heater HONDA CIVIC 2003 7.G Repair Manual

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'

Mode Control Motor Test
Disconnect the 10P connector from the mode
control motor.
Connect battery power to the No. 1 terminal of the
mode control motor, and ground the No. 2
terminal; the mode control motor should run
smoothly and stop at Defrost. lf it doesn't, reverse
the connections; the mode control motor should
run smoothly and stop at Vent. When the mode
control motor stops running, disconnect battery
power immediately.
'1.
4.
MODE CONTROL MOTOR
3. lfthe mode control motor does not run in step 2,
remove it, then check the mode control linkage and
doors for smooth movement.
. lf the linkage and doors move smoothly. replace
the mode control motor.. lf the linkage ordoorsstick or bind, repairthem
as neeoeo.. lfthe mode control motor runs smoothly, go to
step 4.
Use a digital multimeter with an output of 1 mA or
less at the 20 k Q range. With the mode control
motor running as in step 2, check for continuity
between the No. 4,5,6,7,8, and 9 terminals and
the No. 10 terminal individually. There should be
continuity for a moment at each terminal as the
motor moves past each mode position.
lf there is no continuity for a moment at each
terminal. replace the mode control motor.
Mode Control Motor Replacement
2.
3.
1.Remove the ECM (see page 11-4).
Remove the relay mount bracket bolt, and move
the relays out of the way.
Disconnect the 10P connector {A) from the mode
control motor (B). Remove the self-tapping screws
and the mode control motor from the heater unit.
lnstallthe motor in the reverse order of removal.
lvlake sure the pin on the linkage is properly
engaged with the motor. After installation. make
sure the motor runs smoothly.
4.
21-35

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.

Heater Unit/Core Replacement
SRS components are located in this area. Review the
SRS component locations (see page 23'13), and
precautions and procedures (see page 23-14) in the SRS
section before performing repairs or service.
1. Make sure you have the anti-theft code forthe radio,
then write down the freouencies for the radio's
Dreset buttons.
4.
Disconnect the negative cable from the battery,
Disconnect the suction and receiver lines from the
evaporator core (see page 21-42).
From under the hood, open the cable clamp (A),
then disconnect the heater valve cable (B) from the
heater valve arm (C). Turn the heater valve arm to
the fully opened position as shown
When the engine is cool, drain the engine coolant
from the radiator (see page 10-6).
6. Slide the hose clamps (A) back, the n d isconnect the
inlet heater hose (B) and the outlet heater hose (C)
from the heater core. Engine coolant will run out
when the hoses are disconnected; drain it into a
clean drip pan. Be sure not to let coolant spill on
the electrical parts or the painted surfaces. lf any
coolant spills, rinse it off immediately.
Remove the bolt and the heater valve, then remove
the mounting nut from the heater unit. Take care
not to damage or bend the fuel lines and the brake
lines, etc.
7.
8 x 1.25 mm12 N.m (1.2 kgf.m,8.7lbf.ft)
(cont'd)
21-43

Heating and Air Conditioning
Heater Unit/Core Replacement (cont'd)
8. Remove the dashboard {see page 20-66).
9. Disconnectthe connectors (A) from the blower
motor, the recirculation control motor, the mode
control motor, and the power transistor, then
remove the wire harness clips (B) and the
connector (C). Remove the self-tapping screws and
the bracket (D).
Disconnect the connectors (A) from the evaporator
temperature sensor and the air mix control motor,
then remove the wire harness clips (B) and the
connector (C). Remove the self-tapping screw and
the cover (D). Disconnect the heater valve cable (E).
10,
7t,
21-44
11. Remove the mounting bolts, the mounting nuts,
and the heater unit.
Remove the self-tapping screws and the expansion
valve cover (A). Carefully pull out the evaporator
core (B) so you don't bend the inlet and outlet pipes.
Remove the grommet (C), then remove the self-
tapping screws and the flange cover (D). Bemove
the self-tapping screws and the pipe cover (E), then
carefully pull out the heater core (F) so you don't
bend the inlet and outlet oioes.
@
5x 1.0 mm9.8 N.m11.0 kgl m,7.2 tbf.ftl
12.

13. Installthe heater core and the evaporator core in
the reverse order of removal.
14. Installthe heater unit in the reverse order of
removal, and note these items:
. Do not interchange the inlet and outlet heater
hoses, and installthe hose clamps securely.. Refillthe cooling system with engine coolant (see
page 10-6).. Adjust the heater valve cable (see page 2'l-461.. Make sure that there is no coolant leakage.. Make sure that there is no air leakage.. Refer to evaporator core replacement {see step 6
on page 21-42).. Do the engine control module (ECl\4) idle learn
procedure (see page 11-139).. Enter the anti-theft code for the radio, then enter
the customer's radio station Dresets.
21-45

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).
.
\

Connectors and Harnesses
Dashboard Wire Harness A {Left branchl
Connector or TerminalffiAccessory power socketAudio antennaBrake pedal position switchClutch interlock switchClutch pedal poistion switchCruise control unitCruise main switchDaytime r!nning lights control unitDaytime running lights relayGauge assembly connector AGauge assembly connector BHazard warning switchHeater control panel connector AHeater control panel connector BHVAC push switch assemblyKeyless receiver unitLow beam cut relayOptional security connectorPower mirror switchUnder-dash fuse/relay boxconnector K (see page 22-45)Under'dash fuse/relay box
L {see page 22-45}Underdash fuse/relay boxconnector M lsee page 22'45)Under-dash fuse/relay boxconnector N (see page 22-45)UndeFdash fuse/relay boxconnector O (see page 22-45)UndeFdash fuse/relay boxconnectorY (see page 22 45)c504
c505
c506
c507
c508
c509
c510
22226
3029628
I820111819105327
,I4
12
11
34
1
24
25
2 Under middle of dash2 Under left side of dash4 ] Under left side of dash2 ] Under left srde of dash2 | Under left side of dash14 I Under left side of dash5 Under left side of dash14 Under lett side of dash4 Under lett side of dash22 I Behind gauge assembly22 i Behind gauge assembly10 Behind hazard warnning switch22 Behind heater control panel'14 Behind heater control panel10 ] Behind HVAC switch assembly5 I Under middle of dash5 lUnderleftsideofdash16 Under lefr side of dash13 Under left side oI dash17 ln the under-dash fuse/relay box
CanadaCanada
l0In the under-dash fuse/relay box
In the undeFdash fuse/relay box
In the underdash fuse/relay box
In the under-dash fuse/relay box
In the under-dash fuse/relay box
Under left side of dash
Under left side ot dash
Under left side of dash
Under left side of dash
Under middle of dash
Under middle of dash
Under middle ol dash
Driver's door wire harness(see page 22'40)Driver's door wire harness(see page 22-40)Left side turo signal lightsuonarnessRoof wire harness (see page22 3AlFloor wire harness {see page22-341Floor wire harness (see page22 34JDashboard wire harness B(see oaoe 22-30)
12
12
G501
G503
1
21
Under gauge assembly
Under left side of dash
Body ground via dashboard
Body ground via dashboard
Left Side Turn Signal Light Sub harness
Connector to Harness Index (cont'd)
L
Connector or TerminalCavitiesLocationConnects toNolesLeft side turn signal lightc506353422Behind left side turn signal lightUnder left side of dashDashboard wire harness A
22-26

Under-dash Fuse/Relay Box
Fuse
Number
AmpsWire ColorComponent(s) or Circuit(s) Protected
115ABLKA/VHTlgnition coils
2204WHT/REDAirlfuel ratio sensor, ECM
310ARED/BLUDaytime running Iights control unit {Canada)10ABLI(ORNAir/fuel ratio sensor relay, Alternator, CMP sensor, Cruise control main
switch, Cruise control unit. ELD unit, Evaporative emission (EVAP) bypass
solenoid valve, Evaporative emission (EVAP)canister purge valve,
Evaporative emission (EVAP) canister vent shut valve, Secondary H02S,
Vehicle speed sensor
5Not used
67.5AYEUGRNMoonroof control unit, Moonroof open and close relay, Power window
relaV
7204GRNMoonroof motor
I7.5AYEUREDAudio unit
910AGRNOPDS unit, Rear window wiper motor, Rear window washer motor, Rear
window wiper intermittent control unit
107.54YELBack-up lights, Cruise indicator light, EPS control unit, Gauge assembly,
Keyless receiver unit, Multiplex control unit, Security control unit
connector (optional)
117.5ABLIVORNABS modulator-control unit
127.5AYEUREDDaytime runnino liohts control unit (Canada)
1310APNKSRS unit't410ABLK/YE LA,,/C compressor clutch relay, Blower motor relay, Condenser fan relay,
Heater control panel, Power mirror actuator, Power mirror defogger(Canada), Radiator fan relay, Rear window defogger relay, Recirculation
control motor1ENot used
loNot used
1715AYE L/B LKECM, Fuel pump
B LK/YE L>H> Unrr
1815AYEUGRNAccessory power socket
197.5AYEUBLKTurn siqnal/hazard relav, Turn siqnal liohts
2030AGRN/BLKMultiplex control unit, Windshield washer motor. Windshield wioer motor21Not used
22204GRN/BLKPassenqer's window motor
2320A.G R N,A/VHTDriver's window motor
24Not used
25Not used
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f at-t
at I
r^,rl fl
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22-47