2003 HONDA CIVIC switch

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

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

Heating and Air Conditioning
Compressor Clutch Circuit
Troubleshooting (cont'dl
16. Check for continuity between the No. lterminal of
the compressor clutch relav 4P socket and the No. l
terminal of the compressor clutch 1P conneclor.
COMPRESSON CLUTCH RELAY 4P SOCKET
COMPRESSOR CLUTCH 1P CONNECTORTerminal side of male terminals
ls therc continuity?
YES-Check the compressor clutch clearance, the
thermal protector, and the compressor clutch field
coil (see page 21-48).I
NO-Repair open in the wire between the
compressor clutch relay and the compressor
clutch.l
21-32
A/C Pressure Switch Circuit
Troubleshooting
'1. Turn the ignition switch ON {ll).
2. Turn the blower switch on, and check for blower
motor operatron.
Does the blower motor run on all speeds?
YES Go to step 3.
NO Troubleshoot the blower motor circuit (see
page 21-20).
3. Turn the ignition switch OFF.
4. Disconnect heater control panel connectorA ('14P).
5. Turn the ignition switch ON (ll).
6. Measure the voltage between the No, 4 terminal of
heater control panel connector A {14P) and body
grou nd.
HEATER CONTROL PANEL CONNECTOR A (I4P}
1.
ls there battety voltage?
YES Go to step 7.
NO-Go to step 9.
Stan the engine.
Wire side of female termina's

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.
\'
,.,:l'

Heating and Air Gonditioning
a
\
Power Transistor Test
1. Disconnect the 4P connector from the power
Iranslslor.
2, Measure the resistance between the No. 1 and
No. 2 terminals of the power transistor. lt should be
about '1.4 1.5 kQ.
. lf the resistance iswithln the specifications, go to
step 3.. lf the resistance is notwithin the specifications,
replace the power transistor.
POWER TRANSISTOB
Carefully release the lock tab on the No. 4 terminal(BLUI/EL) (A) in the 4P connector, then remove the
terminal and insulate it from body ground.
(To 12 V power source on vehicle)
Reconnect the 4P connector to the power transistor.
Supply 12 volts to the No. 4 cavity with a jumper
wire.
Turn the ignition switch ON (ll), and check that the
blower motor runs.
. lf the blower motor does not run, replace the
power rranstsror.. lf the blower motor runs,the powertransistoris
oK.
12 V power source on vehicle)
21-38
1.
Heater Control Panel and Push
Switch Assembly Removal and
Installation
Remove the center panel (see page 20-62).
Remove the dials (A), then remove the self-tapping
screws and the heater control panel (B)from the
center panel (Cl. Remove the self-tapping screws
and the push switch assembly (D)from the center
panel.
lnstall the control panel and push switch assembly
in the reverse order of removal. After installation,
operate the control panel controls to see whether it
worKs propeny.
Run the self-diagnosis function to confirm that
there are no problems in the system (see page 21-
8).
3.
4.

Heating and Air Conditioning
Heater Valve Cable Adjustment
1. From underthe hood, open the cable clamp {A),
then disconnect the heater valve cable (B) from the
heater valve arm {C).
tFrom under the dash, disconnect the heater valve
cable housing from the cable clamp (A), and
disconnect the heater valve cable (B) from the air
mix control linkage {C).
, t.- l
\'r2t' ''' '
' ::"'
Set the temperature control dial on Max Cool with
the ignition switch ON (ll).
Attach the heater valve cable (B) to the air mix
control linkage (C) as shown above, then snap the
heater valve cable housing into the cable clamp (A).
.'.-:',,
-"ll
.....-
21-46
5, From under the hood, turn the heater valve arm {C)
to the fully closed position as shown, and hold it.
Attach the heater valve cable (B) to the heater valve
arm, and gently pull on the heater valve cable
housing to take up any slack, then install the heater
valve cable housing into the cable clamp (A).
.
\