Other Means Of Identification
Refrigerant R-134a, when viewed through a sight glass, may
have a "milky" appearance due to the mixture of refrigerant and
lubricating oil. As the refrigerant and oil DO NOT exhibit a "clear"
sight glass on a properly charged A/C system, most R-134a systems have
no sight glass.
REFRIGERANT OILS
NOTE: Use ONLY the specified oil for the appropriate system or A/C
compressor. Always check vehicle underhood A/C specification
label or A/C compressor label before adding refrigerant oil
to A/C compressor/system. See Figs. 2 and 3. Always use
refrigerant oil specified on vehicle underhood A/C
specification label if different from the following list.
Refrigerant R-12 based systems use mineral oil, while R-134a
systems use Polyalkylene Glycol (PAG) oils. Using a mineral oil based
lubricant with R-134a will result in A/C compressor failure due to
lack of proper lubrication. The following R-134a refrigerant oils are
currently specified:
Use DENSO/ND-Oil 8 refrigerant oil on Nippondenso
compressors. Use SUN PAG 56 refrigerant oil on Sanden compressors.
NOTE: PAG oils absorb moisture very rapidly, 2.3-5.6 percent by
weight, as compared to a mineral oil absorption rate of
0.005 percent by weight.
SERVICE EQUIPMENT
A/C systems using R-134a refrigerant and PAG lubricants
cannot use R-12 refrigerant or mineral oil lubricants. R-134a
refrigerant is NOT compatible or interchangeable with R-12
refrigerant. Separate sets of hoses, manifold gauge sets and
recovery/recycling equipment are required to service the different
systems. This is necessary to avoid cross-contaminating and damaging
A/C system. A single set of A/C service equipment cannot be cleaned
thoroughly enough to be used with both types of refrigerant.
All equipment used to service A/C systems using R-134a must
be U.L. listed and certified to meet SAE standard J2210. The service
hoses on the manifold gauge set must have manual (turn wheel) or
automatic back-flow valves at the service port connector ends. This
will prevent refrigerant from being released into the atmosphere.
For identification purposes, R-134a service hoses must have a
Black stripe along its length and be clearly labeled SAE J2196/R-134a.
The low pressure test hose is Blue with a Black stripe. The high
pressure test hose is Red with a Black stripe, and the center test
hose is Yellow with a Black stripe.
R-134a manifold gauge sets can be identified by one or all of
the following: Labeled FOR USE WITH R-134a on set, labeled HFC-134a or
R-134a on gauge face, or by a Light Blue color on gauge face. In
addition, pressure/temperature scales on R-134a gauge sets are
different from R-12 manifold gauge sets.
SYSTEM SERVICE VALVES
SCHRADER-TYPE VALVES
NOTE: Although similar in construction and operation to a tire
valve, NEVER replace a Schrader-type valve with a tire valve.
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 (93 C).
* 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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clockspring, the steering wheel may not turn completely, or
flat cable inside clockspring may be severed, disabling SRS
system and possibly causing serious injury to driver.
Installation
1) Ensure front wheels are in straight-ahead position. Align
mating marks on clockspring. See CLOCKSPRING CENTERING under
ADJUSTMENTS. Install clockspring. To install remaining components,
reverse removal procedure. Before installing air bag module, ensure
horn switch wiring is positioned so that it will not be pinched.
2) Tighten fasteners to spec. See TORQUE SPECIFICATIONS.
Activate SRS. See DISABLING & ACTIVATING AIR BAG SYSTEM . Check AIR BAG
warning light for proper system function. SYSTEM OPERATION CHECK.
PASSENGER-SIDE AIR BAG MODULE
Removal & Installation
1) Before proceeding, see SERVICE PRECAUTIONS. Deactivate
SRS. See DISABLING & ACTIVATING AIR BAG SYSTEM .
2) Remove right-side foot shower duct and two stoppers on
either side. Remove and lower glove box. Disconnect air bag module
connector. Remove retaining bolts and passenger-side air bag module.
See Fig. 5 .
3) To install, reverse removal procedure. Tighten bolts to
specification. See TORQUE SPECIFICATIONS . Activate SRS. See procedures
under DISABLING & ACTIVATING AIR BAG SYSTEM . Check AIR BAG warning
light for proper system function. SYSTEM OPERATION CHECK.
Fig. 5: Removing Passenger-Side Air Bag Module
Courtesy of Mitsubishi Motor Sales of America.
SRS AIR BAG CONTROL UNIT (ECU)
CAUTION: SRS-ECU connector is a double-locking mechanism. DO NOT use
excessive force when disconnecting connector.
Removal & Installation
1) Before proceeding, see SERVICE PRECAUTIONS. Deactivate
SRS. See DISABLING & ACTIVATING AIR BAG SYSTEM .
2) Remove rear and front floor console assembly. Remove
switch panel and suspension control switch. Disconnect rear console
harness connector. Remove side panel A and rear console assembly.
3) Remove shift lever. Disconnect front console harness
connector and remove front console assembly. Disconnect SRS-ECU
connector. Remove mounting bolts, bracket and SRS-ECU. See Fig. 6.
4) To install, reverse removal procedure. Tighten bolts to
specification. See TORQUE SPECIFICATIONS . Activate SRS. See procedures
under DISABLING & ACTIVATING AIR BAG SYSTEM . Check AIR BAG warning
light for proper system function. SYSTEM OPERATION CHECK.
Fig. 6: Removing SRS Air Bag Control Unit (ECU)
Courtesy of Mitsubishi Motor Sales of America.
FRONT IMPACT SENSORS
Removal & Installation
1) Before proceeding, see SERVICE PRECAUTIONS. Deactivate
SRS. See DISABLING & ACTIVATING AIR BAG SYSTEM .
2) Remove components for access to front impact sensors as
necessary. See Fig. 7. Remove front impact sensor mounting bolts.
Slide Green section of connector to release lock. Push down on pawl.
Disconnect electrical connector. Remove front impact sensor.
3) To install, reverse removal procedure. Position sensor
with arrow facing toward front of vehicle. Tighten bolts to
specification. See TORQUE SPECIFICATIONS . Activate SRS. See procedures
under DISABLING & ACTIVATING AIR BAG SYSTEM . Check AIR BAG warning
light for proper system function. SYSTEM OPERATION CHECK.
Fig. 7: Locating Front Impact Sensors
Courtesy of Mitsubishi Motor Sales of America.
ADJUSTMENTS
INCH Lbs. (N.m)
Air Bag Module Bolt/Nut
Driver-Side ........................................ ( 1)
Passenger-Side ..................................... ( 1)
Clockspring Screw .................................... ( 1)
SRS-ECU (Air Bag Control Unit) Bolt ............. 43 (4.9)
( 1) - Information is not available from manufacturer.
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DIAGNOSIS & TESTING
INITIAL SRS DIAGNOSTIC PROCEDURE
WARNING: Follow air bag service precautions to prevent accidental air
bag deployment and personal injury. See SERVICE PRECAUTIONS.
NOTE: Ensure battery is fully charged. If battery voltage is too
low, SRS warning light will come on. When battery voltage is
restored to normal, light will go out. Codes remain stored
for no more than about 7 days. Codes can be stored no more
than 250 times. After servicing, reconnect negative battery
cable. Erase codes using Multi-Use Tester II (MUT-II,
MB991502). Check SRS warning light to verify system
operation. See SYSTEM OPERATION CHECK.
CAUTION: Ensure ignition is off before connecting or disconnecting
scan tool at DLC.
1) Before proceeding, follow service precautions. See
SERVICE PRECAUTIONS . Turn ignition on. If SRS warning light comes on
for about 7 seconds and turns off, SRS is functioning properly at this
time.
2) If SRS warning light does not come on, or comes on and
stays on, turn ignition switch to LOCK position. Connect scan tool to
Data Link Connector (DLC). See Fig. 9. Turn ignition on. Use scan tool
to retrieve code(s).
Fig. 9: Connecting Scan Tool To Data Link Connector (DLC)
Courtesy of Mitsubishi Motor Sales of America.
TROUBLE SYMPTOMS TABLE
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