2003 HONDA CIVIC Workshop Manual

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
A/C Service Tips and Precautions
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 systems.
Air conditioning refrigerant or lubricant vapor
can irritate your eyes, nose, or throat.
Be careful when connecting service equipment.
Do not breathe refrigerant or vapor.
The air conditioning system uses HFC-134a (R-134a)
ref rigerant and polyalkyleneglycol (PAG) ref rigerant oil,
which are not compatible with CFC'12 (R-12) refrigerant
and mineral oil. Do not use R-'12 refrigerant or mineral
oil in this system, and do not aftempt to use R 12
servicing equipment; damage to the air conditioning
system or your servicing equipment will result.
Use only service equipment that is U.L.-listed and is
certified to meet the requirements of SAE J2210 to
remove 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.
. Always disconnect the negative cable from the
battery whenever replacing air conditioning parts.
. Keep moisture and dirt out of the system. When
disconnecting any lines, plug or cap the fittings
immediately; don't remove the caps or plugs until
iust be{ore you reconnect each line.' Before connecting any hose or line, apply a few drops
of relrigerant oil to the O-ring.. When tightening or loosening a fitting, use a second
wrench to support the matching fitting.. When discharging the system, use a R-'134a
ref rigerant recovery/recycling/charging station; don't
release refrigerant into the atmosphere.
21-6
A: 130 m0 {4 l/3 tl.oz,4.6 lmp.oz)
],^
A/C Refrigerant Oll Replacement
Recommended PAG oil: KEIHIN SP 10:
. P/N 38897-P l3-A01AH: '120 m0 i4 fl oz). P/N 38899-P13'A01: 40 m0 i1 1/3 fl oz)
Add the recommended refrigerant oil in the amount
listed if you replace any of the following parts.
. To avoid contamination. do not return the oilto the
container once dispensed, and never mix it with other
refrigerant oils.. lmmediately af'ter using the oil, reinstallthe cap on
the container, and seal it to avoid moisture
aosorpron.. Donotspill the refrigerant oil on the vehicle; it may
damage the paint. lf it gets on the paint, wash it off
immediately.
Condenser ...........25 mA \516 tl.oz, 0.9 lmp.oz)
Evaporator ........... 45 m0 (1 113Il.oz, '1.4 lmp.oz)
Line or hose ......... '10 m0 {1/3 fl.oz,0.4 lmp.oz)
Receiver/Dryer .... '10 m0 ('113 fl.oz,0.4 lmp.oz)
Leakage repai r .... 25 m0, 1516 Il oz, 0.9 lmp.oz)
Compressor ......... For compressor replacemenl,
subtract the volume of oil drained
from the removed compressor from
130 m0 (4 1/3fl.oz, 4.6lmp.oz), and
drain the calculated volume of oil
f rom the new compressor: '130 m0
i.4113 fl.oz,4.6 lmp.oz) Volume of
removed compressor = Volume to
drain from new compressor.
NOTE: Even if no oil is drained from
the removed compressor, don't
d rain more than 50 m0 \1 2/3 fl.oz,'1.8 lmp oz)from the new
compressor.
\
REMOVEDCOMPBESSOR
rA
li
\.. rJ
b
I
,lEL.-
"o*t ttu"
NEWCOMPRESSOR
/- a\i tl
r/
\:)-) -/
_ 0L'r:l_
I I I DRAINING_*lH I voLUME

Discharge hose to the compressor {6 x 1.0 mm) : 9.8 N.m {1.0 kgf.m, 7.2 lbl.ft}Discharge hose to the condenser (5 x 1.0 mml : 9.8 N.m {1.0 kgt.m, 7.2 lbf ft)Condenser line to the condenser (6 x 1.0 mm) : 9.8 N.m {1.0 kgf,m, 7.2 lbt.ft}Condenser f ine to the receiver/dryer {6 x 1.0 mm} : 9.8 N.m (1.0 kgt.fi,7.2lbt.ltlReceiver lineAtothe receiver/dryer {6 x 1.0 mm} : 9.8 N.m {1.0 kgf .m. 7.2 lbf .ft}Receiver line A to the receivei line B : 13 N.m (1.3 kgr.m, 9.4 lbf.ft)Receiver line B and the suction line to the evaporator (6 x 1.0 mm) :9.8 N.m 11.0 kgf.m, 7,2 lbf.ft)Suction line to the suction hose : 3l N m {3.2 kgf.m, 23 lbf ftlSuction hose 1o the compressor (6 x 1.0 mm) : 9.8 N.m 11.0 kgf.m. ?.2 lbf.lt)Compressor to the compressor b.acket {8 x 1.25 mm) : 22 N m {2.2 kgt.m, 16 lbf.ft)Compr€ssor bracket to the engine block {10 x 1.25 mm} : ,14 N.m 14.5 kgf.m, 33 lbf.ft)
RECEIVER LINE A
RECEIVER/DRYER
CONDENSER LINE
21-7

Heating and Air Conditioning
General Troubleshooting Information
How to Retrieve a DTC
The heater control panel has a self-diagnosis function. To run the self-diagnosis function, do the following:
1. Turn the fan switch OFF.
2. Pressand holdthe recirculation control switch andthe rear window defoooer switch down.
3. Turn the ignition switch oN {lli.
4. Release both switches. The recirculation indicator and the rear window defogger indicator come on. The
recirculation indicator goes off 3 seconds later and the Ay'C indicator comes on. then the self-diagnosis will begin.
About 10 seconds later, the self-diagnosis will finish and the A,/C indicator goes off.
.lfanytroubleisfound.therecirculationindicatorblinksthediagnostictroublecode(DTC)toindicateafaulty
circuil or comDonent.. lf the system is OK, the recirculation indicator stays off.
atc
@r
RECIRCULATIONCONTROL SWITCH
BECIRCULATIONINDICATOB
/A\
-:@
INOICATOR
REAR WINDOWOEFOGGER INDICATOR
REAR WINDOWDEFOGGER SWITCH
Examole of DTC indication Pattern IDTC 7)
DTC 7
Reseiting the Selt-diagnosis Function
Turn the ignition switch OFF to cancel the self-diagnosis function. After completing repair work, run the self-diagnosis
function aoain to make sure thatthere are no other malfunctions.
Recirculation +indicatot
Recirculation +indicalorgo6s oft----->
21-8

DTC Troubleshooting Index
In case of multiple problems, the recirculation indicator will indicate only the DTC with the least number of blinks.
ln case of an intermittent failure, the heater control panel will store the DTC until the ignition is turned off.
DTC {Recirculation
Indication Blinks)
Detection ltemPage
7An open in the air mix control motor circuit(see paqe 21-16)
8A short ln the air mix control motor circuit(see Daoe 21-'16)
9A problem in the air mix control linkaqe, door, or motor(see paqe 21- 17)
10An open or shon in the mode control motor circuit(see oaqe 21-18)
11A problem in the mode control linkage, doors, or motor(see paqe 21191
12A problem in the blower motor circuit(see paqe 21-20)
13A problem in the EEPROM in the heater control panel;
the control oanel must be reolaced
(see page 21-38)
14An ooen in the evaDorator temDerature sensor circuit(see paqe 21-23)
A short in the evaDoralor temoerature sensor circuit(see oaqe 21-241
21-9

Heating and Air Conditioning
{
a
a
SvmptomDiagnostic procedureAlso check for
Recirculation control doors do not
change between Fresh and Recirculate
Recirculation Control Motor
Circuit Troubleshooting (see page
21 251
Cleanliness and tightness of all
connectors
Both heater and Ay'C do not workHeater Control Power and Ground
Circuits Troubleshooting (see
page 21-27)
Blown fuse No. '14 (10A) in the
under-dash fuse/relay box
Poor ground at G501
Cleanliness and tightness of all
conneclors
Condenser fan does not run at all (but
radiator fan runs with the Ay'C on)
Condenser Fan Circuit
Troubleshooting {see page 21-28)
. Poor ground at G301. Cleanliness and tightness of all
connectors
Both fans do not run with the A,/C onRadiator and Condenser Fans
Common Circuit Troubleshooting
(see page 21-29)
Blown fuse No. 1 (20A) and No.4
(20A) in the under-hood fuse/relay
box
Poor ground at G30l
Cleanliness and tightness of all
connectors
Compressor clutch does not engage(both fans run with A,/C on)
Compressor Clutch Circuit
Troubleshootinq (see Daqe 21-30)
Cleanliness and tightness of all
connectors
A/C system does not come on (both
fans and compressor)
Ay'C Pressure Switch Circuit
Troubleshooting (see page 21-32)
Blown fuse No. 1 (20A) and No. 4
(20A) in the under-hood fuse/relay
box
Poor ground at G301
Cleanliness and tightness of all
connectors
\Symptom Troubleshooting Index
\
21-10
!

System Description
Heater Control Panel Inputs and Outputs
CONNECTOR A {r/rP)
CONNECTOR
CONNECTOR
HEATER CONTFOL PANEL CONNECIORS
CONNECTOR B (22P)
W re s de oitema eterm nals
Cavity Wire color_| \ln YAIR MIX POTENTIAL +5V
Sional
OUTPUT2LT GRNSENSOR COMMON GROUNDINPUT3PNK/BLUAIR MIX HOTOUTPUTBLUA,/C PRESSURE SWITCHINPUT5GRNA/ELRECIRCULATEINPUT6GRNA/VHTFRESHINPUT7BLUI/ELPOWER TRANSISTOROUTPUT8BLU/REDBLOWER FEEDBACKINPUTIGRNAIR MIX COOLOUTPUT10YEL/REDMODE DEFOUTPUT11. YEVBTU
YEL/BLK
MODE VENT
REAR WINDOW DEFOGGER RELAY
OUTPUT
INPUTBLKGROUNDOUTPUT14B LK/YELlG2 (Power)INPUT
Bon
CavityWire colorSiqnal1--T
2
3BLIVREDREAR WINDOW DEFOGGER SWITCH LEDINPUT
4LT GRNA./C SWITCH LEDINPUT
5LT GRN/BLKRECIRCULATION CONTROL SWITCH LEDINPUT
6PNVBLKAIR MIX POTENTIALOUTPUT
7BRNEVAPORATOR TEIMPERATURE SENSOROUTPUT
8
9
10
GAUGE ASSEMBLYal' 'TDr ri11RED
RED/BLKTAILLIGHTS RELAYINPUT
14BLUREAR WINDOW DEFOGGER SWITCHINPUTicLT GRN/REDA/C SWITCHINPUT16YEVREDRECIRCULATION CONTROL SWITCHINPUT17YEUGRNMODE 4OUTPUT18WHT/BLUMODE 3OUTPUT19RED/BLUMODE 2OUTPUT20RED/YELMODE 1OUTPUTBRN^,^/HTIGN (PowedOUTPUT22R E DA/r'HT(Not used)
(cont'd)
21-11

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