2000 HONDA CIVIC Valve

Troubleshooting -'96 - 98 Models
Symptom Chart
NOTE;
. Check the engine coolant level. and allow the engine to warm up before troubleshooting.
. Any abnormality must be corrected before continuing the test.
. Because of the precise measurements needed. use a multimeter when testing.
o Before performing any troubleshooting procedures check:- Fuses No. 41 11.5 Al, No. 55 (40 A) in the under-hood fuse/relay box. and No. 17 (7.5 A) in the under-dash fuse/relay
box- Grounds No. G401, G402- Cleanliness and tightness of all connectors
SymptomRomedy
Hot air flow is low.Blower motor runs. but one or more
speeds are inoperative.
Perform the procedures in the flowchart (see page 21-8).
Blower runs properly.Check for the following:. Clogged heater duct. Clogged heater outlet. Incorrect door position
No hot air flow.Blower motor does not run at all,Perform the procedures in the flowchart (see page 21-10).
Blower motor runs.Check for the following:. Clogged heater duct. Clogged blower outlet. Clogged heater valve. Faultv air mix door. Heater valve cable adjustment (see page 21-44). Air mix control cable adiustment (see page 2'l-441. Faulty cooling system thermostat (see section 10). Clogged evaporator (with air conditioning). Frozen evaporator {with air conditioning)
Mode control motor does not run, or one or more modes
are inooerative.
Perform the procedures in the flowchart (see page 21-13).
Recirculation control door does not chanqe between
FRESH and RECIRCULATE.
Perform the procedu.es in the flowchan (see page 21-16).
Both heater and A,/C do not work.Perform the procedures in the flowchart (see page 21-18),
21-6

Heater Unit
Replacement
SRS components are located in this area. Review the
SRS component locations, precautions, and procedures
in the SRS section {24} before performing repairs or ser-
L Disconnect the negative cable from the battery.
2. Frcm under the hood, open the clamp, then discon-
nect the heater valve cable from the heater valve
arm. 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 section 10).
!@ Do not remove the radiator cap when
the engine is hot; the ongine coolant is under pres'
surg and could severely scald you.
CLAMP
HEATER VALVC CABLE
4. Disconnect the heater hoses from the heater unit.
CAUTION: Engine coolant will damage p8int.
Ouickly rinse any spilled engins coolant from painted
su aces,
NOTE: Engine coolant will run out when the hoses
are disconnected; drain it into a clean drip pan.
5. Remove the mounting nut from the heater unit.
NOTE: When removing the mounting nut, take care
not to damage or bend the fuel lines, the brake
lines, etc.
I x 1 .25 mm22 N.m {2.2 kgl.m, 16lblftl
21-39

Heater Control Panel
'95 - 98 modolsi
Remove the driver's dashboard lower cover, the
glove box and the center dashboard lower cover(see section 20).
Disconnect the air mix control cabls from the heater
unit {see page 21-44).
Remove the rear window defogger switch, the hazard
warning switch and the audio unit (see section 23).
Disconnect the connectors from the heater control
panel. Remove the five self-tapping screws and the
center panel together with the heater control panel.
NOTE: The locking tabs are on the bottom of the
connecrors.
Install in the .everse order of removal. Adjust the air
mix control cable and the heater valve cable {seepage 21-44)..
Replacement
1.
Remove the four self-tapping screws and the heater
21-42
1.
'9!, - 00 modols:
Remove the center panel together with the heater
control panel (see section 20).
Remove the self-tapping screws and the heater con-
trol panelfrom the center Danel.
Install in the reverse order of removal. After
tion, operate the heater control panel to see
whether it works properly.
installa-

Temperature Control
Adjustment -'96 - 98 Models
1. From under the hood, disconnect the heater valve
cable from the heater valve.
TERVALVECABLEHEATER VALVE ARM
2.From under the dash, disconnect the air mix control
cable housing from the cable clamp,
AIR MIXCONTROLARM
3.Set the temperature control lever to MAX. COOL.
With the air mix control cable attached to the air
mix control arm, gently pull on the outer cable
housing to fully close the door and to remove any
slack in the cable. Don't pullto hard, or the temper-
ature control lever will move.
Hold the air mix control arm against the stop. then
snap the air mix control cable housing into the
cable clamp.
21-44
6. From under the hood. move the heater valve arm to
the fully closed position. then attach the heater
valve cable to the heater valve arm.
7. Hold the heater valve arm in the closed position,
and gently pull on the heater cable outer housing to
take up any slack. then install the heater valve cable
housing into the cable clamp.
HEATER VALVE ARM

Adjustment -'99 - 00 Models
1. From under the hood, open the cable clamp, then
disconnect the heater valve cable from the heater
valve arm.
From under the dash. disconnect the heater valve
cable housing from the cable clamp, and disconnect
the heater valve cable from the air mix control arm.
HEATER VALVE CABLE
Set the temperature control dial on MAX COOL with
the ignition switch ON {ll).
Attach the heater valve cable to the air mix control
arm as shown above. Hold the end of the heater
valve cable housing against the stop, then snap the
heater valve cable housing into the cable clamp.
HEATER VALVE ARM
5. From under the hood. turn the heater valve arm to
the fullv closed oosition as shown, and hold it,
Attach the heater valve cable to the heater valve
arm, and gently pull on the heater valve cable hous-
ing to take up any slack, then install the heater valve
cable housing into the cable clamp.
HEATER VALVE ARM
21-45

Air Conditioning
Speciaf Tools ......'.....' 22-2
f f f ustrated f ndex ......................... ".......' 22-3
Wiring/Connector Locations'.........'.... 22'4
Description
Outfine ............ .......22-s
Circuit Diagram
'96 - 98 Models ......"..........".......'.... 22-6
'99 Modef """""""' 22-7
Troubleshooting
Symptom Chart ".'......""................. 22-8
Flowcharts
Condenser Fan .........".................,..'. 22-9
Compressor .....""" 22-12
A/C System .........'.22'17
A/C Thermostat
Test ........'.......' """'22'21
Relays
Test ....."'......... ..""'22-21
A/C Service Tips and Precautions ......22-22
A/C System Torque Specifications '...22-23
A/C System Service
Performance Test ... '."......... ".... ....'..22-24
Pressure Test Chart .................. .... "' 22-26
Recovery ...".........," 22-27
Evaporator
Replacement .....",' 22'24
Overhauf .....-.....""' 22'29
Compressor {SANDEN}
Repf acement ......'.' 22-30
fffustrated fndex ......"..................'.... 22'32
Cf utch Inspection ......... "............ ...... 22-33
Clutch Overhau I ........................ ....... 22-34
Thermal Protector Replacement .... 22-36
Relief Valve Replacement ......'..."". 22-36
Compressor (DENSO)
Repfacement ..""',' 22-37
lf lustrated Index ............................... 22-39
Clutch lnspection ............."'...... "'.... 22-40
Cf utch Overhaul .....................'......... 22-41
Ref ief Valve Replacement'..'......"'.. 22-42
A/C Compressor Belt
Adiustment ............22'43
Condenser
Repfacement .......,,22'44
A/C System Service
Evacuation ...,,,.......22-45
Charging '..........--'..22'46
Leak rest """""""'22-46

lllustrated Index
A/C PRESSURE SWITCHWhen the refrigerant pressure is below 200 kPa {2 0 kg7cm',
28 psi) due to ;frigerant leakage or above 3200 kPa (32 kgf/cm''
455 psi) due to refrigerant blockage, the lVC pressure swrtch
SERVICE VALVE
{LOW.PRESSURE SIDE)
EVAPORATORReplacement, page 22-28
Overhaul, page 22 29
Beplacement, Page 22'44
opens lhe circuit to ihe AVC switch and stops the air condilioning
to protect the comPressor'
RECEIVER/DRYER
COMPRESSORSANDENIReplacement, Page 22 30
CIutch Inspection, Page 22 33
Thermal Protector Inspection, page 22 33
Clutch Overhaul, Page 22'34
Thermal Protector Replacement, page 22 36
Refief Vafve Replacemenl, page 22'36
DENSO:Replacement, Page 22-37
Clutch Inspection, Page 22-40
Clutch Overhaul, Page 22_41
Relief Valve Replacement, page 22-42
A/C THERMOSTATTest, page 22 21
22-3

Description
Outline
The air conditioner system removes heat from the passenger compartment by circulating refrigerant through the system
as shown below.
BLOWER FAN
EVAPORATOR(Absorption of heati
EOUALIZING TUBE(Meters pressure andimproves the expansionvalve reaction time)
into the evaporator)CAPILLATY TUBE SENSING BULB
lControls the temPerature of the
ref rigerant leaving the evaporator
by metering the expansion valve)
/\
THERMOSTAT
A/C PRESSURE SWITCH
When the refrigerant is below
200 kPa (2.0 kgtcm',28 Psi)or above 3,200 kPa 132 kgflcm',
455 psi), the Ay'C pressure
switch opens the circuit to
the A,/C switch and stops the
EXPANSION VALVE(Meters the requiredamount of refrigerant
airconditioning to Protect the
compressor.
RECEIVER/DRYER(Traps debris, andremoves morsturel
THERMAL PROTECTOR
{Opens the comPressorclutch circuit when the
compressor temPeraturebecomes too high)
RELIEF VALVE(Relieves pressure at the
compressor when thepressure is too high)
(Radiation of heat)
I
f-r--; I
(Suction and comPression,
HIGH PRESSURE VAPOR
HtGH PRESSUBE LIOUID
LOW PRESSURE LIOUID
This car uses HFC-134a (R-134a) refrigerant which does not contain chlorofluorocarbons Pay attention to the following
service items:
. Do not mix refrigerants CFC-12 (R-12) and HFC-134a (R-134a)' They are not compatible'
. Useonlythe recommended polyalkyieneglycol (PAG) refrigerant oil designedforthe R-134a compressor (SANDEN: SP-
10; DENSO: ND_OIL8). Intermixing ihe re-commended (pAG) refrigerant oil with any other refrigerant oil will result in
compressor failure.
. All A,,ic system parts {compressor, discharge line, suction line, evaporator, condenser, receiver/dryer, expansion valve'
O-rings for joints) have to be proper for refrigerant R- 134a Do not confuse with R-l2 parts'
. Use a halogen gas leak detector designed for refrigerant R-134a
. R-12 and R-134a refrigerant servacing 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 systems'
. Always recover the refrigerant R-134a with an approved recovery/recycling/charging station before disconnecting any
A,/C fitting.
S]
22-5