Circuit HONDA CIVIC 2003 7.G Workshop Manual

Heating and Air Conditioning
DTC Troubleshooting.(cont'd)
DTC 10: An Open or Short in the Mode
Control Motor Circuit
1. Test the mode control motor (see page 21-35).
ls the mode cottol motor OK?
YES Go to step 2.
NO Replace the mode control motor.I
Disconnect the mode control motor 10P connector.
Disconnect heater control panel connectors A (14P)
and B \22P1.
Check for continuity between body ground and
heater control panel connector A (14P) terminals
No. 2, 10, and 11 individually, and between body
ground and heater control panel connector B (22P)
terminals No. '17, 18, 19, and 20 individually.
HEATER CONTROL PANEL CONNECTOR A {14PI
2.
3.
Wire side ol lemale terminals
ls there continuity?
YES Repair any shortto body ground in the
wire(s) between the heater control panel and the
mode control motor.l
NO Go to step 5.
HEATER CONTROL PANELCONNECTOR B {22P)
Wire side of femaLe lerminals
21-18
5. Turn the ignition switch ON (ll), and check the same
terminals for voltage.
HEATEB CONTROL PANEL CONNECTOR A {14P)
Wire side of female terminal
HEATER CONTROL PANEL CONNECTOR B {22PI
35X6
tl1215T61118t92A2122
RED/YELWHT
Wire side of female terminals
ls there any voltage?
YES-. Repair any short to power in the wire(s)
between the heater control panel and the mode
control motor. This short may also damage the
heater control panel. Repair the short to power
before replacing the heater control panel.l
NO- Go to step 6.

Heating and Air Gonditioning
DTC Troubleshooting {cont'd)
DTC 12: A Problem in the Blower Motor
Circuit
'1. Check the No. 12 (40A)fuse inthe 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.l
2. Connect the No. 2 terminal of the blower motor 2P
connector to body ground with a jumper wire.
BLOWER MOTOB 2P CONNECTOR
JUMPER ] BLU/BLK
Wire side ol female terminals
3. Turn the ignition switch ON (ll).
Does the blowet motor run?
YES Go to step 4,
NO Go to step 17.
4. Turn the ignition switch OFF.
5. Disconnect the jumper wire.
6. Disconnect the power transistor 4P connector.
21-20
8.
7. Check for continuity between the No. 3 terminal of
the power transistor 4P connector and body ground.
POWER TRANSISTOR 4P CONNECTOR
Wire side ol temale terminals
ls there continuity?
YES-Go to step 8.
NO-Check for an open in the wire between the
power transistor and body ground. lf the wire is OK,
check for poor ground at G502.I
Connect the No. 1 and No. 3 terminals of the power
transistor 4P connector with a jumper wire.
POWER TRANSISTOR 4P CONNECTOR
Wire side of female terminals
Turn the ignition switch ON (ll).
Does the blower motor tun at high speed?
YES-Go to step 10.
NO-Repair open in the wire between the power
transistor and the blower motor.l
Turn the ignition switch OFF.
Disconnect lhe jumper wire.
9.
10.
11.
2
34
BLK
o

DTC 14: An Open in the Evaporator
Temperature Sensor Circuit
1. Remove the evaporator temperature sensor (see
page 21-37).
2. Measure the resistance between the No. l and
No. 2 terminals of the evaporator temperature
sensor.x Dip the sensor in ice water, and measure
resistance. Then pour hot water on the sensor, and
check for change in resistance.
EVAPORA
RESISTANCEk0
TOR TEMPERATURE SENSOR
t-lll#l
ll,l,llI UT-TU I---r---T--
t^11c))-l\9/
50 6810 20
TEMPERATURE
ls the tesistance within the specifications shown
on the graph?
YES-Go to step 3.
NO Replace the evaporator temperature
sensor.I
3. Disconnect heater control panel connector B {22P).
86'F30 'c
Terminal side of male terminals
4. Check for continuity between the No. 7 terminal of
heater control panel connector B (22P) and the
No. 1 terminal of the evaporalor temperature
sensor 2P connector.
HEATER CONTROL PANEL CONNECTOR B {22P)Wire side of female terminals
EVAPORATOR TEMPERATURE SENSOR 2P CONNECTORWire side of female terminals
ls there continuity?
YES Go to step 5.
NO Repair open in the wire between the heater
control panel and the evaporator temperature
sensor.I
5. Disconnect heater control panel connector A (14P).
(cont'd)
21-23

Heating and Air Gonditioning
\
DTC Troubleshooting {cont'd)
6. Check for continuity between the No. 2 terminal of
heater control panel connector A (14P) and the
No, 2 terminal of the evaporalor temperature
sensor 2P connector.
HEATER CONTROL PANEL CONNECTOR A {14PIWire side of female terminals
LT GRN
EVAFORATOR TEMPERATURE SENSOR 2P CONNECTORWire side of female terminals
ls there continuity?
YES-Check for loose wires or Door connections at
heater control panel connector A ('l4P) and B l22Pl
and at the evaporator temperature sensor 2P
connector. lf the 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 Reoair ooen in the wire between the heater
control panel and the evaporator temperature
sensor.I
21-24
4.
DTC 15: A Short in the Evaporator
Temperature Sensor Circuit
1. Remove the evaporator temperature sensor (see
page 21-37).
2. Test the evaporator temperature sensor (see page
21-37 J.
ls the resistance within the specifications shown
on the graph?
YES Go to step 3.
NO Replace the evaporator temperature
sensor. !
Disconnect heater control panel connector B l22Pl.
Check for continuity between the No. 7 terminal of
heater control panel connector B {22P) and body
ground.
HEATER CONTROL PANEL CONNECTOR B (22P)
Wire side of female terminals
ls there continuity?
YES Repair short to body ground in the wire
betvveen the heater control panel and the
evaporator temperature sensor. I
NO-Substitute a known-good heater control panel,
and recheck. lf the symptom/indication goes away,
replace the original heater control panel.I

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

Heating and Air Conditioning
Recirculation Control Motor Circuit Troubleshooting (cont'd!
10. Turn the ignition swirch OFF.
11. Check for continuity between the following
terminals of heater control panel connector A ( 14P)
and the recirculation control motor 5P connector.'l4Pt 5P:
No.5 No. 1
No.6 No.2
HEATER CONTROL PANEL CONNECTOR A {14P}Wire side ol temale terminats
RECIRCULATION CONTROL MOTOR 5P CONNECTORWire side ol lemale terminals
ls there continuity?
YES Check for loose wires or poor connections at
heater control panel connector A ( 14P) and at the
recirculation control motor 5P conneclor. lf the
connections are good, substitute a known-good
heater control panel, and recheck. lf the symptom/
indication goes away, replace the original heater
control panel,I
NO Repair any open in the wire{s) between the
heater control panel and the recirculation control
motor.l
21-26

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