1991 MITSUBISHI MONTERO sensor

AIR RIDE SUSPENSION - COMPRESSORS
AIR RIDE SUSPENSION - COMPRESSOR INSPECTION








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Condition Code Procedure
Attaching hardware bent . B ... Require repair or replacement
of bent part.
Attaching hardware
broken ................. A ... Require replacement of broken
part.
Attaching hardware
loose .................. A ... Require repair or replacement
of loose part.
Attaching hardware
missing ................ C .. Require replacement of missing
part.
Attaching hardware
threads damaged ........ A ... Require repair or replacement
of part with damaged threads.
Attaching hardware
threads stripped
(threads missing) ...... A ..... Require replacement of part
with stripped threads.
Connector bent .......... A .. Require repair or replacement.
Connector broken ........ A ............ Require replacement.
Connector loose ......... A .. Require repair or replacement.
Does not build pressure . A .......... ( 1) Further inspection
required.
Excessive run time ...... B .......... ( 2) Further inspection
required.
Inoperative ............. A ............ Require replacement.
Leaking ................. A .. Require repair or replacement.
Missing ................. C ............ Require replacement.
( 1) - If failure to build pressure is traced to the
compressor, require replacement.
( 2) - If excessive run time is traced to the compressor,
require replacement.









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AIR RIDE SUSPENSION - HEIGHT SENSORS
AIR RIDE SUSPENSION - HEIGHT SENSOR INSPECTION








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Condition Code Procedure
Attaching hardware bent . B ... Require repair or replacement
of bent part.
Attaching hardware
broken ................. A ... Require replacement of broken
part.
Attaching hardware
corroded, affecting
structural integrity .... A .......... Require replacement of
corroded part.
Attaching hardware
loose .................. A ... Require repair or replacement
of loose part.
Attaching hardware
missing ................ C .. Require replacement of missing
part.
Attaching hardware

threads damaged ........ A ... Require repair or replacement
of part with damaged threads.
Attaching hardware
threads stripped
(threads missing) ...... A ..... Require replacement of part
with stripped threads.
Dust boot missing ....... 2 ........ (1) Suggest replacement.
Dust boot split ......... 2 ........ ( 1) Suggest replacement.
Dust boot torn .......... 2 ........ ( 1) Suggest replacement.
Housing cracked ......... A ............ Require replacement.
Lead routing incorrect .. B .. Require rerouting according to
vehicle manufacturer's
specifications.
Loose ................... B ... Require adjustment to vehicle
manufacturer's specifications.
Missing ................. C ............ Require replacement.
Output signal incorrect . A .. Require repair or replacement.
Wire lead damaged ....... A .. Require repair or replacement.
( 1) - This condition can lead to damage of the sliding magnet,
which, in turn, causes premature sensor failure.









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AIR RIDE SUSPENSION - MODULES
AIR RIDE SUSPENSION - MODULE INSPECTION








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Condition Code Procedure
Attaching hardware
loose .................. A ... Require repair or replacement
of loose part.
Attaching hardware
missing ................ C .. Require replacement of missing
part.
Attaching hardware
threads damaged ........ A ... Require repair or replacement
of part with damaged threads.
Attaching hardware
threads stripped
(threads missing) ...... A ..... Require replacement of part
with stripped threads.
Housing cracked ......... 2 .. Suggest repair or replacement.
Inoperative ............. A ............ Require replacement.
Missing ................. C ............ Require replacement.









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AIR RIDE SUSPENSION - RELAYS (COMPRESSOR)
AIR RIDE SUSPENSION - RELAY (COMPRESSOR) INSPECTION








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Condition Code Procedure
Housing cracked ......... 2 ........ ( 1) Suggest replacement.
Intermittent ............ A ............ Require replacement.
Missing ................. C ............ Require replacement.
Output signal incorrect . A ............ Require replacement.
( 1) - If moisture enters the relay, it can reduce life
expectancy or impair function.









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AIR RIDE SUSPENSION - SWITCHES (ON/OFF)

\003
I - S YSTE M /C O M PO NEN T T E STS

1991 M it s u bis h i M onte ro
1991 ENGINE PERFORMANCE
System & Component Testing
Chrysler Motors: Ram-50
Mitsubishi: Montero, Pickup
INTRODUCTION
Before testing separate components or systems, perform
procedures in F - BASIC TESTING article in the ENGINE PERFORMANCE
Section. Since many computer controlled and monitored components set a
trouble code if they malfunction, also perform procedures in G - TESTS
W/CODES article in the ENGINE PERFORMANCE Section.
NOTE: Testing individual components does not isolate shorts or
opens. Perform all voltage tests with a Digital
Volt-Ohmmeter (DVOM) with a minimum 10-megohm input
impedance, unless stated otherwise in test procedure. Use
ohmmeter to isolate wiring harness shorts or opens.
COMPUTERIZED ENGINE CONTROLS
CONTROL UNIT
NOTE: To identify ECU power and ground circuits, see appropriate
L - WIRING DIAGRAMS article in the ENGINE PERFORMANCE
Section.
Ground Circuits
1) ECU is located near right kick panel. Turn ignition off.
Using an ohmmeter, check for continuity between ground and ECU
terminals No. 101 and 106. Resistance should be zero ohms. If
resistance is not zero ohms, repair open circuit between ECU connector
and ground.
2) Connect voltmeter negative lead to ground. Connect
positive lead to ECU ground terminals as in step 1). With vehicle
running, voltmeter should indicate less than one volt. If voltmeter
reading is greater than one volt, check for open, corrosion or loose
connection in ground circuit.
Power Circuits
ECU is located near right kick panel. Turn ignition on. Check
for battery voltage on ECU terminals No. 102 and 107. If battery
voltage is not present, check operation of MPI control relay. See
RELAYS under MOTORS, RELAYS & SOLENOIDS.
ENGINE SENSORS & SWITCHES
BAROMETRIC PRESSURE SENSOR
Sensor is a component part of airflow sensor assembly. See G
- TESTS W/CODES article in the ENGINE PERFORMANCE Section.
COOLANT TEMPERATURE SENSOR
1) Remove coolant temperature sensor located near thermostat
housing (2-wire connector). Place end of sensor in water with terminal\

connector portion of sensor slightly above water.
2) Gradually heat water and read resistance values across
terminal connectors. See COOLANT TEMPERATURE SENSOR RESISTANCE table.
If resistance is not within specification, replace sensor.
COOLANT TEMPERATURE SENSOR RESISTANCE TABLE









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TemperatureF (C) Ohms
Montero & Pickup 3.0L
32 (0) ............................. 5900
68 (20) ............................ 2500
104 (40) ........................... 2700
176 (80) ............................ 300
All Others
32 (0) ............................. 5900
68 (20) ............................ 2500
104 (40) ........................... 1100
176 (80) ............................ 300









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CRANK ANGLE SENSOR
See IGNITION SYSTEM.
DETONATION SENSOR
See IGNITION SYSTEM.
EGR TEMPERATURE SENSOR
California
See EXHAUST GAS RECIRCULATION (EGR) under EMISSION SYSTEMS &
SUB-SYSTEMS.
IDLE POSITION SWITCH
NOTE: Idle position switch is incorporated in idle speed control
motor assembly, motor position sensor or throttle position
sensor, depending upon vehicle application.
Pickup 2.4L & Ram-50 2.4L
1) Disconnect motor position sensor (MPS) connector. Connect\
ohmmeter lead between ground and MPS connector terminal No. 4. See
Fig. 2 .
2) With accelerator pedal pressed, no continuity should be
present. With accelerator pedal released, continuity should be
present. If switch continuity is not as specified, replace MPS.
Montero, Pickup 3.0L & Ram-50 3.0L
1) Disconnect throttle position sensor (TPS) connector.
Connect ohmmeter between TPS connector terminals No. 1 and 2. See
Fig. 6 .
2) With accelerator pedal pressed, no continuity should be
present. With accelerator pedal released, continuity should be
present. If idle switch continuity is not as specified, replace TPS.
INHIBITOR SWITCH
Automatic Transmission
Switch is mounted to automatic transaxle, near shift lever

mechanism. Testing information is not available from manufacturer. See
appropriate wiring diagram in L - WIRING DIAGRAMS article in the
ENGINE PERFORMANCE Section.
INTAKE AIR TEMPERATURE SENSOR
1) Sensor is incorporated in airflow sensor assembly inside
air filter housing. Disconnect airflow sensor connector. See Fig. 1.
Fig. 1: Airflow Sensor Connector Terminal ID
Courtesy of Mitsubishi Motor Sales of America.
2) Measure resistance between terminals No. 4 and 6 of
airflow sensor connector (sensor side of connector). For
specifications, see INTAKE AIR TEMPERATURE SENSOR RESISTANCE table.
Replace airflow sensor assembly if air temperature sensor resistance
is not within specification.

INTAKE AIR TEMP SENSOR RESISTANCE TABLE








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TemperatureF (C) Ohms
All Models
32 (0) ........................ 6000
68 (20) ....................... 2700
176 (80) ....................... 400









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MOTOR POSITION SENSOR
NOTE: Some engines are not equipped with Motor Position Sensor
(MPS). MPS may be a separate unit mounted to throttle body
or it may be incorporated in ISC motor assembly, depending
upon vehicle application.
Pickup 2.4L & Ram-50 2.4L
1) Disconnect MPS connector. See Fig. 2. Connect ohmmeter
lead to ground. Connect other ohmmeter lead to terminal No. 3 of
sensor connector. If continuity is not present, repair wiring harness
as necessary. If continuity is present, go to next step.
Fig. 2: Motor Pos. Sensor Connector Term. ID
Courtesy of Mitsubishi Motor Sales of America.
2) Connect ohmmeter leads to terminals No. 2 and 3.
Resistance should be 4000-6000 ohms. If resistance is not within

specified range, replace MPS.
CAUTION: DO NOT apply more than 6 volts to ISC motor.
3) Operate ISC motor by connecting a 6-volt source directly
to appropriate terminals of ISC motor connector. For ISC motor
operation test procedures, see IDLE SPEED CONTROL (ISC) MOTOR
OPERATION TEST under IDLE CONTROL SYSTEM.
4) While operating ISC motor, measure resistance between MPS
connector terminals No. 3 and 5. Observe ohmmeter during ISC motor
operation. If MPS resistance does not vary within a 4000-6000 ohm
range or if resistance does not change smoothly, replace MPS (vehicles
equipped with separate MPS) or ISC motor assembly (vehicles equipped
with MPS incorporated in ISC).
OXYGEN SENSOR
1-Wire Or 2-Wire
1) On all models, warm engine until coolant temperature is
185-205
F (85-96C). Disconnect oxygen sensor connector. See Fig. 3 or
4.
2) Connect digital voltmeter between terminal No. 1 and
ground. Repeatedly race engine and observe oxygen sensor output
voltage. If output is not 0.6-1.0 volt, replace oxygen sensor.
Fig. 3: O2 Sensor Connector Terminal ID (1 Wire)
Courtesy of Mitsubishi Motor Sales of America.

Fig. 4: O2 Sensor Connector Terminal ID (2 Wire)
Courtesy of Mitsubishi Motor Sales of America.
4-Wire Heated
1) Warm engine until coolant temperature is 185-205
F (85-