1998 MITSUBISHI MONTERO sensor

ADJUSTMENTS
NOTE: For adjustment procedures, see HEATER SYSTEM article.
TROUBLE SHOOTING
NO COOLING
1) Ensure compressor clutch is operating. If compressor
clutch is operating, go to next step. If compressor clutch is not
operating, check fuses and A/C switch. Check dual-pressure switch.
Check air inlet sensor and air thermosensor. Check A/C compressor
relay. Check A/C compressor clutch coil. Check A/C control unit.
2) Ensure system is properly charged with correct amount of
refrigerant. Evacuate and charge system as necessary. Ensure receiver-
drier is not clogged. Check compressor belt for proper tension. Check
for clogged expansion valve. Check compressor operation. Repair or
replace components as necessary.
INSUFFICIENT AIRFLOW
Check for air leakage at air duct joint. Check for frost on
evaporator. Ensure blower motor is operating properly. Check for
obstructed air intake.
INSUFFICIENT COOLING
Ensure system is properly charged with correct amount of
refrigerant and free of air and moisture. Evacuate and charge system
as necessary. Ensure receiver-drier is not clogged. Ensure sufficient
airflow through condenser exists. Check compressor belt for proper
tension. Check compressor operation. Repair or replace compressor as
necessary. Check for clogged expansion valve. Replace expansion valve
as necessary. Check A/C compressor clutch coil.
INTERMITTENT COOL AIR
Check for air or moisture in system. Evacuate and charge
system as necessary. Check for expansion valve malfunction. Replace
expansion valve if necessary. Check compressor belt for proper
tension.
TESTING
* PLEASE READ THIS FIRST *
WARNING: To avoid injury from accidental air bag deployment, read and
carefully follow all SERVICE PRECAUTIONS and DISABLING &
ACTIVATING AIR BAG SYSTEM procedures in AIR BAG RESTRAINT
SYSTEM article.
NOTE: For testing procedures not covered in this article, see
HEATER SYSTEM article.
A/C SYSTEM PERFORMANCE
1) Park vehicle out of direct sunlight. Install A/C gauge
set. Start engine and allow it to idle at 1000 RPM. Turn A/C on. Set
A/C controls to recirculated air, panel (vent) mode and full cold

settings.
2) Set blower/fan on high speed. Close doors and windows.
Insert thermometer in center vent. Operate system for 20 minutes to
allow system to stabilize. Measure temperature.
3) Discharge air temperature must be 37-44
F (3-7C) at
center vent, with high side and low side pressures within
specification. See A/C SYSTEM SPECIFICATIONS table at beginning of
article.
A/C CONTROL UNIT (ACCU)
1) Locate A/C Control Unit (ACCU) on top of evaporator case
and disconnect 10-pin connector. Inspect connector and wiring for
damage. Turn ignition and A/C on. Set temperature control to maximum
cooling and blower switch to high. Using a DVOM set to appropriate
test function, inspect harness side of connector. See Fig. 3. Go to
next step. If all test readings are as specified, replace ACCU.
2) Terminal No. 1 (Green/Yellow wire) is ACCU output. With
A/C and blower motor on, battery voltage should be present when ACCU
has received signals from pressure and temperature sensors confirming
A/C operation is okay.
3) Terminal No. 3 (Green/Blue wire) is ACCU power supply whe\
n
A/C switch is in A/C mode. With ignition and blower on, and A/C switch
at second level setting, battery voltage should be present.
4) Terminal No. 5 (Green/Red wire) is ACCU power supply when\
A/C switch is in ECONO mode. With ignition and blower on, and A/C
switch at first level setting, battery voltage should be present.
Terminals No. 2 and 7 (Black wire) are ACCU grounds. There should be
zero volts at all times.
5) Turn ignition off. Reconnect 10-pin connector. Turn
ignition on. Turn A/C on. Set temperature control to maximum cooling
and blower switch to high. Backprobe 10-pin connector. Go to next
step. If all test readings are as specified, replace ACCU.
6) Terminal No. 10 (Blue/White wire) is air thermosensor
power supply. With ignition, blower and A/C on, approximately 5.5
volts should be present.
7) Terminal No. 8 (Blue/Yellow wire) is air thermosensor
signal. When temperature of evaporator outlet portion is 77
F (25C),
there should be approximately 3.6 volts present.
8) Terminal No. 4 (White/Blue wire) is air inlet sensor powe\
r
supply. With ignition, blower and A/C on, approximately 5.5 volts
should be present.
9) Terminal No. 9 (Yellow/Green wire) is air inlet sensor
signal. When temperature of evaporator outlet portion is 77
F (25C),
there should be approximately 1.5 volts present.
Fig. 1: Testing ACCU
Courtesy of Mitsubishi Motor Sales of America.
A/C SWITCH

Fig. 3: Testing A/C Engine Coolant Temperature Switch
Courtesy of Mitsubishi Motor Sales of America.
AIR THERMOSENSOR & AIR INLET SENSOR
1) Disconnect sensor connector at evaporator case. See
Fig. 12 . Using ohmmeter, measure resistance between sensor terminals.
See AIR THERMOSENSOR & AIR INLET SENSOR SPECIFICATIONS table.
2) If resistance is not within specifications, faulty sensor
must be replaced. If resistance is within specifications and all other
components are okay, replace A/C Compressor Control Unit (ACCU).
AIR THERMOSENSOR & AIR INLET SENSOR SPECIFICATIONS TABLE









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Sensor Temperature F (C) Ohms
-20 (-4) .......................................... 12,000
32 (0) .............................................. 4800
50 (10) ............................................. 2800
68 (20) ............................................. 1800
86 (30) ............................................. 1000
104 (40) ............................................. 800









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BLOWER RESISTOR
Disconnect blower resistor connector. Using an ohmmeter,
measure resistance between indicated terminals. See BLOWER RESISTOR
RESISTANCE table. See Fig. 4
BLOWER RESISTOR RESISTANCE TABLE

Fig. 13: Exploded View Of Evaporator Assembly
Courtesy of Mitsubishi Motor Sales of America.
REFRIGERANT TEMPERATURE SENSOR

Removal & Installation
Discharge A/C system, using approved refrigerant
recovery/recycling equipment. Disconnect refrigerant temperature
sensor wiring connector. Remove temperature sensor from compressor. To
install, reverse removal procedure. Use new "O" ring on temperature
sensor.
TORQUE SPECIFICATIONS
TORQUE SPECIFICATIONS TABLE








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Application Ft. Lbs. (N.m)
A/C Compressor Bolt/Nut .................... 17-20 (23-27)
A/C Compressor Bracket Bolt/Nut .................. 37 (50)
A/C Compressor Clutch Coil Nut ................... 12 (16)
A/C Engine Coolant Temperature Switch ............ 26 (35)
INCH Lbs. (N.m)
Blower Motor Bolts/Nuts ........................... 44 (5)
Condenser Bolts/Nuts ............................ 106 (12)
Dual-Pressure Switch ............................. 89 (10)
Evaporator Assembly Bolts/Nuts .................... 44 (5)
Heater Assembly Bolts/Nuts ........................ 44 (5)









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WIRING DIAGRAMS

AIR BAG RESTRAINT SYSTEM
1998 Mitsubishi Montero
1998 AIR BAG RESTRAINT SYSTEMS
Mitsubishi
Montero
DESCRIPTION & OPERATION
WARNING: To avoid injury from accidental air bag deployment, read and
carefully follow all WARNINGS and SERVICE PRECAUTIONS.
Supplemental Restraint System (SRS) consists of an SRS
warning light, driver-side and passenger-side air bag module,
clockspring, right and left front impact sensors, and SRS Air Bag
Control Unit (ECU). The SRS-ECU contains an analog and a safing impact\
sensor. See Fig. 1.
Air bags are designed to deploy in a frontal or near frontal
impact of moderate to severe force. For air bags to deploy, ignition
must be on and safing impact sensor and at least one front impact
sensor must activate simultaneously.
Fig. 1: Locating SRS Components
Courtesy of Mitsubishi Motor Sales of America.
SRS WARNING LIGHT

When ignition switch is turned to ON or START position, SRS
warning light on instrument panel should come on for about 7 seconds
and then go off. This indicates SRS-ECU has determined SRS is
functioning properly. If SRS warning light flashes, stays on all the
time, or does not come on, a fault exists in SRS. See
DIAGNOSIS & TESTING.
FRONT IMPACT SENSORS
Sensors are inertia switches that verify direction and
severity of impact. If impact is great enough, switch contacts close,
completing an electrical circuit. Front impact sensors are located
under front fenders. See Fig. 1.
AIR BAG MODULE(S)
An inflator assembly in the air bag module produces nitrogen
gas to fill air bag. See Fig. 1. When a small amount of current from
SRS-ECU is applied, ignitor starts a thermal reaction, which spreads
to a pellet-filled canister that produces nitrogen gas. Gas pressure
builds and discharges from inflator through a diffuser and screen
assembly, forcing trim cover to burst along its seams until air bag is
fully inflated. When air bag is fully inflated, gas escapes through
vents on sides of air bag.
SRS AIR BAG CONTROL UNIT (ECU)
SRS-ECU (with integral safing and analog impact sensor) is
located behind front floor console assembly. See Fig. 1. If a system
fault occurs, SRS-ECU memory stores a diagnostic trouble code (DTC).
DATA LINK CONNECTOR (DLC)
DLC is located under left side of dash. See Fig. 1. DLC is
used to access SRS self-diagnostics through Mitsubishi Multi-Use
Tester II (MUT-II) (MB991502).
CLOCKSPRING
Clockspring connects driver-side air bag module to steering
column wiring, forming SRS circuit. See Fig. 1. Clockspring is a flat,
ribbon-like cable that winds and unwinds when steering wheel is
turned. Because of clockspring's constant movement, it is the most
fragile part in the system.
SYSTEM OPERATION CHECK
WARNING: After servicing, always turn ignition on from passenger-side
of vehicle in case of accidental air bag deployment.
Turn ignition switch to ON position. SRS warning light on
instrument panel should come on for about 7 seconds and then turn off.
This indicates SRS is functioning properly. If SRS warning light does
not come on, stays on, or comes on while driving, SRS is
malfunctioning and needs repair. See DIAGNOSIS & TESTING.
SERVICE PRECAUTIONS
Observe the following precautions when working with SRS:
* Disable SRS before servicing any SRS or steering column

component. Failure to do this may result in accidental air
bag deployment and possible personal injury. Refer to
DISABLING & ACTIVATING AIR BAG SYSTEM .
* For about 60 seconds after air bag system is disabled, it
retains enough voltage to deploy air bags. After disabling
system, wait at least 60 seconds before servicing.
* After servicing, always turn ignition on from passenger-side
of vehicle in case of accidental air bag deployment.
* After servicing, check SRS warning light to verify system
operation. See SYSTEM OPERATION CHECK.
* Always wear safety glasses when servicing or handling an
air bag.
* The SRS-ECU must be stored in its original special container
until used for service. It must be stored in a clean, dry
place, away from sources of extreme heat, sparks and high
electrical energy.
* DO NOT expose air bag module and clockspring to temperatures
greater than 200
F (93C).
* When placing a live air bag module on a bench or other
surface, always face air bag module and trim cover up, away
from surface. This will reduce motion of module if air bag
accidentally deploys.
* After air bag deploys, air bag surface may contain deposits
of sodium hydroxide, which irritates skin. Always wear
safety glasses, rubber gloves and long-sleeved shirt during
clean-up. Wash hands using mild soap and water. Follow
correct clean-up and disposal procedures. Refer to
DISPOSAL PROCEDURES .
* Because of critical system operating requirements, DO NOT
service any SRS components. Repairs are only made by
replacing defective part(s).
* DO NOT allow any electrical source near inflator on the back
of air bag module.
* When carrying a live (undeployed) air bag module, trim cover
must be pointed away from body to minimize injury in case of
accidental air bag deployment.
* DO NOT probe wire harness connector terminals. Instead, use
SRS Check Harness (MB991530).
* DO NOT probe a wire through insulator, as this will damage
it and eventually cause failure due to corrosion.
* When performing electrical tests, prevent accidental
shorting of terminals. Such shorts can damage fuses or
components and may cause a second fault code to set, making
diagnosis of original problem more difficult.
* Never use an analog volt/ohm meter or test light in place of
a Digital Volt/Ohm Meter (DVOM). Use only a DVOM with a
maximum test current of 2 mA (milliamps) at minimum range of
resistance measurement. Also see SPECIAL TOOLS.
* If SRS is not fully functional for any reason, DO NOT drive
vehicle until system is repaired and is fully functional. DO
NOT remove bulbs, modules, sensors or other components, or
in any way disable system from operating normally. If SRS is
not functional, park vehicle until repairs are made.
SPECIAL TOOLS
To avoid air bag deployment when working on SRS, DO NOT use
electrical test equipment such as test lights, battery or A/C-powered
volt/ohmmeter, or any type of electrical equipment other than those
specified by manufacturer. See SRS RECOMMENDED TOOLS table.
SRS RECOMMENDED TOOLS TABLE









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