2003 HONDA CIVIC heating valve

Do the items in parts A, B, C, D, and E as required for mileage/time interval listed.
AReplace engine oillsee page 8-5i. Capacity without lilter change: 4.0 S (4.2 US qt, 3.5 lmp qt)Rotate tires. Follow the pattern shown in the Owner's Manual Checktire information and condition.
BReplace engine oil filter lsee page 8-6). Capacity with filter change: 4.20 (4.4 US qt, 3.7 lmp qt)Inspect front and rear brakes (see page 19 3i.. Check pads and djscs for wear (thickness), damage, and cracks.' Check calipers tor damage, leaks, and tjghtness ot mount bolts.Check parking brake adjustment. Should be Iully applied within 7 to I clicks.Inspect tie rod ends, steering gearbox, and boots {see page 17 5).. Check rack grease and steering linkage.. Check boots for damage and leaking grease. Chack fluid line {or damage and leaks.lnspect suspension components.. Chock bolts fo r tig htness.. Check condition of ball ioint boots lor deterioration and damage.Inspect driveshaft boots. Check boots for cracks and boot bands for tightness (see page 16-3).Insp€ct brake hoses and lines {including ABS). Checkthe mastercylinder, proponioning control valve, and ABS modulator{or damageand leakage.Check all fluid levels and condition ot tluids; check for leaks. lf necessary, add MTF lsee page 13'3), engioe coolant, brake fluid, and
Lwindshield washer fluid.lnspectexhaust system*. Check catalytic converter heatshield, exhaust pipe and mufflerfordamage,leaks, and tightness {soe page 9,8).lnspect {uel lines and connections*. Check for loose connections, cracks and deterioration; retighten loose connoctions and replacedamaged parts (s€e page 11 146).
InsDect and adiust drive belt.. Look for cracks and damage, and inspect auto tensioner (needs no adjustment).Replace the dust and pollen lilter (see page 21 39).. Replacethe dustand pollen filter whenever airf low lrom the heating and cooling system is lessthan normal.
Replace air cleaner element every 30,000 miles (48,000 km) (independent of time).
l
D
Ei I Replace brake fluid every 3 years (independent oI mileage).
According to state and federal regulations, failure to do the maintenance items marked with asterisk( * ) will not void customer's emissionswarranties. However, Honda recommends that all maintsnance service be done at the recommended interval to ensure long term reliability.
Y
3-5

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

Heating and Air Gonditioning
Component Location Index
SERVICE VALVE{LOW.PRESSUBE SIDEI
EVAPORATOR CORE(Built-in the heater unit)Beplacement, page 21 42
COMPRESSORBeplacement, page 21 47Clutch Check, page 21-48Clutch Overhaul, page 21-49Thermal Protector Check, page 21-48Thermal Protector Replacement, page 21 51Relief Valve Replacement, page 21 51
SERVICE VALVE{HIGH-PRESSURE SIDEI
RECEIVER/DRYER
CONOENSEBReplacement, page 21-52

Heating and Air Gonditioning
System Description (cont'dl
The air conditioning system removes heat from the passenger compartment by circulating refrigerant through the
system as shown below.
/
BLOWER FAN
\
\,u
EXPANSION VALVE(Meters the requiredamount of refrigerantinto the evaporator)
A/C PRESSURE SWITCHWhen the refriqerant is below196 kPa (2.0 kgi/cm',28 psi)or above 3,140 kPa (32 kgf/cm'455 psi), the Py'c pressureswitch opens the circuit tothe Py'C switch and stops theair conditioning to protect thecompressor-
RECEIVER/DRYER(Traps debris, andremoves morsturel
APOBATOR TEMPERATURESENSOR
THERMAL PROTECTOR(Opens the compressor clutch circuitwhen the compressot temperaturebecomes too high)
RELIEF VALVE(Relieves pressure at the compressorwhen the pressure is too high)
A/C COMPRESSOR(Suction and comoression)\-^
I HrcH PRESSURE vAPoR
[ '.... -:--l Low PREsSUBE LrourD
tffi Low PREssURE vAPoR
This vehicle uses HFC-134a (R-'134a) refrigerant which does not contain ch lorofluorocarbons. Pay attention to the
following service items:
. Do not mix refrigerants CFC-12 (R-12) and HFC-134a (R-134a). They are notcompatible.. Use onlythe recommended polyalkyleneglycol (PAG ) refrigera nt oil (KElHlN SP '!0) designedfortheR-134a
compressor. Intermixing the recommended (PAG) refrigerant oil with any other retrigerant oil will result in
compressor failu re.. AllAy'C system parts (compressor, discharge line, suction line, evaporator, condenser, receiver/dryer. expansion
valve, O-rings for joints) have to be designed for refrigerant R 134a. Do not exchange with R-'12 parts.
. Use a halogen gas leak detector designed for refrigerant R-134a.. R-12 and R-134a refrigerant servicing equipment are not interchangeable. Use only a recovery/recycling/charging
station that is U.L.-listed and is certified to meet the requirements of SAE J2210 to service R-134a air conditioning
system.. Always recover the refrigerant R-134a with an approved recovery/recycling/charging station before disconnecting
any Ay'C fifting.
/-
CONDENSER(Radiation of heat)
21-12

Heating and Air Gonditioning
a
1.
Evaporator Core Replacement
Recover the refrigerant with a recovery/recycling/
charging station (see page 21-53).
Remove the bolt, then disconnect the suction line
(A) and the receiver line (B)from the evaporator
core.
6x10mm9.8 N.m (1.0 kgt.m, 7.2lbf.ft)
Remove the blower unit (see page 21-39).
Remove the self-tapping screws and the expansion
valve cover.
21-42
5. Carefully pull out the evaporator core without
bending the pipes.
Installthe core in the reverse order of removal, and
note these items.
. lfyou're installing a new evaporator core, add
refrigerant oil (KElHlN SP-]0) (see page 21-6).. Replace the O-rings with new ones at each fitting,
and apply a thin coat of refrigerant oil before
installing them. Be sure to use the correct O-rings
for HFC-134a (R-'134a) to avoid leakage.. lmmediatelyafter usingthe oil, reinstallthecap
on the container, and seal it to avoid moisture
absorotion.. Do not spill the refrigerant oil on the vehicle; it
may damage the paint. lf the refrigerant oil
contacts the paint, wash it off immediately.. Charge the system (see page 21-55).
6.

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.

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).
.
\

Heating and Air Conditioning
Refrigerant Leak Test
Special Tool Required
Leak detector, Honda Tool and Equipment YGK-H-10PM
commerciallv available
Compressed air mixed with R-134a forms a
combustible vapor.
The vapor can burn or explode causing serious
injury.
Never use compressed air to pressure test
R-134a service equipment or vehicle air
conditioning system.
Air conditioning refrigerant or lubricant vapor
can irritate your eyes, nose, or throat.
Be carefulwhen connecting service equipment.
Do not breathe refrigerant or vapor
Use only service equipment that is U.L.-listed and is
certiified to meet the requirements of SAE J2210 to
remove HFC-134a (R-134a) from the air conditioning
system.
lf accidental system discharge occurs, ventilate the
work area before resuming service.
R-134a service equipment or vehicle air conditioning
systems should not be pressure tested or leak tested
with compressed air.
Additional health and safety information may be
obtained from the refrigerant and lubricant
manufacturers.
21-56
1. Connect a R-134a refrigerant recovery/recycling/
charging station (A) to the high-pressure serviceport (B) and the low-pressure service port (C), as
shown, following the equipment manufacturer's
anstructions.
Open the high pressure valve to charge the system
to the specified capacity, then close the supply
valve, and remove the charging system couplers.
Select the appropriate units of measure for your
refrigerant charging station.
Refrigerant capacity:
500 to 550 g
0.50 to 0.55 kg
1.10 to 1.21 lbs
17.6 to 19.4 oz
Check the system for leaks using a R-134a
refrigerant leak detector with an accuracy of 14 g(0.5 oz) per year or better.
lf you find leaks that require the system to be
opened (to repair or replace hoses, fittings, etc.),
recover the system.
After checking and repairing leaks, evacuate the
system.
3.