1999 HONDA CR-V Temperature sensor

Component Location
Index (cont'dl
SRS components are located in this area. Review the SRS component locations, precautions, and procedures in the SRS
section (24) before performing repairs or service.
BECIRCULATION CONTROL MOTOR4P CONNECTOR
EVAPORATOR TEMPERATURE SENSORTesl, page 22-44POWER TRANSISTOR3P CONNECTOR
AIR MIX CONTROL MOTORReplacement, page 22-43lest, page 22-13
BLOWER MOTOB2P CONNECTOR
BLOWER MOTOR HIGH RELAYTest, page 22-45
HEATER SUB.HARNESS
7P CONNECTOR
DASHBOARD WIRE HARNESS
HEATER CONTROL PANEL8P AND 2OP CONNECYORS
22-6
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cnNj@_snN
GRY
PNK/BLK
NED/8LU
REO/YEL
YEL/BLU
8RN/WHT
GRNI/VHT
GRN/RED
POWERTRANSISTOR
c401c402
22-9
4
ORNMHT
Fg"{
EVAPONATORTEMPERATURE SENSOR
fi3'.Hfi|$l#i9D>
"'"-
DASH LTGHTS _/4EE|GHTNESS < l_ REDCONTROLLER -!
REAR
fllf$!S,* (l aLurrLRELAY
O:8P coNNEcToR
n :20P c0NN€CToR
YEL/RED
GRN/YEL
8LU/8LK
BRN
YEL
s5v s coM
AMD P AIR MIXCONTROLMOTOB
HOT
VENT
B/LI/lODEH CONT8OLl
10T0RH/D MDEF
HEATER CONTROL PANEI-
8LK
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Self-diagnosis Function
The heater control panel has a self-diagnosis function.
Running the Self-diagnosis Function'97 mod€l:
Turn the ignition switch ON {ll), then set the mode control dial to the Vent position, and the recirculation controt switch toRecirculate {recirculation indicator light comes on). Press and hold the recirculation control switch to Fresh (recirculation indi-cator light goes off). Continue to hold the switch; the recirculation indicator light will come on for two seconds. then it willblink the Diagnostic Trouble Code (DTC) to indicate a iaulty component. lf no DTC'S are found, the indicator liqht will notblink atter the initial two second light.
'98 - 00 models:
Set the mode control dial to the Vent position, and turn the ignition switch ON (ll). Within six seconds after turning the igni-tion switch on, press the recirculation control switch the required number of times depending on the recirculation indicatorlight status:
.lftheindicatorlightisON,presstherecirculationcontrol switch five times..lftheindicatorlightisOFF,presstherecirculationcontrol switch six I|mes.The recirculation indicator light will come on for two seconds, then blink the Diagnostic Trouble Code (DTC) to indicate afaulty component. lf no DTC'S are found, the indicator light will not blink after the initial two second liqht.
DTC Indicaiion Pattern {See DTC 3}:
Rocirculationindicatorlight on
Recirculrtionindicatorlighi off'97 model:P.ess and hold th6 recircul.tioncontrol switch'98 - 00 modek:Within six second3 atter theignition switch b turned ON (lll.Prass the rocirculation controlswitch the required number oltimes depending on the r6circu-lation indicator light striu3
,r*
/1.5 aaa 0.3 aac
RECIRCULANONINDICATOR LIGHT
In case of multiple problems, the recirculation indicator light indicate only one DTC that is the least number of blinks.
Resetiing the Solf.diagnosis Funqtion
Turning the ignition switch OFF will cancel the self-diagnosis function. After service work, run the self-diaqnosis functiononce again to check that there is no other Droblem.
MODE CONTROL OIAL
Diagnostic
trouble
code {DTCI
R6circulation
indicator lightComponent with problsmPossiblo causcSee page
'lOne blinkAir mix control molorOpen or short circuit, obstructed door,
faulty motor22-12
2Two blinksElower motorOpen or short circuit, faultv motor22-14,16
Three blinksEvaporator temperature sensorOpon or short circuit, faulty sensor22-20
t
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Troubleshooting
Evaporator Temperature Sensor
Recirculation indicator light indicates Diagnostic Trouble code (OTC) 3: A problem in the evaporator temperature sensor circuit.
The evaporator temperature sensor is a temperature dependent resistor {thermistor}. The resistance of the thermistordecreases as the evaporator outlet air temperature increases.
EVAPORATOR TEMPEMTURE SENSOR
Terminal side of mal€ terminals
RESISTANCEko
86'F30"c
HEATER CONTROL PANEL 2OP CONNECTOR
Wire side of fema16 terminals
Self-diagnosis circuit check indicates a problem in the avapora-tor tempeleture ssnsor circuit,
Ch€ck the ev.porato. tempera-ture sensor:1. Disconnect the evaporatortemperature sensor 2P con-
2. Measure the resistancebetween the No. 1 and No. 2torminals of the evaporatortemperature sensor.
ls the resistance within the speci,fications shown on the 9raph.
Check lor a short in the wire:l Remove the heater controlpanel (see page 22-46).2. Check tor continuity betweenthe No.2 terminal ol theheater control panel 20P con,nector and body ground.
Repai. short in the wir6 betwa€nlhe hoater control Danol and theevaporatoa tampereturc senSoa.
fo page 22.21
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From page 22-20
Chock tor an oDen in th€ wire:Check for continuity betlveen theNo. 2 terminal of the heater con-trol oanel 20P connector and theNo.2 terminal oI the evaporatortemperature sensor 2P connoctor.
Fopair open in the wiro betweentho heato. control penel and theevaporator tempetatule sensor.
Check for rn opsn in tha wiJe:Check for continuity between theNo. 9 terminal of the heater control oanel 20P connector and theNo. 'l terminal ot the evaporatortemperature sensor 2P connector,
Ropair open in tho wire betwegnthe heater control oanel and theevaporator tgmpcrature sen3or.
Chgck fol loose wiros or pool
connectrons at the hoator controloan6l 20P connector and at theeveporator temperatura Sensol2P connector. It the connectionsare good, substitute a known-good he.tel contlol panel, andrech€ck. ll thg symptom/indica-tion 90o3 rwey, roplsce the origi-nal heater control oanel.
HEATER CONTROL PANEL 2OP CONNECTORWire side ol female terminals
EVAPORATOB TEMPERATURE SENSOR2P CONNECTORWire side oI temale terminals
1810
1112131a1516't7181920
GIIN
12,/ l,/689t0
'tl1213lat1516'1718't920
o
+
li-L:t
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Evaporator Temperature
SensorPower Transistor
Test
Dip the sensor in ice water, and measure the resistance
with a digital multimeter. Then pour hot water on the
sensor, and check lor change in resistance.
Compare the resistance reading between the No. | 8nd
No. 2 terminals of the evaporator temperature sensor
with the specifications shown in the following graph;
resistance should be within the specifications.
EVAPOBATOR TEMPERATURE SENSOB
Terminal side ol male terminals
4
RESISTANCEko
t0
50 68 86.F10 20 30'c
22-44
12V 1.2-3.1W
No. 2 ILT GRN/BLK)
No. I IBLU/BLK)
Test
1.Disconnect the 3P connector from the oower tran-
st$or.
Carefully release the lock tab on the No. 2 terminal in
the 3P connector, then remove the terminal and insu-
late it from body ground.
Connect a 1.2 - 3.4 W bulb between the No, 1 and
the No,2 cavity on the 3P connectol
Reconnect the 3P connector to the power transistor.
Turn the ignition switch ON (ll). and check that the
blower motor runs.
a lf the blower motor runs at half soeed the oower
transistor is OK, replace the heater control panel.
. lf ths blower motor does not run at half soeed,
reDlaca the Dower transistor.
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}-Overhaul
1. Remove the filter lid. then pull out the A/C filter
assembly.
Pull out the evaporator temperature sensor from
the evaporator fins.
Remove the self-tapping screws and the clamps
from the housings.
Carefully separate the housings, then remove the
evaporator.
lf necessary, remove the expansion valve When
loosening the nuts of the expansion valve, use a sec-
ond wrench to hold the expansion valve or the evapo-
rator line. Otherwise, they can be damaged.
6. Reassemble the evaporator in the reverse order of
disassembly. Make note of these items.
. 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 right O-rings
for HFC-'134a (R-134a) to avoid leakage.
. Install the expansion valve capillary tube with
the capillary tube in contact with the outlet line
directly, and wrap it with electricaltape.
. Reinstall the evaporator temperature sensor to
its original location.
. Make sure that there is no air leakage.
ELECTRICAL TAPEReplace.Make sure there is no foreign matter stuck between
the capillary tube and outlet line.
CAPILLARY TUAE
EXPANSION VALVE
4.
TEMPERATURESENSORlest, page 22-41
,m
\!{
YFILTER LID
;
I-OWER HOUSINGA/C FILTER ASSEMBLY
22-49
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A/C System Service
Pressure Test Chart
NOTE: Performance Test is on page 22-56.
Test resultsRelatad symptomsPrcbable caus€Remody
Discharge (high)pressure 6bnormallyhagh
After stopping compressor, pressuredrops to about 200 kPa 12.0 kgtlcm,,28 psi) quickly, and then lalls gradualty.
Air in systemDischarge, evacuate, and rechargewith specified amount.Evacuation: see page 22-60Charging: see page 22-61No bubbles in sight glass whencondenser is cooled by waterExcessive refrigerant in systemDischarge, evacuate, and rechargewith specilied amount.Reduced or no air flow throughcondenser. Clogged condenser or radia-tor fins. Condenser or radiator fannot wo.king properly
CleanCheck voltage and fan rpm.Check fan direction.
Line to condensor is excossivelv hot.Restricted flow of relrigerant insy$emFestricted lines
Discharge pressureabnormally lowExcessive bubbles in sight glass;condenser is not hot.Insufficient retrigerant inCheck for leak.Charge system.High and low pressures are balancedsoon after stopping compressor. Lowside is higher than normal.
. Faulty compressor discharge
. Faulty compressor seal
Replace the comprossor.
Outlet ot expansion valve is notfrosted, low-pressure gauge indicates
' Faulty expansion valve. Moisture in system. Replace. Discharge, evacuate, andrecharge with specified amount.Suction {low) pros,sure abnormallyExcessive bubbles in sight glass;condenser is not hot.Insufficiont relrigerant inRepair the leaks.Discharge, evacuate, andrecharge with specified amount.Charge as r€quired.Expansion valve is not frosted, andlow-pressure line is not cold. Low-pressure gauge indicates vacuum.
' Frozen expansion valvelMoisture in system). Faulty expansion valve
. Discharge, evacuate, andrecharge with specitied amount.. Replace th€ expansion valve.Discharge temperature is low, and theair llow trom vents is restricted.Frozen evaporatorRun the fan with compressor off,then check evaporator tempera,ture sensor.Expansion valve is frosted.Clogged expansion valveClean or replace.Feceiver/dryer outlet is cool, and inlotrs w6rm (should be warm duringoperation).
Clogged receiver/dryerReplace
Suction pressureabnormally highLow-pressure hose and check joint arecooler than tho temperature aroundevaporator.
. Expansion valve open too long. Loose expansion capillarytube
Repair or roplace.
Suction pressure is lowored whencondenser is cooled by water.Excessive refrigerant in systemDischarge, evacuate, and rechargewath specified amount.High and low-pressure are equalizedas soon as tho compressor is stopped,and both gauges tluctuate whilerunning.
Faulty gasketFaulty high-pressure valveForeign panicle stuck in high-
Replace the compressor.
Slction and dis,charge pressutesabnormally high
Reduced air flow through condens€r,. Clogged condenser orradiator tins. Condenser or radiator fannot working properly
CleanCheck voltage and fan rpm.Check Ian direction.
No bubbles in sight glass whencondenser is cooled by walerExcessive refrigerant jn systemDischarge, evacuate, and rechargewith specified amount.Suction and dis-charge pressureabnormally low
Low-pressure hose and motalendareas are cooterlhan evaporator.Clogged or kinked low-pressure hose pansRepair or replace.
Temperature around expansion valvers too low compared with that aroundClogged high-pressure lineRepair or replace.
Refrigerant leaksCompressor clutch is diny.Compressor shaft seal leakingReplace the compressor.Compressor boltls) are dirty.Leaking around bolt(s)Tighton bolt{s) or replacecompressor.Compressor gasket is wet with oil.Gasket leakingReplace the compressor,
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