1998 MITSUBISHI MONTERO ABS

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.

ANTI-LOCK BRAKE SAFETY PRECAUTIONS
1998 Mitsubishi Montero
GENERAL INFORMATION
Anti-Lock Brake Safety Precautions
* PLEASE READ THIS FIRST *
This article is intended for general information purposes
only. This information may not apply to all makes and models. If
vehicle is equipped with Anti-Lock Brake System (ABS), refer to
appropriate ANTI-LOCK BRAKE SYSTEM article in the BRAKES section for
description, operation, depressurizing, testing, system bleeding,
trouble shooting and servicing of specific system.
WARNING: Failure to depressurize ABS could lead to physical injury.
ANTI-LOCK BRAKE SAFETY PRECAUTIONS
WARNING: Failure to depressurize ABS could lead to physical injury.
* NEVER open a bleeder valve or loosen a hydraulic line
while ABS is pressurized.
* NEVER disconnect or reconnect any electrical connectors
while ignition is on. Damage to ABS control unit may result.
* DO NOT attempt to bleed hyudarulic system without first
referring to the appropriate ANTI-LOCK BRAKE SYSTEM article
in the BRAKES section.
* Only use specially designed brake hoses/lines on ABS equipped
vehicles.
* DO NOT tap on speed sensor components (sensor, sensor rings).
Sensor rings must be pressed into hubs, NOT hammered into
hubs. Striking these components can cause demagnetization or
a loss of polarization, affecting the accuracy of the speed
signal returning to the ABS control unit.
* DO NOT mix tire sizes. Increasing the width, as long as tires
remain close to the original diameter, is acceptable. Rolling
diameter must be identical for all 4 tires. Some
manufacturers recommend tires of the same brand, style and
type. Failure to follow this precaution may cause inaccurate
wheel speed readings.
* DO NOT contaminate speed sensor components with grease. Only
use recommended coating, when system calls for an
anti-corrosion coating.
* When speed sensor components have been removed, ALWAYS check
sensor-to-ring air gaps when applicable. These specifications
can be found in each appropriate article.
* ONLY use rocommended brake fluids. DO NOT use silicone brake
fluids in an ABS equipped vehicle.
* When instlling transmittion devices (CB's, telephones, etc.)
on ABS equipped vehicles, DO NOT locate the antenna near the
ABS control unit (or any control unit).
* Disconnect all on-board computers, when using electric
welding equipment.
* DO NOT expose the ABS control unit to prolonged periods of
high heat (185
F/85C for 2 hours is generally considered a
maximum limit).

ANTI-LOCK BRAKE SYSTEM
1998 Mitsubishi Montero
1997-98 BRAKES
Mitsubishi - Anti-Lock
Montero
DESCRIPTION
CAUTION: See ANTI-LOCK BRAKE SAFETY PRECAUTIONS article in GENERAL
INFORMATION.
NOTE: For more information on brake system, see BRAKE SYSTEM
article.
The Anti-Lock Brake System (ABS) is designed to prevent wheel\
lock-up during heavy braking. This allows operator to maintain
steering control while stopping vehicle in shortest distance possible.
Major components are a hydraulic unit, wheel speed sensors, "G"
sensor, ABS Electronic Control Unit (ECU) and ANTI-LOCK warning light.\
ABS has a self-diagnostic system to indicate a system malfunction and
for use in system trouble shooting.
OPERATION
Each wheel sensor sends an AC electrical signal to the ECU.
The ECU reads this information as wheel speed. When any decelerating
wheel speed rate is determined to be excessive in comparison to other
monitored wheels, the hydraulic unit cycles hydraulic brake pressure
to each wheel to equalize speed of all wheels. ABS turns itself off
when vehicle drops to 4 MPH. Minor lock-up may occur at this point.
With engine running and vehicle speed greater than 4 MPH,
pump motor will operate for a short period of time and may be heard
inside vehicle. During pump motor operation, ABS system is completing
a self-check. During ABS system operation, a pulsing brake pedal and
vibration in steering wheel and vehicle body may be experienced. These
conditions are normal.
BLEEDING BRAKE SYSTEM
BLEEDING PROCEDURES
CAUTION: When adding brake fluid, ensure filter is properly fitted on
reservoir tank.
ABS system is bled using conventional method. With engine
running, manually bleed system using an assistant. For bleeding order,
see BRAKE LINE BLEEDING SEQUENCE table. Ensure Load Sensing
Proportioning Valve (LSPV) is bled in sequence. Remove all air from
brake system. Refill brake fluid reservoir after bleeding procedure is
complete.
BRAKE LINE BLEEDING SEQUENCE









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Application Sequence
Montero ....................................... RR, LR, LSPV, RF, LF









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for one second, and then go out. Turn ignition switch to START
position. Warning light should come on and stay on.
2) When ignition switch is turned from START to ON position,
warning light should come on for one second, and then go out. If
warning light functions as specified, go to step 3). If warning light
does not function as specified, see appropriate trouble shooting test:
* IGNITION SWITCH IN ON POSITION (ENGINE NOT RUNNING),
ANTI-LOCK WARNING LIGHT INOPERATIVE
* AFTER ENGINE STARTS, ANTI-LOCK WARNING LIGHT REMAINS ON
* IGNITION SWITCH IN START POSITION, ANTI-LOCK WARNING LIGHT
INOPERATIVE
* IGNITION SWITCH IN ON POSITION, ANTI-LOCK WARNING LIGHT
BLINKS TWICE. IN START POSITION, LIGHT STAYS ON. WHEN
IGNITION SWITCH IS CYCLED FROM START TO ON POSITION, LIGHT
BLINKS ONCE, THEN TURNS OFF
3) Test drive vehicle. If ANTI-LOCK warning light does not
come on at low speed, go to next step. If light comes on at low speed,
motor relay, solenoid valve or Wheel Speed Sensor (WSS) malfunction is\
indicated. Go to step 6). If insufficient braking force or ABS
malfunction exists, go to next step. If none of listed symptoms exist,
go to step 6).
4) Check conventional brake system components for proper
operation. Check for mechanical lock of hydraulic unit solenoid valve.
Check for plugged hydraulic line in hydraulic unit. Repair or replace
as necessary. If hydraulic unit is okay, go to next step.
5) Ensure WSS rotor gap is correct. See WHEEL SPEED SENSOR
(WSS) under ADJUSTMENTS. Check for faulty wheel speed sensor. See
WHEEL SPEED SENSOR (WSS) under COMPONENT TESTS. Replace sensor as
necessary. See WHEEL SPEED SENSOR (WSS) under REMOVAL & INSTALLATION.
Inspect ECU connectors and related wiring harness. See WIRING DIAGRAMS
. If testing indicates no mechanical or electrical failures,
substitute ECU with known-good unit and retest.
6) Enter ABS self-diagnostics and retrieve Diagnostic Trouble
Codes (DTCs). See RETRIEVING DTCs under SELF-DIAGNOSTIC SYSTEM. If no
DTCs are displayed, fault may be intermittent. Attempt to make
malfunction reoccur. If no diagnostic output exists, check and repair
wiring harness between ECU and data link connector. See
WIRING DIAGRAMS .
NOTE: Trouble shoot ANTI-LOCK warning light in following sequence:
instrument cluster circuit, ECU and valve relay.
Ignition Switch In ON position (Engine Not Running),
ANTI-LOCK Warning Light Inoperative
1) If all other warning lights come on with ignition on, go
to step 3). If other warning lights do not come on, check fuse No. 11
in main fuse panel. If fuse is blown, correct cause of blown fuse, and
replace fuse. If fuse is okay, go to next step.
2) Remove instrument cluster. Turn ignition on. Using DVOM,
check voltage between vehicle ground and instrument cluster ANTI-LOCK
warning light terminal No. 28. See Fig. 2. If light does not come on,
go to next step. If light comes on, check and repair connectors and
related wiring harness between instrument cluster, ABS valve relay and
ECU. See WIRING DIAGRAMS .
3) Turn ignition off. Check for faulty warning light bulb.
Replace bulb as necessary. If bulb is okay, check and repair
connectors and related wiring harness between instrument cluster and
ECU. See WIRING DIAGRAMS . If connectors and wiring are okay, replace
instrument cluster.

Fig. 2: Identifying Instrument Cluster Connector Terminals
Courtesy of Mitsubishi Motor Sales of America.
After Engine Starts, ANTI-LOCK Warning Light Remains On
1) With ignition on, disconnect instrument cluster
connectors. If warning light remains on, replace instrument cluster.
If warning light goes off, go to next step.
2) Disconnect ECU 22-pin connector and ABS relay box 8-pin
connector. See Fig. 3. If warning light goes off, replace ECU. If
warning light stays on, check and repair connectors and related wiring
harness between ECU, instrument cluster, and ABS valve relay. See
WIRING DIAGRAMS .
Fig. 3: Exploded View Of Hydraulic Unit & Components
Courtesy of Mitsubishi Motor Sales of America.
Ignition Switch In START Position, ANTI-LOCK Warning Light
Inoperative

1) Inspect ABS relay box. See Fig. 3. Replace ABS relay box
if needed. If ABS relay box is okay, go to next step.
2) Disconnect ECU 22-pin connector and ABS relay box 8-pin
connector. Turn ignition on. Using a DVOM, check voltage between ABS
relay box 8-pin harness connector terminal No. 5 and ground. See
Fig. 4 . If battery voltage does not exist, go to next step. If battery
voltage exists, check and repair connectors and related wiring harness
between ABS valve relay and ground. See WIRING DIAGRAMS.
3) Check and repair connectors and related wiring harness
between instrument cluster and ABS valve relay. See WIRING DIAGRAMS.
Fig. 4: Identifying ABS Relay Box Connector Terminals
Courtesy of Mitsubishi Motor Sales of America.
Ignition Switch In ON Position, ANTI-LOCK Warning Light
Blinks Twice. In START Position, Light Stays On. When
Ignition Switch Is Cycled From START To ON Position, Light
Blinks Once
1) Disconnect ABS relay box connectors. See Fig. 3.
Disconnect ECU 22-pin connector. Turn ignition on. Check voltage
between ECU connector terminal No. 50 and ground. See Figs. 5-6. If
battery voltage is not present, check and repair connectors and
related wiring harness between instrument cluster and ECU. See
WIRING DIAGRAMS . If battery voltage is present, go to next step.
2) Check and repair ECU 22-pin connector. If connector is
okay, replace ECU.

Fig. 5: Identifying ECU Harness Connector Terminals 22-Pin Connector
Courtesy of Mitsubishi Motor Sales of America.
Fig. 6: Identifying ECU Harness Connector Terminals 26-Pin Connector
Courtesy of Mitsubishi Motor Sales of America.
SELF-DIAGNOSTIC SYSTEM
RETRIEVING DTCs
Using Scan Tool
1) With ignition off, connect scan tool and ROM Pack to Data
Link Connector (DLC) located under driver's side of dash, and to
cigarette lighter socket. See Fig. 7.
2) Turn ignition on. ANTI-LOCK warning light should come on
as ABS goes into self-diagnostic mode. Read and record all Diagnostic
Trouble Codes (DTCs) from ECU memory. Refer to scan tool
manufacturer's instructions for specific DTC retrieval procedure.
3) After all of the DTCs have been retrieved and recorded,
clear codes from ECU memory. Refer to scan tool manufacturer's
instructions for specific DTC clearing instructions. Refer to DTC
DEFINITION under SELF-DIAGNOSTIC SYSTEM . Refer to the appropriate DTC
under DIAGNOSTIC TESTS .
4) If DTCs cannot be cleared, ECU is currently detecting a
malfunction. If codes can be cleared, problem is either intermittent
or only appears while driving.

NOTE: DTC is set if ECU detects stoplight switch stays on for 15
minutes or more, or an open circuit in stoplight switch
system.
1) Check if stoplights are functioning correctly. If
stoplights function correctly, go to next step. If stoplights do not
function correctly, check and repair stoplight circuit. See
WIRING DIAGRAMS.
2) Turn ignition off. Disconnect ECU 22-pin connector. Using
DVOM, measure voltage between ECU 22-pin connector terminal No. 34 and
ground while depressing brake pedal. See Figs. 5-6. If battery voltage
is present, go to next step. If battery voltage is not present, check
and repair connectors and related wiring harness between stoplight
switch and ECU. See WIRING DIAGRAMS.
3) Check and repair ECU 22-pin connector. If connector is
okay, replace ECU.
DTC 41, 42 OR 43: SOLENOID VALVE CIRCUIT
NOTE: DTC sets if ECU senses that solenoid is on with no power
supplied, or off with power supplied.
1) Disconnect hydraulic unit connectors. Using ohmmeter,
check resistance between hydraulic unit connectors terminals No. 4 and
12, 5 and 12, and 6 and 12. See Fig. 11. Resistance should be 4.04-4.
54 ohms. If resistance is as specified, go to next step. If resistance
is not as specified, replace faulty hydraulic unit. See HYDRAULIC UNIT
under REMOVAL & INSTALLATION .
2) Check resistance between hydraulic unit connectors
terminals No. 1 and 12, 2 and 12, and 3 and 12. Resistance should be
8.04-8.59 ohms. If resistance is as specified, go to next step. If
resistance is not as specified, replace faulty hydraulic unit. See
HYDRAULIC UNIT under REMOVAL & INSTALLATION .
3) Turn ignition off. Disconnect ECU connectors. Check
continuity of each circuit between ECU connectors and hydraulic unit
connectors. See WIRING DIAGRAMS. If continuity exists, go to next
step. If continuity does not exist, check and repair connectors and
related wiring harness between ECU and hydraulic unit. See
WIRING DIAGRAMS .
4) Check continuity between hydraulic unit connector terminal
No. 12 and ABS relay box terminal No. 1. See Figs. 4 and 11. If
continuity exists, go to next step. If continuity does not exist,
check and repair connectors and related wiring harness between
hydraulic unit and ABS relay box. See WIRING DIAGRAMS.
5) Check and repair ECU connectors. If connectors are okay,
replace ECU.
Fig. 11: Identifying Hydraulic Unit Connector Terminals
Courtesy of Mitsubishi Motor Sales of America.
DTC 51: VALVE RELAY