sensor MITSUBISHI 3000GT 1991 Service Manual

FULL AUTO AIR CONDITIONER - Troubleshooting55-495. Inspection of belt lock controller circuit
Compressor relay
tAir conditioner control unitAir conditioner
+control panelAir
condltloner,c.compressor commandAH condmonerarithmetic
circuitcompressor ONstgnal
ComparatorAir condltlonercompressor ON signal20 FOO58
Revolution pickup sensor
LiTroubleshooting Hintsl Air conditioner control unit terminal voltages
Terminal No.
Signal nameConditionTerminal voltage
11Air conditioner outputCompressor ONIO V to battery voltage
TSB Revision

SERVICE DATA
ternno.Inspection
point
MethodCriteria
Probable cause
Normal
AbnormalRemedy11 Room-temper- Measure resistance of
sensor when room tem- ature sensorperature is 25°C (77°F).
Approx. 4 kS1Largely devrates
from approx.Defective room-tempera-
Replace room-tempera-
ture sensor
ture sensor.4
kll
Measure voltage across
In approx.
terminal @I of airOpen-circuited harness
Correct harness.2.3-2.9v-conditioner control unitbetween room-temperaturerange
sensor and air condrtionerand ground when room
control unittemperature is 25°C (77°F).Outside approx.
Poor connection of air
Correct connector-2.3-2.9vconditioner control unit
connection or replace’rangeconnector or defective air
air conditioner control
conditioner control unitunit.13
Outside-air-
Measure resistance of
Approx. 4 kllLargely deviates
Defective outside-air
Replace outside-air-temperaturesensor when ambient tem-
from approx. 4 kf2sensor
temperature sensor.
sensorperature is 25°C (77°F).
Measure voltage acrossIn approx.terminal @of air controlOpen-crrcuited harnessCorrect harness.2.2-2.8V-between outside-air-
conditioner unrt and
range
temperature sensor and
ground when ambient
air conditioner control unit
temperature is 25°C (77°F).Outside approx.Poor connection of air-
Correct connector-2.2-2.8Vconditioner control unit
connection or replacerangeconnector or defectiveair conditioner control
air conditioner control unitunit.15 Water-temper- Measure resistance of
ConductiveNonconductiveDefective water-
Replace water-
ature sensor
sensor when watertemperature sensor
temperature sensor.
temperature is 22.5 to
30.5”C (57.6 to 86.9”F).21 Air therm0
sensorMeasure voltage acrossApprox. 12 V
Open-circuited harness
Correct harness.terminal @ of air condi--between water-temperaturetioner control unit and
sensor and air conditioner
ground when water tempera-
control unit
ture is 22.5 to 30.5”C(57.6 to 86.9”F).Largely deviatesPoor connection of airCorrect connector-from approx. 12 Vconditioner control unitconnection or replace
connector or defectiveair conditioner control
air conditioner control unitunit.
Measure resistance of
sen-Approx. 4 kS2Largely deviatesDefective air therm0Replace air therm0
sor when sensor’s sensing
from approx. 4 kb2sensorsensor.temperature is 25°C (77°F).
Measure voltage acrossIn approx.Open-circuited harness be-Correct harness.termrnal 0 of air conditioner2.3 - 2.9 V-tween air therm0 sensor and
control unit and groundrangeair conditioner control unit
when sensor’s sensing
temperature is 25°C (77°F).Outside approx.
Poor connection of airCorrect connector2.3-2.9vconditioner control unitconnection or replace
rangeconnector or defectiveair conditioner control
air conditioner control unit
unit.31 Air
mrx
Refer to P. 55-59.Defective air mix damperReplace air mix damper
damperpotentiometerpotentiometer.
potentiometer
-Measure voltage acrossIn approx.
Open-circuited harnessCorrect harness.
terminal @of airO.l-0.3v-between air mrx damper
conditioner control unitrangepotentiometer and arrand ground when potentio-conditioner control unrtmeter is in MAX. COOL
position.Outside approx.Poor connection of airCorrect connector
-0.1 -0.3vconditioner control unitconnection or replace
rangeconnector or defectiveair conditioner control
air conditioner control unitunit.33 Outlet
Refer to P. 55-59.Defective outlet selectorReplace outlet selector
selectordamper potentiometerdamper potentiometer.
damperpotentiometer
Measure voltage acrossIn approx.Open-circuited harnessCorrect harness.terminal @of air0.1 -0.3v-between outlet selectorconditioner control unitrangedamper potentiometerand ground when potentio-and air conditioner control
meter is in FACE position._Outside approx.Poor connection of airCorrect connector-0.1 -0.3vconditioner control unitconnection or replace
rangeconnector or defectiveair conditioner control
air conditioner control unit
unit.FULL AUTO AIR CONDITIONER
- Troubleskootina
1 TSB Revision

FULL AUTO AIR CONDITIONER - Troubleshootina55-55
DIAGNOSISDISPLAY PAlTERNS AND CODES
/
L
ii
CodeDisplay pattern (output codes)CauseFail safe(use with voltmeter)
0Normal
ON
OFFContinuous
I1 n
Open-circuited room-temperature sensorCondition in which 25°C
(77°F) is detected
I2 n
Short-circuited room-temperature sensor
I3 n
Open-circuited outside-air sensorCondition in which 20°C
(68°F) is detected
I4 n
Short-circuited outside-air sensor
12A0104
21 -,llJlL
Open-circuited air therm0 sensorCondition in which -2°C(-35.6”F) is detected
22 nn
Short-circuited air therm0 sensor
31 J-[-u1 1Short-circuited and open-circuitedair mix damper potentiometerMAX. HOT(or MAX. COOL when itis at MAX. COOL)
32 nnn
Short-circuited and open-circuitedDEF.mode selector damper potentiometer(or FACE when it isat FACE)
12A0107
41, nnnn
Defective air mix damper motor
42Defective mode selector damper motor
1uuuI nn12A0105
NOTE:(1) If two or more abnormal conditions occur at the same time, the code numbers are alternately displayed, in
order, repeatedly.
(2) The nature of the malfunction is entered and stored in the memory from the time the malfunction occurs until
the ignition switch is next turned to OFF.TSB Revision

55-60
SENSORSFULL AUTO AIR CONDITIONER
- Sensors
REMOVAL AND INSTALLATIONM550A- _
4*1. Passenger compartment temperature sen-sor2OFOO63
Outside air sensor removal steps
2. Stopper
3. Glove box outer case
4. Photo sensor connector connection
5. Photo sensorWater temperature sensor removal steps
2. StopperI3: F/it; box outer case assembly
7. Water temperature sensorOutside-air-temperature sensor removal steps
2. Stopper
3. Glove box outer case assembly
8. Outside-air-temperature sensor
82OFOO75
-
Passenger compartment
temperature sensor
SERVICE POINTS OF REMOVALM5506AE
1. REMOVAL OF PASSENGER COMPARTMENT TEMPER-
ATURE SENSOR
2OPO164LlTSB Revision
Using the trim stick, remove the passenger compartmenttemperature sensor from the headlining.
I~’
I
d
I
d

FULL AUTO AIR CONDITIONER - Sensors55-615. REMOVAL OF PHOTO SENSOR
Using a trim stick, remove the photo sensor from the
defroster garnishes.
Thermometer
2OAO19:
c
3
INSPECTIONM55OcALl
WATER TEMPERATURE SENSOR
(1) Dip the water-temperature sensor in hot water and, using astove, etc., raise the water temperature.
(2) Check that the water-temperature sensor is conductive
when the water temperature reaches the specified temper-
ature.Standard value: 26.5 + 4°C (79.7
+ 7.2”Fl
OUTSIDE-AIR-TEMPERATURE SENSOR
The condition can be considered normal if the resistances are
measured within the ranges of 3.98
- 4.12 kilohms and 2.21 -
2.35 kilohms, respectively, when the outside-air-temperature
sensor is submerged in warm water of 25°C (77°F) and 40°C(104°F) for one minute or longer each.
NOTE
The relationship between the outside-air-temperature and theresistance values is as shown below.
&$$nt temperatureI-10 /0110 / i01 25/ 301 40 /(14) (32) (50) (68) (77) (86) (104)
Resistance value(reference) k0
1 TSB Revision