terminal of
the condenser fan relay 4P socket and body ground.
CONDENSER FAN RELAY ilP SOCKET
ls thete battery voltage?
YES-Go to step 4.
NO-Replace the under-hood fuse/relay box.l
21-28
4. Connect the No. landNo.2terminalsof the
condenser fan relay 4P socket with a jumper wire.
CONDENSER FAN RELAY itP SOCKET
JUMPER WIRE
Does the condenser lan tun?
YES-Go to step 5.
NO Go to step 8.
5. Disconnect the jumper wire.
6. Turn the ignition switch ON (ll).
7. Measure the voltage between the No, 3 terminal of
the condenser fan relay 4P socket and body ground.
ls there battery voltage?
YES Replace the under-hood fuse/relay box.t
NO-Repair open in the wire between the No. 14
fuse in the under-dash fuse/relay box and the
condenser fan relay.l
Disconnect the jumper wire.
CONDENSER FAN FELAY 4P SOCKET
r-,_-l
12 |
Flr\----1--rl
IELK/YEL
d,
I

9.
10.
Disconnect the condenser fan 2P connector,
Check for continuity between the No. 1 terminal of
the condenser fan relay 4P socket and the No. 2
terminal of the condenser fan 2P connector.
CONDENSER FAN RELAY 4P SOCKET
CONDENSER FAN 2P CONNECTORWire side of female terminals
Is there continuity?
YES Go to step 1 1.
NO- Repair open in the wire between the
condenser fan relay and the condenser fan,I
Check for continuity between the No. 1 terminal of
the condenser fan 2P connector and body ground.
CONDENSER FAN 2P CONNECTOR
12
BLK
o
Wire side of {emale terminals
ls there continuity?
YES- Replace the condenser fan motor.I
NO Check for an open in the wire between the
condenser fan and body ground. lf the wire is oK,
check for poor ground at G301.1
'11 .
Radiator and Condenser Fans
Common Circuit Troubleshooting
NOTE; lf both fans and the Ay'C compressor clutch do
not work when the Ay'C switch is on, go to Ay'C Pressure
Switch Circuit Troubleshooting (see page 21-32l, .
1. Check the No. 1 {20A} and No. 4 (20A) fuses in the
under-hood fuse/relay box, and the No. 14 (10A)
fuse in the under-dash fuse/relay box.
Are the tuses OK?
YES Go to steD 2.
NO Replace the fuse(s), and recheck.l
2. Remove the condenser fan relav from the
under-hood f use/relay box.
3. Turn the ignition switch ON (ll;.
4. Measure the voltage between the No. 3 terminal of
the condenser fan relay 4P socket and body ground.
ls there battery voltage?
YES Go to step 5.
NO Repair open in the wire between the No. 14
fuse in the under-dash fuse/relay box and the
radiator fan relay, and the condenser fan relay.l
5. Turn the ignition switch OFF.
6. Reinstall the condenser fan relay.
7. Make sure the IVC switch is OFF.
8. Turn the ignition switch ON (ll).
(cont'd)
CONDENSER FAN RELAY 4P SOCKET
r-,
-l
12lf---r---
l,l,l
lar-vver-
l
o
I
21-29

Heating and Air Conditioning
Radiator and Condenser Fans
Common
(cont'dl
Circuit Troubleshooting
9. Using a Backprobe Set, measure the voltage
between the No. 6 terminal of ECN4 connector B
{24P) and body ground with the ECM connectors
connecteo.
ECM CONNECTOR B {24P}
ls there battery voltage?
YES UDdate the ECM if it does not have the latest
so{tware, or substitute a known-good ECM, then
recheck (see page 11-6). lf the symptom/indication
goes away with a known-good ECM, replace the
original ECM.I
NO Repair open in the wire between the radiator
fan relay, the condenser fan relay and the ECM. t
Wire side of female terminals
21-30
Compressor Clutch Circuit
Troubleshooting
1. Check the No. 1 (20A) fuse in the under-hood
fuse/relay box, and the No. 14 {10A)fuse in the
under-dash fuse/relay box.
Are the tuses OK?
YES Go to step 2.
NO Replace the fuse(s), and recheck.I
2. Check the engine coolant temperature, the throttleposition sensor, and the idle speed (use the Honda
PGM Tester PGM-Fl data list if possible).
ls the coolant temperaturc above nomal, the
throttle position sensor rcading too high, or the
idle speed too low?
YES Troubleshoot and repair the cause of the
high engine coolant temperature, high throttle
position sensor reading, or low idle speed.l
NO-Go to step 3.
3. Remove the compressor clutch relay from the
under-hood fuse/relay box, and test it (see page 22-
51 ).
ls the relay OK?
YES Go to step 4.
NO Replace the compressor clutch relay.I
4. Measure the voltage between the No. 2 terminal of
the compressor clutch relay 4P socket and body
ground.
\
COMPfiESSON CLUTCH BELAY 'P SOCKET
ls there battery voltage?
YES Go to step 5.
NO Replace the under-hood fuse/relay box.I

5. Connect the No. 1 and No. 2 terminals of the
compressor clutch relay 4P socket with a jumper
wire.
COMPRESSOR CLUTCH RELAY 4P SOCKET
JUMPER WIRE
Does the compressor clutch click ?
YES Go to step 6.
NO-Go to step 14.
6. Disconnect the jumper wire.
7. Turn the ignition switch ON (ll).
8. Measure the voltage between the No. 3 terminal of
the compressor clutch relay 4P socket and body
ground.
COMPRESSOR CLUTCH RELAY 4P SOCKET
ls there battery voltage?
YES-Go to step 9.
NO Repair open in the wire between the No.
fuse in the under-dash fuse/relay box and the
compressor clutch relay, I
14
L Turn the ignition switch OFF.
10. Reinstallthe compressor clutch relay.
1 1. l\4ake sure the Ay'C switch is OFF.
12. Turn the ignition switch ON {ll).
13. Uslng the Backprobe Set, measure the voltage
between the No. 18 termina! of ECI\4 connector
E {31P) and body ground with the ECM connectors
connected.
ECM CONNECTOR E 131P}
23t4561E9
141516m21
22232426272931
RED
Wire side of female terminals
ls there battery voltage?
YES Update the ECM if it does not have the latest
software, or substitute a known-good ECM, then
recheck (see page 11-6). lf the symptom/indication
goes away with a known-good ECIM, replace the
original ECM.I
NO Repair open in the wire between the
compressor clutch relay and the ECM.I
14. Disconnect the jumper wire.
15. Disconnect the compressor clutch lPconnector.
{cont'd)
21-31

8. Connect the No.4 terminal ofheatercontrol
connector A (14P) to body ground with a jumper
wire,
HEATER CONTROL PANEL CONNECTOR A I14P}
BLU
23456
78Ir0lx1112l3t4
JUMPER WIBE
Wire side of female terminals
Does the A/C system come on?
YES Replace the heater control panel.!
NO Refer to the multiplex control system (see
page 22-168).1
Using the Backprobe Set, connect the No. 9
terminal of under-dash fuse/relay box connector
F (12P) to body ground with a jumper wire.
UNOER.DASH FUSE/RELAY BOX CONNECTOR F {12P}
9.
25
61B g lrotll2
BLU/WHT
JUMPERWIRE
Wire side of female terminals
Does the NC system come on?
YES Go to step 10.
NO- Refer to the multiplex control system (see
page 22-168).1
NOTE: Check for multiplex codes in mode '1. Follow
the troubleshooting {or any codes found. lf no
codes are found, subsititute a known-9ood
multiplex control unit and a ECM one at a time.
Disconnect the Ay'C pressure switch 2P connector
and under-dash fuse/relay box connector F { 12P).
10.
'13.
21-33
11. Check for continuity between the No. 2 terminal of
the A,/C pressure switch 2P connector and the No. 9
terminal of under-dash fuse relav box connector
F t12Pt.
A/C PRESSURE SWITCH 2PCONNECTORWire side of female terminals
UNDER.OASH FUSE/RELAY BOX CONNECTOR F (12P)
Wire side of fenale lerrrinal'
ls there continuity?
YES Go to step 12.
NO Repair open in the wire between the
under-dash fuse/relay box and the A,,/C pressure
switch.I
Check for continuity between the No. 1 and No. 2
terminals of the A,/C pressure switch.
12.
A/C PRESSURE SWITCH
ls there continuity?
YES Repair open in the wire between the heater
control panel and the A,/C pressure switch.l
NO Go to step 13.
check for proper Ay'C system pressure.
ls the pressure within specitications?
YES Replace the AilC pressure switch.l
NO Repair the AilC pressure problem.I

Heating and Air Conditioning
Air Mix Control Motor Test
1. Disconnect the 5P connector from the air mix
control motor.
2. Connect battery powertothe No. l terminal ofthe
air mix control motor, and ground the No. 2
terminal; the air mix control motor should run, and
stop at Max Cool. lf it doesn't, reverse the
connections;the air mix control motor should run,
and stop at Max Hot. lf the air mix control motor
does not run, remove it. then check the air mix
control linkage and door for smooth movement.
. lf the linkage and door move smoothly, replace
the air mix control motor.. lf the linkage ordoorstickor bind, repairthem as
needed.. lf the air mix control motor runs smoothly, go to
step 3.
AIR MIX CONTROL MOTOR
3.
4.
Measure the resistance between the No. 4 and
No. 5 terminals. lt should be between 2.1 k to
3.9 kQ.
Reconnect the air mix control motor 5P connector,
then turn the ignition switch ON {ll).
Using the Backprobe Set, measure the voltage
between the No. 3 and No. 4 terminals.
Max Cool about 1V
Max Hot about 4 V
lf either the resistance or voltage readings are not
as specified, replace the air mix cotrol motor.
21-34
Air Mix Control Motor Replacement
1.Remove the under-dash fuse/relay box (see page
22-491.
Disconnect the 5P connector {A) from the air mix
control motor (B). Remove the self-tapping screws
and the air mix control motor from the heater unit.
Remove the rod (C) from the arm (D) of the air mix
controi motor.
Install the motor in the reverse order of removal.
After installation, make sure the motor runs
smoothly.
3.
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