1998 MITSUBISHI MONTERO brake

Fig. 18: Anti-Lock Brake System (ABS) Wiring Diagram (1997 Montero)\

Fig. 19: Anti-Lock Brake System (ABS) Wiring Diagram (1998 Montero)\

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

this information to control solenoids on transmission valve body. TCM
controls transmission shifting and torque converter lock-up.
TCM contains a self-diagnostic system, which will store
Diagnostic Trouble Codes (DTC) if failure or problem exists in
electronic control system. DTC can be retrieved to determine problem
area. See SELF-DIAGNOSTIC SYSTEM. TCM is located under left side of
instrument panel, left of steering column. See Fig. 1.
TCM INPUT DEVICES
Brakelight Switch Signal
Brakelight switch delivers input signal to TCM, indicating
vehicle braking. Brakelight switch is located on brake pedal support.
Cruise Control Electronic Control Unit (ECU)
Cruise control ECU delivers an input signal to control
overdrive operation in accordance with vehicle speed when cruise
control is operating. When in overdrive with cruise control on, if
vehicle speed drops 2 MPH less than the set speed, overdrive is
released to prevent reduction in vehicle speed. Once vehicle speed is
more than the set speed, overdrive function is resumed. If coolant
temperature is low, transmission will not shift into overdrive. Cruise
control ECU is located below center A/C vent, behind temperature
control panel on Montero. On Montero Sport, cruise control ECU is
located behind driver's kick panel.
Engine Coolant Temperature Sensor (ECT) Signal
Engine coolant temperature sensor delivers input signal to
TCM, indicating engine coolant temperature. Coolant temperature sensor
is located on engine.
Input & Output Shaft Speed Sensors
Sensors are magnetic pick-ups that monitor input and output
shaft speeds. AC waveforms are input to TCM by sensors. Sensors are
located on front and rear side of transmission case.
OD Switch Signal
The OD switch provides an input signal to TCM to indicate
when overdrive is selected by operator. 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 come on. The
OD switch is mounted on shift lever.
Oil Temperature Sensor Signal
Oil temperature sensor provides TCM with ATF temperature
values. TCM uses this information to control shift points for maximum
performance. If transmission oil temperature exceeds standard values,
instrument panel ATF - TEMP light will come on. Sensor is mounted to
cooler line at transmission.
Park/Neutral Position (PNP) Switch Signal
PNP switch delivers an input signal to TCM indicating shift
lever position. Switch is located on side of transmission.
Throttle Position (TP) Sensor Signal
TP sensor delivers closed throttle and variable throttle
position input signals to TCM. TP sensor is located on side of
throttle body.
4WD Low Range Detection Switch
4WD low range detection switch provides information to TCM

under COMPONENT TESTING. If lock-up solenoid is okay, go to next step.
If lock-up solenoid is bad, replace and retest system.
4) Check wiring harness and connectors between lock-up
solenoid and TCM. If wiring harness and connectors are okay, check TCC
engagement hydraulic pressure, valve body malfunction or TCC slipping.
DTC 50: TCC DISENGAGEMENT MALFUNCTION
1) Using scan tool, verify vehicle tachometer and scan tool
vehicle RPM values are identical. If tachometer values are identical,
go to next step. If tachometer values are different, test ignition
signal circuit. See DTC 21 & 22: SHORT OR OPEN IN IGNITION SIGNAL
CIRCUIT.
2) Lift and support vehicle to allow drive wheels to spin
freely. With transmission in "D" position, run engine to 1300-1900
RPM. Verify scan tool and speedometer read 31 MPH (50 km/h). If values\
are identical, go to next step. If values are different, test input
speed sensor. See DTC 31: INPUT SPEED SENSOR.
3) Check lock-up solenoid for proper operation. See SOLENOIDS
under COMPONENT TESTING. If lock-up solenoid is okay, go to next step.
If lock-up solenoid is bad, replace and retest system.
4) Check wiring harness and connectors between lock-up
solenoid and TCM. If wiring harness and connectors are okay, check
valve body malfunction or TCC sticking.
DTC 51: 1ST GEAR RATIO SIGNAL INCORRECT
1) If DTC 31 is set, go to DTC 31: INPUT SPEED SENSOR. If DTC
31 is not set and DTC 32 is set, go to DTC 32: OUTPUT SPEED SENSOR. If
neither DTC 31 nor DTC 32 is set, go to next step.
2) Test input speed sensor. See INPUT SPEED SENSOR under
COMPONENT TESTING. If resistance is as specified, go to next step. If
resistance is not as specified, replace input speed sensor and recheck
DTC. If DTC still exists, go to step 5).
3) Test output speed sensor. See OUTPUT SPEED SENSOR under
COMPONENT TESTING. If resistance is as specified, go to next step. If
resistance is not as specified, replace output speed sensor and
recheck DTC. If DTC still exists, go to step 5).
4) If referenced here from another DTC, go back to referenced
DTC. Check No. 2 one-way clutch system. See NO. 2 ONE-WAY CLUTCH in
MITSUBISHI R4AW3 & V4AW3 OVERHAUL article.
5) Check output speed sensor and No. 2 speed sensor shielding
wire. Repair as necessary. If shielding wire is okay, recheck DTC. If
DTC still exists, replace sensor rotor. If DTC still exists after
sensor rotor is replaced, check for interference noise and repair.
DTC 52: 2ND GEAR RATIO SIGNAL INCORRECT
If DTC 51 is set also, go to DTC 51: 1ST GEAR RATIO SIGNAL
INCORRECT test. If DTC 51 is not set, check 2nd brake and No. 1 one-
way clutch systems for a mechanical failure. See 2ND BRAKE and NO. 1
ONE-WAY CLUTCH in MITSUBISHI R4AW3 & V4AW3 OVERHAUL article.
DTC 53: 3RD GEAR RATIO SIGNAL INCORRECT
If DTC 51 is set also, go to DTC 51: 1ST GEAR RATIO SIGNAL
INCORRECT test. If DTC 51 is not set, check direct clutch system for a
mechanical failure. See DIRECT CLUTCH in MITSUBISHI R4AW3 & V4AW3
OVERHAUL article.
DTC 54: 4TH GEAR RATIO SIGNAL INCORRECT

If DTC 51 is set also, go to DTC 51: 1ST GEAR RATIO SIGNAL
INCORRECT test. If DTC 51 is not set, check overdrive brake for a
mechanical failure. See OVERDRIVE BRAKE in MITSUBISHI R4AW3 & V4AW3
OVERHAUL article.
SYMPTOM TROUBLE SHOOTING
NOTE: Check system using appropriate scan tool. See WIRING DIAGRAMS
for electrical schematics and COMPONENT TESTING.
COMMUNICATION WITH SCAN TOOL NOT POSSIBLE
If scan tool cannot communicate with TCM, check proper
connection with DLC. Check TCM power circuits, TCM ground circuits and
malfunctioning TCM.
SHIFT POINTS INCORRECT
If shift points are incorrect, check for DTCs. If no DTC is
present, check oil temperature sensor, pattern select switch, 4WD low
range detection switch and TCM for proper operation.
UPSHIFTS OCCUR SPONTANEOUSLY
If upshifting occurs spontaneously, check park/neutral
position switch, overdrive switch and TCM for proper operation.
TCC LOCK-UP MALFUNCTIONING
If TCC lock-up system is not operating properly, check torque
converter, valve body, lock-up switch and oil temperature switch.
COMPONENT TESTING
A/T FLUID TEMPERATURE SWITCH
1) Remove fluid temperature switch, located to rear of
neutral safety switch. Immerse switch in container of ATF up to top
threaded portion of switch. Using a DVOM, check continuity between
switch terminals. Continuity should not exist when fluid temperature
is 257
F (125C) or less.
2) When fluid is heated to 289-304F (143-151C), continuity
should exist. Replace switch if necessary. Apply thread sealant to
fluid temperature switch threads and install in transmission.
BRAKELIGHT SWITCH
1) Disconnect electrical connector from brakelight switch,
located near brake pedal. Using ohmmeter, ensure continuity exists
between terminal No. 2 (White/Red wire) and terminal No. 3 (Green
wire) with brake pedal released. Replace brakelight switch if
continuity does not exist. Continuity should not exist between
terminals No. 2 and No. 3 with brake pedal depressed.
2) If continuity does not exist, ensure brake pedal is
properly adjusted so brakelight switch has proper travel for switch
operation. If proper brakelight switch travel exists, replace
brakelight switch.
ENGINE COOLANT TEMPERATURE (ECT) SENSOR

Using a screwdriver, remove pattern select switch from
console. Switch is located at rear of selector lever, to right of
emergency brake handle. Using a DVOM, check continuity between pattern
select switch terminals No. 1 and 2, with switch in HOLD position.
Continuity should exist. With switch in POWER position, check
continuity between terminals No. 1 and 6. Continuity should exist. If
continuity is not as specified, replace switch. See Fig. 12.
Fig. 12: Identifying Pattern Select Switch Terminals
Courtesy of Mitsubishi Motor Sales of America.
SOLENOIDS
For solenoid testing, refer to the appropriate DTC under
DIAGNOSTIC TESTS. To check solenoid operation, apply battery voltage
to appropriate terminal of TCM connector and ground. Ensure operating
sound can be heard when battery voltage is connected. Replace solenoid
if operating sound cannot be heard.
THROTTLE POSITION (TP) SENSOR
For diagnostic and testing information, see appropriate SELF-
DIAGNOSTICS article in ENGINE PERFORMANCE section.
4WD LOW RANGE DETECTION SWITCH
For location and testing information on 4WD low range
detection switch, see appropriate article in AXLE SHAFTS & TRANSFER
CASES.
TCM PIN VOLTAGE CHARTS
Access TCM. See Fig. 1 or 2. Turn ignition on. Using DVOM,

backprobe TCM connector. See Fig. 13. Check voltage between designated
terminals on TCM connector and ground. See TCM TERMINAL VOLTAGE
SPECIFICATIONS table. Voltage should be as specified.
Fig. 13: Identifying TCM Terminals
Courtesy of Mitsubishi Motor Sales of America.
TCM TERMINAL VOLTAGE SPECIFICATIONS








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Terminal Circuit  Condition  Voltage 


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1  Lock-Up Solenoid Lock-Up Clutch Engaged Battery 
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1  Lock-Up Solenoid  Lock-Up Clutch  0 Volts 

  Disengaged  
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2  Back-Up Power Supply  At All Times  Battery 
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5  Brakelight Switch  Brake Pedal Depressed 0 Volts 
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5  Brakelight Switch  Brake Pedal Released  Battery 
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8  TP Sensor Throttle Closed (Idle) .3-1.0 
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8  TP Sensor  Throttle Wide Open  4.4-5.0 
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11  Neutral Safety Switch In "P" Position  Battery 
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11  Neutral Safety Switch Except In "P"  0 Volts 
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12  Ground  Engine Idling  0 Volts