sensor MITSUBISHI 3000GT 1991 Service Manual

55-26HEATERS AND MANUAL AIR CONDITIONER - Evaporator
DISASSEMBLY AND REASSEMBLYM55RE- -Compressor oil: Freol S-83 or
Suniso 5GS
Disassembly steps
4*1. Clips
2. Evaporater case (upper)3.
Fin therm0 sensor4. AirInlet sensor
4*

5. Evaporator case (lower)
6.Evaporator assembly
7.Grommet8.Insulator9.Rubber insulator10.Clip11. Expansion valve
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SERVICE POINTS OF DISASSEMBLYM55RFAJ1. REMOVAL OF CLIPS
Remove the clips with a screwdriver covered with a shoptowel to prevent damage to case surfaces.
11. REMOVAL OF EXPANSION VALVE
Loosen the flare nut by using two wrenches (for both theinlet and outlet).

HEATERS AND MANUAL AIR CONDITIONER - Compressor
DISASSEMBLY AND REASSEMBLY
55-29
M55SE- -16
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Magnetic clutch disassembly steps
1. Bolts
2. Pulley
l * l *3. Nutl *4. Armature plate
gI i;yirring
l *7. Snap ringF* 8. Clutch coil9. ShimsControl valve disassembly
13. Snap ring14. Control valveThermostat and revolution pick up sensor disassem-
bly steps
15. Plate16. Thermostat and revolution pick up sensorHigh pressure relief valve disassembly steps
10. Cover11. Dust cover
12. High pressure relief valveTSB Revision

HEATERS AND MANUAL AIR CONDITIONER - Compressor55-3120N003d
2OFOO96
I
Ec-3
3180?+I! (25)zz
h34\
*
Engine speed rpm2OPO2S
\CrankshaftTapered part
20A0157
REVOLUTION PICK UP SENSOR CHECKMeasure the resistance between terminals
@ and @ of the
connector.
Normal resistance: 405 + 35 R when ambient temperatureis
20°C (68°F)
If the measurement deviates greatly from the above resis-
tance, replace the revolution pick up sensor assembly.
CONTROL VALVE CHECKThe control valve detects a low pressure level during the
operation of the air conditioner, and adjusts the amount of
refrigerant to be bypassed.
(1) Operate the air conditioner under a high temperature loadcondition (when vehicle interior temperature is high).
(2) Connect a low pressure gauge to the air compressor.
(3) Operate the air conditioner with the engine running at idle.
(4) Gradually increase the engine speed while observing the
low pressure gauge.
If the valve is normal, the low pressure drops slowly as the
engine speed increases until a pressure of 180
kPa (25 psi)
is reached, at which point the pressure temporarily ceasesto drop. Then, the pressure again starts dropping as the
engine speed further increases.If the valve is abnormal, the low pressure drops in direct
proportion to the increase in engine speed without a
temporary leveling off at the 180 kPa (25 psi) pressure level.
If the low pressure drops like this, replace the control valve.
SERVICE POINTS OF REASSEMBLYM556HAF
8. INSTALLATION OF CLUTCH COIL
Align the pin of the clutch coil with the pin hole in the fronthousing, and then fit it into the hole.
7. INSTALLATION OF SNAP RING
Install the snap ring so that the tapered surface is at the
outer side.
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55-36 HEATERS AND MANUAL AIR CONDITIONER -Ventilators (Instrument Panel)
VENTILATORS (INSTRUMENT PANEL)M55YA- -
REMOVAL AND INSTALLATION
-16
/‘4
Removal steps
l * +a1. Knee protector
(Refer to GROUP 52A-Instrument Panel.)
2. Foot shower duct
3. Lap cooler duct
4. Under cover
5. Belt lock controller
6. Side defroster hoses A
7. Duct (Vehicles without air conditioner)
** l +8. instrument panel (Refer to GROUP 52A-instrument Panel.)
9. Center duct
10. Air duct (right side)
11. Air duct (left side)12. Distribution duct (center)
13.Defroster duct14. Side defroster hoses B
15. Defroster garnishes
16.Photo sensor17. Center air outlet assembly
18. Side air outlet assembly
19. Distribution duct (foot)2OFOO55
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HEATERS AND MANUAL AIR CONDITIONER -Ventilators (Instrument Panel) 55-37
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SERVICE POINTS OF REMOVALM55YBAH
15. REMOVAL OF DEFROSTER GARNISHES
Using the trim stick, remove the defroster garnishes fromthe instrument panel.
16. REMOVAL OF PHOTO SENSORUsing the trim stick, remove the photo sensor from the
defroster garnish.
17. REMOVAL OF CENTER AIR OUTLET ASSEMBLY
Disengaging the clips (2 positions) of the center air-outlet
assembly with a flat tip screwdriver, remove the center airoutlet assembly with the trim stick.
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FULL AUTO AIR CONDITIONER - Troubleshootina55-41
Symptom
4ir conditioner doeslot operate when the
gnition switch in the
3N position.
nterior temperature
lees not raiseNo warm air coming1ut).
nterior temperatureAoes not lowerNo cold air coming,ut).Probable cause
Open-circuited power circuit harness
Defective control panel
Defective air conditioner control unit
Defective room-temperature sensor
input circuit
Defective air mix damper
potentiometer input circuit
Remedy
Correct harness.
Replace control panel.
Check diagnosis output.
Check diagnosis output.Replace defective parts.
Defective air mix damper drive motorReplace air mix damper drivemotor.
Incorrect engagement of air mix
damper drive motor lever and air mix
damperEngage correctly.
Sticking air mix damper
Open-circuited harness between air
mix damper drive motor and airconditioner control unit
Defective control panel
Defective air conditioner control unit
Correct air mix damper.
Correct harness.
Replace control panel.
Replace air conditioner
control unit.
Defective room-temperature sensor
input circuit
Defective outside-air-temperature
sensor input circuit
Check diagnosis output.
Replace defective parts.
Defective air therm0 sensor input
circuit
Defective refrigerant-temperature
sensor input circuit
Defective air mix damper
potentiometer input circuit
Defective photo sensor
Replace photo sensor.
Defective air mix damper drive motorReplace air mix damper drive
motor.
Incorrect engagement of air mixdamper drive motor lever and airmix damper
Engage correctly.
Sticking air mix damper
Open-circuited harness between air
mix damper drive motor and airconditioner control unit
Open-circuited harness between
photo sensor and air conditioner
control unit
Correct air mix damper.
Correct harness.
Correct harness.
Defective air-conditioner compressorReplace.
relay in the relay boxTSB Revision
Ref. page
55-56
55-56
55-55
55-58
55-56
55-56
55-55
55-60
55-58

55-44FULL AUTO AIR CONDITIONER - Troubleshooting
READING THE “CIRCUIT AND UNIT CHECK”
3. hvqection Of compartment-temperature sensor, outside-air-temperature sensor, and air thermosensor circuits
Air condMnercompressor relay
Compartmenttemperat”re93”SCNFinX”SCH0utsrde.wtemperatureX”SOl
oubleshooting Hints
DlagnosrsNo. 11, 12 [Fix compartment temperature sensor input signal at 25°C (77”F).]
No. 13. 14 [Fix outside-air-temperature sensor input signal at 15°C (59”F).]No. 21, 22 [Fix fin therm0 sensor input signal at -2°C (-356”F).]Air conditioner control unit terminal voltagesI-
ermrnal No.Slgnal nameConditronTerrmnal voltage
5Outside-air-temperature sensorTemperature at sensor 25°C (77°F) (4 kf2)2.2-2.8V
10Sensor power sourceNormally4.8 - 5.2 V
16Compartment temperatureTkmperature at sensor 25°C (77°F) (4 k0)2.3-2.9vsensor
17Fin therm0 sensorTemperature at sensor 25°C (77°F) (4 k0)2.3 - 2.9 Vwhen alr conditioner is OFFA14
-
- Connectors are keyed
by terminal numbers.
Indicates the diagnosis
output code
nur6be.r and
system condition when
the code is output.
Indicates the terminal
number to be checked.Indicates the condition
at terminal check.Indicates the specification criteria.
Where no condition is given in the
“Condition” column, the normal
specification value is given.TSB Revision
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55-46FULL AUTO AIR CONDITIONER - Troubleshooting
2. Inspection of potentiometer circuit
Outlet selector
command c~rcutl
i IComparator&8.
c!
t
Ia
Y[ND conversionA/D conversvmWC”l,CllCUll\/ \,1.y
lo” 6”Air conditioner control unit7‘”
94 72-2t4 3
~1
Air mix damper
potentiometer
z=-
4;t
e11I
Outlet
selector
damper
potentiometer
2OFOO57Troubleshooting Hints
l Diagnosis
No. 31 (Fix air mix damper at MAX. HOT position, or at MAX. COOL position when it is at MAX. COOL
position.)
No. 32 (Fix outlet selector damper at FACE position, or at FACE pgsition when it is at FACE position.)l Air conditioner control unit terminal voltages
Sensor power sourceNormally4.8 - 5.2 V
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FULL AUTO AIR CONDITIONER - Troubleshootinn55-47
3. Inspection of compartment-temperature sensor, outside-air-temperature sensor, and air therm0
sensor circuits
Air conditioner
compressor relay
Air conditioner control
unitA~rconditlonercompiessor
command arllhmew ctrcutc#
Sensorpowersource
Controlled variableIControlled variable
-IIIA/D conversion
Compartment
temperaruresensor
Finsensor
?J
Outside air
temperature
sensor2OFOO60
Troubleshooting Hintsl Diagnosis
No. 11, 12 [Fix compartment temperature sensor input signal at 25°C (77°F).
No. 13, 14 [Fix outside-air-temperature sensor input signal at 15°C
(59”Fj.INo. 21, 22 [Fix fin
therm0 sensor input signal at -2°C (-35.6”FJ.ll Air conditioner control unit terminal voltages
Terminal No.Signal nameConditionTerminal voltage
5Outside-air-temperature sensorTemperature at sensor 25°C (77°F) (4 klR)2.2 - 2.8 V
10Sensor power sourceNormally4.8 - 5.2 V
16Compartment temperatureTemperature at sensor 25°C (77°F) (4 klR)2.3 - 2.9 V
sensor
17Fin therm0 sensorTemperature at sensor 25°C (77°F) (4 k0)2.3 - 2.9 Vwhen air conditioner is OFF
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55-48FULL AUTO AIR CONDITIONER - Troubleshooting
[4. Inspection of water-temperature sensor and photo sensor circuits (
Air conditionercontrol panel
A
{ f*)- Potentiometer
‘>/b Damper drive
motor
\/\,9 Air conditioner
a 7 control unit
Water
temperature
sensor
m

Air conditionerEach sensorcontrol unit&
Air control panel
I.L .Solar radmtmnFin speed arlth-compensating ClrC”itmetIC ClrCUlt#t
A/D convertionND convemon
J2010043
I-
Troubleshooting Hintsl Air conditioner control unit terminal voltages
Terminal No.Signal nameConditionTerminal voltage
19Photo sensor 0llluminance 100,000 lux or more-0.1 to -0.2 v
llluminance less than 0 Iuxov
20Photo sensor 0Normallyov
9Water-temperature sensor 0Switch OFF [Engine coolant temperature
less than 50°C (122”F)]
Battery voltage
Switch ON [Engine coolant temperature
0 V
50°C (122°F) or higher]
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