2003 HONDA CIVIC heater removal

21-2
z t-'5
z t-o
z t-o
21-8
21-9
21-10
21-11
21-14
z t- to
HVAC (Heating, Ventilation, and Air Gonditioningl
Heating and Air Conditioning
SpecialTools
Comoonent Location lndex ........
A/C Service Tios and
Precautions
A,/C Refrigerant Oil
ReDlacement
General Troubleshooting
lnformation
DTC Troubleshooting Index .......
Symptom Troubleshooting
1ndex..............
System Description .....................
Circuit Diagram
DTC Troubleshooting ..................
Recirculation Control Motor
CircuitTroubleshooting .......... 21-25
Heater Control Power and Ground
Circuits Troubleshooting ........ 21-27
Condenser Fan Circuit
Troubleshooting ...................... 21-28
Radiator and Condenser Fans
Common Circuit
Troubfeshooting ...................... 21-29
Compressor Clutch Circuit
Troubleshooting ...................... 21-30
A,/C Pressure Switch Circuit
Troubleshooting ...................... 21-32
Air Mix Control Motor
Test and Reolacement ............. 21-34
Mode Control Motor
Test and Replacement ............. 21-35
Recirculation Control Motor
Test and Reolacement ............. 21-36
Evaporator Temperature Sensor
Reolacement and Test ............. 21-31
Power Transistor Test ................. 21 -38
Heater Control Panel and
Push Switch Assemblv
Removal and Installation ........ 21-38
Dust and Pollen Filter
Reolacement ..21-39
Blower Unit Removal and
lnstallation ...... 21-39
Blower Unit Comoonents
ReDlacement ............................ 21-41
Evaporator Core
Reolacement ..21-42*Heater Unit/Core
ReDlacement ..21-43
Heater Valve Cable
Adjustment .....21-46
CompressorReplacement .......... 21-47
Comoressor Clutch Check .......... 21-48
Comoressor Clutch Overhaul ..... 21-49
Compressor Thermal Protector
Reo1acement ............................ 21-51
Comoressor Relief Valve
Reolacement ............................ 21-51
Condenser Reolacement ............ 21-52
Refrigerant Recovery .................. 21-53
System Evacuation ...................... 21-54
System CharginS ......................... 21-55
Refrigerant LeakTest .................. 21-56
A,/C Svstem Tests ........................ 21-57

HEATER UNIT/COREBeplacement, page 21-43
BLOWEN UNITRemoval and Installation, page 21-39
HEATER VALVE CABLEAdjustment, page 21-46
BLOWER UNIT COMPONENTSReplacement, page 21-41
DUSTAND POLLENFILTERReplacement, page 21'39
RECIRCULATION CONTROL MOTORTest, page 21-36Replacement, page 21-36
MODE CONTROL MOTORTest, page 21-35Replacement, page 21-35
AIR MIX CONTROL MOTORTest, page 21'34Replacement, page 21'34
POWER TRANSISTORTest, page 21-38
HEATER CONTROL PANELRemovaland Installation, page 21 38
PUSH SWITCH ASSEMBLYRemoval and Installation, page 21'38EVAPORATOR TEMPERATURESENSORReplacement, page 21-37Test, page 21-37
21-5

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.

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

Audio System
Audio Unit Removal/lnstallation
NOTE:. Put on gloves to protect your hands.. Take care not to scratch the dashboard and relatedpa rts.
1. Make sure you have the anti-theft code for the radio,
then write down the frequencies for the radio's
preset buttons.
2. Remove the driver's dashboard lower cover (see
page 20-59).
3. Remove the two mounting bolts, then pull out the
center panel (A).
4.Disconnect the audio connector (B) and antenna
lead (C), heater control panel connectors (D) and
HAVC push switch assembly (E), then remove the
center panel.
22-100
!\,
7.
Remove the heater control panel (see page 21 38).
Remove the four mounting bolts and the audio unit
from the radio brackets.
Installthe audio unit in the reverse order of
removal, and note these items:
. Make sure the audio unit and A/C connectors areplugged in properly, and the antenna lead is
connected properly.. Enter the anti-theft code for the radio, then enter
the customer's radio station presets.
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I

)
Orive BehInspecaron................ 4-26
Door PanelsRemoval/lnstallation -............................. 20-4
Door Sash TrimRep1acement......................................... 20 10
Door StrikersAdiustment ........................................... 20-13
Door Weatherst psBeplacement...........-............................. 20 1 1
EPS Conirol UnitRemoval/1nsta11ation ..................-......... 17-67
EPS Indicator CircuitTroubleshooting ................................... 17 -47
EPS MotorRemoval/lnstallation .-.......................... 17-49
EVAP CanisterRep1acement......................... ......... 11,189
EVAP Control Syst€mComponentLocation Index ..............'11-170
EVAP Two-Wey ValveTest ..........-.............-............................ 11 186
Evaporetor CoreRep1acement........................ . ... 21-42
Evaporator Tomperature SensorReplacement......................................... 21 -37Test..................................... ..........2137
EvaporrtoFHeater UnitReplacement........................................ 21 43
Exhaust ManifoldRemoval/1nsta11ation ................................ I 7
Exhaust Pipe8ep|acement............................................. 9-8
Front SpeakersRep|acement....................................... 22-102
Front SuspensionComponentLocation Index................... 18-3
Fueland EmissionsDescription ........................................... 11-12
Fuel Fill DoorAdjustment ..........-................................ 20 93
Fuel Fill Door OpenetBeplacement........................ . ............ 20.109
Fuel Fill Door Opener CableReplacement....................................... 20- lO7
Fuel FilterReplacement....................................... 1 1-152
Fuel Gauge Sending UnitTest ......................-.-..........-.................. 11'156
Fuel Injection Syslem (PGM"FIlComponent Location 1ndex................. 11-49
Fuel IniectorsRep1acemen1....................................... 1 1 1 1 l
Fuel Lines and HosesInspection .......................................... 1 1'146Removal ....................... . .. . .... 11-149Insta|1ation .......................................... 1 1 150
FuelPipe ProtectolReplacement....................................... 20-104
Fuel Pressure RegulatotReplacement....................................... 1 1-152
Fuel Pulsation DamperReplacemenl................................... 11 154
Fuel PumpReplacement,,,,,.,.,.,,,.,,,,,,,,,,,,.,.,.,,,..,.. 11-153
Fuel Pump CircuitTroubleshooting -.......-....................... 1 1-141
FuelSupply SystemComponent Location lndex .............. 11 140Adjustment................................... 11-144Test........-...-................. ... ............- 11-145
FuelTankBeplacemenl.............. . ..... .. 11 155
Fuel Tank Vapor ControlValveTest ......................-....... ... . . 11-187Replacement,,.,,...,.,,,.,.,,,,... .. .. 11 189
Fuses{See first page ofthis Index)
)
Rep|acement................. ..................... 4 26
Drive Belt Auto-tensionellnspection ............................................... 4 21Rep1acement.................................... ..4-28
Driver's PocketRemoval/lnstallation -........................... 20-60
Driver's TrayRemoval/lnstallation .........................-.- 20-65
DRL {Daytime Running LightslControl Unitlnput Test .................... ........ . . . ......22-16
DTCs(See first page olthis Index)
Dust and Pollen FillerReplacement......................................... 21-39
Dynamic Damper, DriveshaftsReplacement........................................... 16-8
ECT SensorReplacement.,.,,,.,.,,,,,,,,,,,,,,................ 1 1-1 14
El€ctrical Power Steering IEPS)Signal CircuitTroubleshooting ........ ... .. 11-135
EmblemsReplacement......................-................ 20-100
Engine AssemblyRemova1 .................................................... 5 2Installation ............._.................................. 5-9
Engine Block AssemblyComponent Location Inder ..................... 7.3
Engine Block, BareInspect|onRepair
Fan ControlsComponent Location Index................. 10'l 1Circuit Diagram .. ..... . .. . .................. 10 13
Fender Fairing, FrontReplacement...-................................... 20-103
Final Driven Gear. M/TReplacement.... . . ................................ 13-53
FrameRepair Chan............ ... ....................... 20 11 4
Frame StiffenelReplacement......-................................ 20- J'13
Front ConsoleRemoval/lnstallation ............................ 20 5lDisassembJy/Reassemb|y ................... 20 58
Front DoorsComponent Location Index................... 20-2Adiustment ........................................... 20.12
Front Driveshaft AssemblyInspeclion .................... ... ....16 3Remova1...................-...... ... .....16-3Disassembly ............................... .....165Resassemb|y ................................-......... 16-9Insta11arion ........................ ...... ............ l6 17
Front lmpact SensorsRep1acement............................ ...23 125
................7-15................1 11
)
Entry Light Control SystemComponent Location Index ...............-. 22-89Circuit Dia9ram .................................... 22 90
EPS ComponentsComponent Location 1ndex..........-...... 17-!7Description ........................ ...... ..17-24Circuit Diagram11 26(cont'd)