sensor MITSUBISHI MONTERO 2000 Service Repair Manual

HEATER, AIR CONDITIONER AND VENTILATION - Troubleshooting55A-7
TROUBLESHOOTING
Trouble symp-
tomProbable causesRemedyRefer-
ence
page
The rear cool-Malfunction of fuseReplace the fuse.–
er does notMalfunction of harness or connectorRepair the harness or connector.–operate.
Refrigerant leak or overfilling of refrigerantReplenish the refrigerant, repair the leak
or take out some of the refrigerant.–
Malfunction of the rear A/C switchReplace the rear A/C switch.55A-32
Malfunction of the front rear fan switchReplace the front rear fan switch.55A-33
Malfunction of the air thermo sensorReplace the air thermo sensor.55A-39
Malfunction of the rear blower relayReplace the rear blower relay.55A-18
The rear blower motor is defective.Replace the rear blower motor.55A-40
The rear cooler control unit is defective.Replace the rear cooler control unit.55A-34
When the rear
cooler is oper-
ating, temper-
ature inside
the passenger
compartment
does not de-
crease(cool air
is not emitted).Refrigerant leakReplenish the refrigerant and repair the
leak.–
When the rear
heater is oper-
ating, temper-
ature inside
the passenger
compartment
does not in-
crease(warm
air is not
emitted).Malfunction of the air thermo sensorReplace the air thermo sensor.55A-39
The blowerMalfunction of fuseReplace the fuse.–
motor does notMalfunction of harness or connectorRepair the harness or connector.–run.
Malfunction of the rear blower relayReplace the blower relay.55A-18
The rear blower motor is defective.Replace the blower motor.55A-40
Malfunction of the rear A/C switchReplace the rear A/C switch.55A-32
Malfunction of the front rear fan switchReplace the front rear fan switch.55A-33
Malfunction of the resistorReplace the resistor.55A-35
The rear cooler control unit is defective.Replace the rear cooler control unit.55A-34
The blowerMalfunction of fuseReplace the fuse.–
motor does notMalfunction of harness or connectorRepair the harness or connector.–stop running.
Malfunction of the rear A/C switchReplace the rear A/C switch.55A-32
Malfunction of the front rear fan switchReplace the front rear fan switch.55A-33
Malfunction of the resistorReplace the resistor.55A-35
The rear cooler control unit is defective.Replace the rear cooler control unit.55A-34


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55B-1
HEATER, AIR
CONDITIONER AND
VENTILATION

CONTENTS
SERVICE SPECIFICATIONS 2.................
LUBRICANTS 2..............................
SPECIAL TOOLS 3...........................
TROUBLESHOOTING 3........
TROUBLESHOOTING 3.........
ON-VEHICLE SERVICE 24...................
Magnetic Clutch Test 24.........................
Idle Up Operation Check 25.............
FRONT A/C 25..............................
Automatic A/C Control Panel Assembly
(A/C-ECU) 25..................................Blower Linear Controller 26......................
Air Mix Damper Motor and
Air Outlet Changeover Damper Motor 27..........
Heater Water Temperature Sensor 29.............
PHOTO SENSOR 30........................
OUTSIDE AIR TEMPERATURE SENSOR 30..
REAR A/C 30...............................
Electric Motor for Air Outlet Changeover
Damper 30....................................
REFRIGERANT LINE 31.....................
COMPRESSOR 33...........................


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HEATER, AIR CONDITIONER AND VENTILATION -Troubleshooting 55B-4
INSPECTION CHART FOR DIAGNOSIS CODES
Code No.Diagnosis itemReference
page
11Inside air temperature sensor system (open circuit)55B-4
12Inside air temperature sensor system (short circuit)55B-4
13Outside air temperature sensor system (open circuit)55B-4
14Outside air temperature sensor system (short circuit)55B-4
15Heater water temperature sensor system (open circuit)55B-5
16Heater water temperature sensor system (short circuit)55B-5
21Air thermo sensor system (open circuit)55B-5
22Air thermo sensor system (short circuit)55B-5
31Potentiometer system for the air mix damper55B-6
32Potentiometer system for the air outlet changeover damper55B-7
INSPECTION PROCEDURE FOR DIAGNOSIS CODES
Code No.11, 12 Inside air temperature sensor systemProbable cause
Code No.11 is set when the inside air temperature circuit inside the A/C-ECU is
open. Meanwhile, code No.12 is set when it is short.Malfunction of the A/C-ECU
Replace the automatic A/C control panelassembly (A/C-ECU).
Code No.13, 14 Outside air temperature sensor systemProbable cause
Code No.13 is set when the outside air temperature sensor circuit is open.
Meanwhile, code No.14 is set when it is short.DMalfunction of the outside air temperature sensor
DMalfunction of connector or harness
DMalfunction of the A/C-ECU
OK
Replace the automatic A/C control panelassembly (A/C-ECU).
NG
Check the harness wire between the outside air temperature
sensor and the A/C-ECU.NG
Repair
OK
Check the trouble symptoms.
OK
Check the following connectors:A-30, D-27, D-132NG
Repair
Check the outside air temperature sensor (Refer to P.55B-30).NG
Replace


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HEATER, AIR CONDITIONER AND VENTILATION -Troubleshooting 55B-5
Code No.15, 16 Heater water temperature sensor
systemProbable cause
Code No.15 is output when the heater water temperature sensor circuit is open.
Code No.16 is output when that circuit is short.DMalfunction of the heater water temperature sensor
DMalfunction of connector or harness
DMalfunction of the A/C-ECU
OK
Replace the automatic A/C control panelassembly (A/C-ECU).
NG
Check the harness wire between the heater water temperature
sensor and the A/C-ECU.NG
Repair
OK
Check the trouble symptoms.
OK
Check the following connectors:D-19, D-132NG
Repair
Check the heater water temperature sensor
(Refer to P.55B-29).NG
Replace
Code No.21, 22 Air thermo sensor systemProbable cause
Code No.21 is set when the air thermo sensor circuit is open. Meanwhile, code
No.22 is set when it is short.DMalfunction of the air thermo sensor
DMalfunction of connector or harness
DMalfunction of the A/C-ECU
OK
Replace the automatic A/C control panelassembly (A/C-ECU).
NG
Check the harness wire between the air thermo sensor and
the A/C-ECU.NG
Repair
OK
Check the trouble symptoms.
OK
Check the following connectors:D-129, D-132NG
Repair
Check the air thermo sensor
(Refer to GROUP 55A - Front A/C).NG
Replace


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HEATER, AIR CONDITIONER AND VENTILATION -Troubleshooting 55B-10
Inspection procedure 4
A/C outlet air temperature can not be set.
Probable cause
If the air outlet temperature can not be changed after a A/C temperature is set,
sensor(s) or the air mix damper may be defective.DMalfunction of the inside air temperature sensor
DMalfunction of the outside air temperature sensor
DMalfunction of the heater water temperature sensor
DMalfunction of the photo sensor
DMalfunction of the electric motor for the air mix
damper
DMalfunction of harness or connector
DMalfunction of the A/C-ECU
NG
Repair
NG
Repair
OK
Replace the automatic A/C control panelassembly (A/C-ECU).
OK
MUT-
IIData list
31 Potentiometer for air mix damperNGCheck the air mix damper potentiometer system
(Refer to P.55B-6, Code No.31).
NG
Check the harness wire between the photo sensor and the
A/C-ECU.
OK
Check the trouble
symptoms.
OK
Check the following connectors:D-132, D-106
OK
MUT-
IIData list
25 Photo sensorNGCheck the photo sensor (Automatic air conditioner).
(Refer to P.55B-30.)
OK
MUT-
IIData list
15 Heater water temperature sensorNGCheck the heater water temperature sensor system.
(Refer to P.55B-5, Code Nos.15, 16.)
OK
MUT-
IIData list
13 Outside air temperature sensorNGCheck the outside air temperature sensor system.
(Refer to P.55B-4, Code Nos.13, 14.)
NO
MUT-
IIData list
11 Inside air temperature sensorNGReplace the automatic A/C control panelassembly (A/C-ECU).
MUT-
IISelf-Diag Code
Are diagnosis codes displayed?YESInspection chart for diagnosis codes (Refer to P.55B-4.)
NG
Repair OKReplace the automatic A/C control panel
assembly (A/C-ECU).
NG
Check the harness wire between the air mix damper motor
and the A/C-ECU.NG
Repair
OK
Check the trouble symptoms.
OK
Check the following connectors:D-130, D-131NG
Repair
Check the air mix damper motor (Refer to P.55B-27).NG
Replace OK


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HEATER, AIR CONDITIONER AND VENTILATION -Troubleshooting 55B-16
Inspection procedure 11
The condenser fan does not operate <4D56>.
Probable cause
If the condenser fan does not operate, the condenser fan relay or motor may be
defective.DMalfunction of the condenser fan relay
DMalfunction of harness or connector
DMalfunction of the engine-A/T-ECU or
engine-ECU
NG
Check the harness wire between the condenser fan relay and
the ignition switch (IG2), and repair if necessary.
NG
Repair
NG
Check the harness wire between the condenser fan motor and
body earth, and repair if necessary.
NG
Repair
NG
Repair
OK
NG
Check the harness wire between the condenser fan relay and
fusible link (1), and repair if necessary.
NG
Repair
NG
Check the harness wires between the condenser fan relay
and the condenser fan motor and between the condenser fan
relay and theengine coolant temperaturesensor, and repair if
necessary.
OK
Check the trouble symptoms.
OK
Check the following connectors:A-10X, A-27, A-04 drive vehicles>, D-143, B-47
OK
Check the trouble symptoms.
OK
Measure at condenser fan motor connector A-27.
DDisconnect the connector and measure at the harness
side.
DContinuity between terminal 2 and body earth
OK:ContinuityNGCheck the following connector:A-27
OK
Check the trouble symptoms.
Check the following connector:A-10X
(2) NG
OK
Check the trouble symptoms.
OK
Measure at condenser fan relay connector A-10X.
DDisconnect the connector, and measure at the J/B side.
DIgnition switch: ON
(1) Voltage between terminal 3 and body earth
OK:System voltage
(2) Voltage between terminal 5 and body earth
OK:System voltage(1) NGCheck the following connectors:A-10X, A-15, D-27, D-210,
D-208
OK
Check the condenser fan motor
(Refer to GROUP 55A - Condenser Fan).NG
Replace
Check the condenser fan relay
(Refer to GROUP 55A - On-vehicle Service).NG
Replace
NG
ReplaceReplace the engine coolant temperaturesensor.


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HEATER, AIR CONDITIONER AND VENTILATION -Troubleshooting 55B-17
DATA LIST REFERENCE TABLE
Item No.Check itemInspection contents
11Inside air temperature sensorIgnition switch: ONInside air temperature and tempera-
ture displayed on the MUT-IIare
identical.
13Outside air temperature sen-
sorIgnition switch: ONOutside air temperature and tem-
perature displayed on the MUT-II
are identical.
15Heater water temperature
sensorIgnition switch: ONHeater core surface temperature
and temperature displayed on the
MUT-IIare identical.
21Air thermo sensorIgnition switch: ONEvaporator outlet temperature and
temperature displayed on the MUT-
IIare identical.
25Photo sensorIgnition switch: ONAmount of incident light is propor-
tional to voltage displayed on the
MUT-II.
31Potentiometer for the air mix
damperIgnition switch: ON
Damper position: MAX HOTOpening angle: Approximately
100%
Ignition switch: ON
Damper position: MAX COOLOpening angle: Approximately 0%
32Potentiometer for the air
outlet changeover damperIgnition switch: ON
Damper position: FACEOpening angle: Approximately 0%
Ignition switch: ON
Damper position:FOOTOpening angle: Approximately 60%
Ignition switch: ON
Damper position: FOOT/DEFOpening angle: Approximately 80%
Ignition switch: ON
Damper position: DEFOpening angle: Approximately
100%
ACTUATOR TEST TABLE
Item No.Check itemDrive Contents
01Blower motorStopped
02Low speed
03Medium speed
04High speed
05Electric motor for the air mix damperOpening angle: Approximately 0%
06Opening angle: Approximately 50%
07Opening angle: Approximately 100%
08Electric motor for the air outlet changeoverFACE
09damperFOOT
10DEF
11Compressor ON/OFFOFF
12ON
13Inside/outside air changeover damper motorOutside air
14Inside air


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HEATER, AIR CONDITIONER AND VENTILATION -Troubleshooting 55B-19
Termi-
nal No.Normal condition Check conditions Check item
15Rear defoggerRear defogger: OFFSystem voltage
Rear defogger: ON1.5 V or less
16Multi center display unit communication
lineIgnition switch: ONHi: 4 - 5 V
Lo: 0 - 1 V
17Multi center display unit communication
lineIgnition switch: ONHi: 4 - 5 V
Lo: 0 - 1 V
18Multi center display unit communication
line shieldAt all times0V
19Diagnosis outputIgnition switch: ONA voltmeter needle
fluctuates between 0
and 12 V.
20Input from A/C compressor relayWhen the A/C is off.0V
When the A/C is in operation
(When compressor is operating)System voltage
21Power supply to potentiometerAt all times5V
22Input from outside air temperature
sensorSensor temperature: 25
_C (1.7 kW)1.9 V
23Input from heater water temperature
sensorSensor temperature: 25
_C(5kW)2.8 V
24Input from potentiometer for air mix
damperWhen the damper flap is moving to the
MAX HOT position.0.7 - 1.3 V
25Power supply to illuminationLighting switch: ONSystem voltage
26Power supply to ignition switch (IG2)Ignition switch: ONSystem voltage
27Power supply to ignition switch (ACC)Ignition switch: ACCSystem voltage
28Backup power supplyAt all timesSystem voltage
29Earth to sensor and potentiometerAt all times0V
30Input from air thermo sensorSensor temperature: 25
_C (1.5 kW)2.2 V
31Photo sensor (+)During 800 kcal/m2-h1V
32Input from potentiometer for the air
outlet changeover damperWhen the damper flap is moving to the
DEF position.0.7 - 1.3 V
33Diagnosis inputIgnition switch: ON0V
34Compressor lock signal (ignition signal)Engine speed: 3 000 r/min0.3 - 3.0
35Illumination earthAt all timesContinuity
36EarthAt all timesContinuity
CHECK AT ENGINE-A/T-ECU OR ENGINE-ECU TERMINALS
Refer to GROUP 13A – Troubleshooting or GROUP 13B – Troubleshooting .


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HEATER, AIR CONDITIONER AND VENTILATION -Troubleshooting 55B-21
Inspection procedure 2
The rear A/C outlet air temperature can not be set.
Probable cause
If the air outlet temperature can not be changed after a temperature control
switch is operated,the temperature control switch, the air thermo sensor, the
magnet valve or the air mix damper maybe defective.DMalfunction of the rear A/C switch
DMalfunction of the air thermo sensor
DMagnet valve
DMalfunction of the electric motor for the air mix
damper
DMalfunction of harness or connector
DMalfunction of the rear A/C control unit
Repair
NG
NG
Check the harness wire between the rear A/C control unit and
the rear A/C switch, and repair if necessary.
NG
RepairNG
Check the harness wire between the rear A/C control unit and
the air thermo sensor, and repair if necessary.
NG
Repair
NG
Check the harness wire between the rear A/C control unit and
the air mix damper motor, and repair if necessary.
OK
Replace the rear A/C control unit.NG
Repair
NG
Check the harness wire between the rear A/C control unit and
the magnet valve, and repair if necessary.
OK
Check the trouble symptoms.
Check the following connectors:E-23, D-123, G-26,
G-24-1, G-24-4
(6) NG
OK
Check the trouble symptoms.
Check the following connectors:E-23, D-123, G-24,
G-24-1, G-24-2(3 - 5) NG
OK
Check the trouble symptoms.
Check the following connectors:E-23, D-123, G-26,
G-24-1, G-24-3(2) NG
OK
Check the trouble symptoms.
OK
Measure at rear A/C control unit connector E-23.
DConnect the connector.
DIgnition switch: ON
(1) Voltage between terminal 3 and body earth
OK:1 V (Temperature control switch: MAX HOT),
4 V (Temperature control switch: MAX COOL)
(2) Voltage between terminal 12 and body earth
OK:2.2 V [Air thermo sensor temperature: 25
_C
(1.5 k
W)]
(3) Voltage between terminal 7 and body earth
OK:1 V (Air mix damper: MAX HOT),
4 V (Air mix damper: MAX COOL)
(4) Voltage between terminal 6 and body earth
OK:10 V (When the air mix damper flap is moving to the
MAX COOL position), 0.5 V (When the air mix
damper flap is moving to the MAX HOT position)
(5) Voltage between terminal 14 and body earth
OK:0.5 V (When the air mix damper flap is moving to
the MAX COOL position), 10 V (When the air mix
damper flap is moving to the MAX HOT position)
(6) Voltage between terminal 1 and body earth
OK:System voltage (magnetic valve: OFF), 0.5 V (mag-
netic valve: ON)(1) NGCheck the following connectors:E-23, D-123, E-119
OK
Check the magnetic valve.
(Refer to GROUP 55A - Rear Heater/Rear Cooler.)NG
Replace
OK
Check the air mix damper motor.
(Refer to GROUP 55A - Rear Heater/Rear Cooler.)NG
Replace
OK
Check the air thermo sensor.
(Refer to GROUP 55A - Rear Heater/Rear Cooler.)NG
Replace
Check the rear A/C switch (temperature control switch).
(Refer to GROUP 55A - Rear Heater/Rear Cooler.)NG
Replace


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