1998 MITSUBISHI MONTERO indicator switch

mm Millimeters 

M/T Manual Transaxle or Transmission 

MA PFI Mass Air Sequential Port Fuel Injection system 

MA or MAF Mass Airflow 

MAF Mass Air Flow sensor 

MAFS Mass Airflow Sensor 

MAP Manifold Absolute Pressure sensor 

MAT Manifold Air Temperature 

MCU Microprocessor Control Unit 

MCV Mixture Control Valve 

MEM-CAL Memory Calibration Chip 

MFI Multiport Fuel Injection 

MIL Malfunction Indicator Light 

MLP Manual Lever Position 

MPFI Multi Point Fuel Injection 

MPH Miles Per Hour 

MPI Multi-Point (Fuel) Injection 

Man. Manual 

Mech. Mechanical 

Mem. Memory 

Mtr. Motor 











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"N" ABBREVIATION TABLE
"N" ABBREVIATION TABLE







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ABBREVIATION DEFINITION 










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N.m Newton-Meter 

NA Not Available 

NDS Neutral Drive Switch 

NGS Neutral Gear Switch 

NOx Oxides of Nitrogen 

NPS Neutral Pressure Switch 

No. Number 

Nos. Numbers 











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"O" ABBREVIATION TABLE
"O" ABBREVIATION TABLE







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ABBREVIATION DEFINITION 










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O Oxygen 

O.D. Outside Diameter 

O/S Oversize 

O2 Oxygen 

OC Oxidation Catalyst 

OCC Output Circuit Check 

OD Overdrive 

ODO Odometer 

OHC Overhead Camshaft 

ORG Orange 

OSC Output State Check 

Opt. Option or Optional 

oz. Ounce 

ozs. Ounces 











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RVB Rear Vacuum Break 

RWAL Rear Wheel Anti-Lock Brake 

RWD Rear Wheel Drive 

Recirc. Recirculate or Recirculation 

Reg. Regulator 

Rly. Relay 











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"S" ABBREVIATION TABLE
"S" ABBREVIATION TABLE







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ABBREVIATION DEFINITION 










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SAW Spark Angle Word 

SBC Single Bed Converter 

SBEC Single Board Engine Controller 

SC Super Charged 

SCC Spark Control Computer 

SCS Air Suction Control Solenoid 

SDM Supplemental Restraint System Diagnostic Module 

SDU SRS Diagnostic Unit 

SEN Sensor 

SES Service Engine Soon 

SFI Sequential (Port) Fuel Injection 

SIG RTN Signal Return circuit 

SIL Shift Indicator Light 

SIR Supplemental Inflatable Restraint 

SMEC Single Module Engine Controller 

SOHC Single Overhead Cam 

SOL or Sol. Solenoid 

SPFI Sequential Port Fuel Injection 

SPK Spark Control 

SPOUT Spark Output Signal 

SRS Supplemental Restraint System (Air Bag) 

SS 3/4-4/3 Shift Solenoid circuit 

SSI Solid State Ignition 

STAR Self-Test Automatic Readout 

STI Self Test Input circuit 

STO Self-Test Output 

SUB-O2 Sub Oxygen Sensor 

Sen. or Sens. Sensor 

Sol. Solenoid 

Sprchg. Supercharger 

Strg. Steering 

Susp. Suspension 

Sw. Switch 

Sys. System 











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"T" ABBREVIATION TABLE
"T" ABBREVIATION TABLE







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ABBREVIATION DEFINITION 










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T.V. Throttle Valve 

TAB Thermactor Air By-Pass 

TAC Thermostatic Air Cleaner 

TAD Thermactor Air Diverter 

TAN Tan 

TBI Throttle Body Injection 

2) Disconnect ECU 26-pin connector. Check resistance between
specified ECU connector terminals. See
WHEEL SPEED SENSOR OUTPUT CIRCUIT IDENTIFICATION table. See Figs. 5-6.
Resistance for front sensors should be 1170-1350 ohms. Resistance for
rear sensors should be 1300-1500 ohms. If resistance is as specified,
go to next step. If resistance is not as specified, check and repair
connectors and related wiring between ECU and suspect sensor. See
WIRING DIAGRAMS .
3) Raise and support vehicle. Disconnect ECU connectors.
Using DVOM, backprobe specified ECU connector terminals. See
WHEEL SPEED SENSOR OUTPUT CIRCUIT IDENTIFICATION table. See Figs. 5-6.
Check voltage between each harness connector terminal while rotating
wheel at 1/2 to one rotation per second. If pulse voltage is 70 mV or
more, go to step 8). If voltage is not as specified, go to next step.
4) Inspect condition of suspect speed sensor. Ensure tip of
speed sensor is clean. If speed sensor is okay, go to next step.
5) Disconnect sensor connector. Using DVOM, check resistance
across sensor terminals. Resistance for front sensors should be 1170-
1350 ohms. Resistance for rear sensors should be 1300-1500 ohms. If
resistance is as specified, go to next step. If resistance is not as
specified, replace sensor.
6) Remove sensor. Check resistance between each sensor
terminal and sensor body. If resistance is 100,000 ohms or more, go to
next step. If resistance is not as specified, replace sensor.
7) Inspect condition of toothed rotor. Check for broken or
deformed teeth. If toothed rotor is okay, go to next step.
8) Check ECU connectors. Repair connectors as needed. If
connectors are okay, replace ECU.
DTC 25: FREE WHEEL ENGAGE SWITCH
NOTE: DTC sets if ECU detects an open circuit in free wheel engage
switch.
1) Start engine. Ensure 4WD indicator light operates
correctly when transfer shift lever is moved to desired 4WD positions.
If indicator light operates correctly, go to step 3). If indicator
light does not operate correctly, go to next step.
2) Turn engine off. Check wiring harness between 4WD
indicator control unit (located behind radio) and free wheel engage
switch (located on right side of front differential housing, near
carrier assembly). If circuit is okay, replace 4WD indicator control
unit.
3) Disconnect ECU 22-pin connector. Turn ignition on. Using
DVOM, check voltage between ECU 22-pin connector terminal No. 45 and
ground. See Figs. 5-6. In 2WD, battery voltage should exist. Battery
voltage should not exist in 4WD. If voltage is as specified, go to
next step. If voltage is not as specified, check and repair connectors
and wiring harness between free wheel engage switch and ECU. See
WIRING DIAGRAMS .
4) Check and repair ECU 22-pin connector. If connector is
okay, replace ECU.
DTC 26: CENTER DIFFERENTIAL LOCK DETECTION SWITCH
NOTE: DTC sets if ECU detects an open circuit in center
differential lock detection switch system.
1) Start engine. Ensure 4WD indicator light operates
correctly when transfer shift lever is moved to desired 4WD positions.
If indicator light does not operate correctly, go to step 4). If
indicator light operates correctly, go to next step.
2) Disconnect ECU 22-pin connector. Turn ignition on. Using

DVOM, check voltage between ECU 22-pin connector terminal No. 35 and
ground. See Figs. 5-6. Battery voltage should exist in 4WD. Go to next
step.
3) If voltage is not as specified, check and repair
connectors and wiring harness between center differential lock
detection switch and ECU. See WIRING DIAGRAMS. Center differential
lock detection switch is located on side of transfer case. See Fig. 9.
If voltage is as specified, check and repair ECU 22-pin connector. If
connector is okay, replace ECU.
Fig. 9: Identifying 4WD Indicator Switch Location
Courtesy of Mitsubishi Motor Sales of America.
NOTE: When checking for short in ECU circuit, remove ECU connector
and ensure 4WD indicator light operates correctly. If 4WD
indicator light operates correctly, replace faulty ECU. If
4WD indicator light does not operate correctly, replace
faulty 4WD indicator control unit.
4) If no indicator lights come on, repair 4WD indicator power
circuit, or check for faulty 4WD indicator control unit. See 4WD
CONTROL UNIT under COMPONENT TESTS. If center differential light comes
on, regardless of position of transfer shift lever, check the
following:

* Check for short in center differential lock switch circuit.
* Check for faulty center differential lock switch.
* Check for short in ECU circuit or faulty ECU.
* Check for short in indicator control unit circuit or faulty
4WD indicator control unit.
Repair wiring harness or replace component as necessary. See
WIRING DIAGRAMS .
5) If 4WD indicator light does not come on with transfer
shift lever in "4H" position, repair wiring harness between 4WD
indicator control unit and center differential lock switch. Check for
faulty 4WD indicator control unit.
6) If 4WD indicator light does not come on with transfer
shift lever in "4H" position, repair wiring harness between 4WD
indicator control unit and free wheel engage switch. See
WIRING DIAGRAMS . Check ground wire at engage switch. Check for faulty
free wheel engage switch.
DTC 27: REAR DIFFERENTIAL LOCK DETECTION SWITCH (WITH
DIFFERENTIAL LOCK)
NOTE: DTC is set if ECU detects an open circuit in rear
differential lock detection switch system.
1) Start engine. Ensure rear differential indicator light
comes on when top of rear differential lock switch (located below
radio) is pushed. If indicator light comes on, go to step 3). If
indicator light does not come on, go to next step.
2) Turn engine off. Check wiring harness between rear
differential lock control unit and rear differential lock switch. See
WIRING DIAGRAMS . Check rear differential lock control unit power
circuit. See REAR DIFFERENTIAL CONTROL UNIT under COMPONENT TESTS. If
circuit is okay, replace rear differential lock control unit.
3) Disconnect ECU 22-pin connector. Turn ignition on. Using
DVOM, check voltage between terminal No. 46 and ground. See Figs. 5-6.
When rear differential is locked, battery voltage should not be
present. When rear differential is unlocked, battery voltage should be
present. If voltage is as specified, go to next step. If voltage is
not as specified, repair connectors and related wiring harness between
ECU and rear differential lock switch. See WIRING DIAGRAMS.
4) Check and repair ECU 22-pin connector. If connector is
okay, replace ECU.
DTC 27: REAR DIFFERENTIAL LOCK DETECTION SWITCH (WITHOUT
DIFFERENTIAL LOCK)
NOTE: DTC is set if ECU detects an interruption of battery voltage
at ECU terminal No. 46.
1) Check fuse No. 18 in main fuse block. If fuse is blown,
correct cause of blown fuse, and replace fuse. If fuse is okay, go to
next step.
2) Disconnect ECU 22-pin connector. Turn ignition on. Using
DVOM, check voltage between terminal No. 46 and ground. 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 ECU and fuse No. 18. See WIRING DIAGRAMS.
3) Check and repair ECU 22-pin connector. If connector is
okay, replace ECU.
DTC 32: "G" SENSOR SYSTEM
NOTE: DTC is set if ECU detects "G" sensor output voltage less

Remove radio and remove 4WD control unit. Disconnect control
unit harness connector. Backprobe harness connector. Check voltage
between each individual terminal and ground terminal No. 8 (Black
wire). See Figs. 12 and 13. If after all tests have been completed
system is not operating properly, substitute 4WD control unit with
known-good unit and retest.
Fig. 12: Identifying 4WD Control Unit Connector
Courtesy of Mitsubishi Motor Sales of America.
Fig. 13: 4WD Control Unit Pin Voltage Chart
Courtesy of Mitsubishi Motor Sales of America.
4WD INDICATOR SWITCHES

All switches are mounted to transfer case. See Fig. 9.
Switches use single harness lead and ground to transfer case. See 4WD
INDICATOR SWITCH CONTINUITY CHECK table. Ensure all appropriate
grounding straps are connected to vehicle body or frame.
4WD INDICATOR SWITCH CONTINUITY CHECK









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Switch Transfer Control Lever Position Specification
Center Differential Lock
Detection Switch .............. 4H ................. No Continuity
Detection Switch ............. 4HLc ................... Continuity
Center Differential Lock
Operation Detection Switch .. 4H .................. No Continuity
" ........................... 4HLc .................... Continuity
4WD Operation
Detection Switch .............. 2H ................. No Continuity
Detection Switch .............. 4H .................... Continuity
HI/LO Detection Switch ...... 4HLc .................... Continuity
" ............................. N .................. No Continuity
" ........................... 4LLc .................... Continuity
2WD/4WD
Detection Switch ............ 2H .................... Continuity
" ........................... 4H ................. No Continuity









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REAR DIFFERENTIAL CONTROL UNIT
Remove rear seat and remove rear differential control unit.
Do not disconnect control unit harness connector. Backprobe harness
connector. Check voltage between each individual terminal and ground
terminal No. 6 (Black wire). See Figs. 14 and 15. If after all tests
have been completed system is not operating properly, substitute rear
differential control unit with known good-unit and retest.
Fig. 14: Identifying Rear Differential Control Unit Connector
Courtesy of Mitsubishi Motor Sales of America.

AUTO TRANS DIAGNOSIS - R4AW3 & V4AW3
1998 Mitsubishi Montero
1997-98 AUTOMATIC TRANSMISSIONS
Mitsubishi R4AW3 & V4AW3 Electronic Controls
Montero, Montero Sport
APPLICATION
TRANSMISSION APPLICATION








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Vehicle Transmission Model
Montero Sport 2WD ............................................ R4AW3
Montero & Montero Sport 4WD .................................. V4AW3









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CAUTION: Vehicle is equipped with Supplemental Restraint System (SRS).
When servicing vehicle, use care to avoid accidental air bag
deployment. SRS-related components are located in steering
column, center console, instrument panel and lower panel on
instrument panel. DO NOT use electrical test equipment on
these circuits. If necessary, deactivate SRS before servicing
components. See AIR BAG SERVICING article in APPLICATIONS &
IDENTIFICATION.
DESCRIPTION
Automatic transmission is a 4-speed electronically controlled
transmission. Solenoids that control shift changes are located in
valve body. Solenoids are controlled by a Transmission Control Module
(TCM). TCM receives information from various input devices and uses
this information to control shift solenoids for transmission shifting
and lock-up solenoid for torque converter lock-up.
An Overdrive (OD) switch is mounted on the shift lever. When
OD switch is depressed to ON position, transmission will shift into
4th gear when shift lever is in "D" position, and OD OFF light on
instrument panel will go off. When OD switch is released to OFF
position, transmission will shift into 3rd gear, and OD OFF light on
instrument panel will illuminate.
A pattern select switch is located near shift lever on center
console. Pattern select switch contains a NORMAL and a HOLD operating
position. When pattern select switch is depressed (HOLD position) with\
shift lever in Drive position, transmission starts in 2nd gear.
Upshifts and downshifts will occur at a higher vehicle speed than with
switch in NORMAL position. See MITSUBISHI R4AW3 & V4AW3 OVERHAUL
article. Indicator light on instrument panel indicates pattern select
switch is in HOLD position.
Transmission is equipped with a shift lock and key interlock
system. Shift lock system prevents shift lever from being moved from
Park unless brake pedal is depressed. Key interlock system prevents
ignition key from being moved from ACC to LOCK position on ignition
switch unless shift lever is in Park. See MITSUBISHI SHIFT LOCK
SYSTEMS article.
OPERATION
TCM
TCM receives information from various input devices and uses