TCM MITSUBISHI MONTERO 1998 User Guide

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 


No.    
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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 

connector or harness, or torque converter clutch solenoid.
DTC P0750
Shift solenoid "A" failure. Possible causes are: connector or
harness, or low-reverse solenoid.
DTC P0755
Shift solenoid "B" failure. Possible causes are: connector or
harness, or underdrive solenoid.
DTC P0760
Shift solenoid "C" failure. Possible causes are: connector or
harness, or second solenoid.
DTC P0765
Shift solenoid "D" failure. Possible causes are: connector or
harness, or overdrive solenoid.
DTC P1103
Turbocharger wastegate actuator failure. Possible causes are:
connector or harness, faulty wastegate solenoid or actuator, or vacuum
hose routing.
DTC P1104
Turbocharger wastegate solenoid failure. Possible causes are:
connector or harness, or faulty wastegate solenoid.
DTC P1105
Fuel pressure solenoid failure. Possible causes are:
connector or harness, or faulty fuel pressure solenoid.
DTC P1400
Manifold Differential Pressure (MDP) sensor circuit failure.
Possible causes are: connector or harness, or faulty MDP sensor.
DTC P1500
Generator FR terminal circuit failure. Possible causes are:
connector or harness.
DTC P1600
Serial communication link failure. Possible causes are:
connector or harness.
DTC P1715
Pulse Generator (PG) failure. Possible causes are: connector
or harness, or faulty PG.
DTC P1750
Solenoid failure. Possible causes are: connector or harness,
faulty converter clutch solenoid, shift control solenoid, or pressure
control solenoid.
DTC P0751
Automatic transaxle control relay failure. Possible causes
are: connector or harness, or automatic transaxle relay.
DTC P1791
Engine coolant temperature level input circuit (to TCM)
failure. Possible causes are: connector or harness.
DTC P1795
Throttle position input circuit failure. Possible causes are:
connector or harness.

PNP Switch ................................. Fig. 30 or 31
Starter Relay .................................... Fig. 32
TCM .............................................. Fig. 33
TP Sensor ........................................ Fig. 34
VAF Sensor ....................................... Fig. 35
VIC Valve Position Sensor ........................ Fig. 36
VSS .............................................. Fig. 37









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Fig. 1: ASD/Fuel Pump/MFI Relay Terminals (3000GT DOHC Turbo - Fuel
Pump)
Courtesy of Mitsubishi Motor Sales of America

Fig. 33: Identifying TCM Terminals
Courtesy of Mitsubishi Motor Sales of America
Fig. 34: Identifying TP Sensor Terminals
Courtesy of Mitsubishi Motor Sales of America
Fig. 35: Identifying VAF Sensor Terminals
Courtesy of Mitsubishi Motor Sales of America

wiring harness as necessary. If continuity exists, go to next step.
5) Reconnect PCM connector. Turn ignition switch to ON
position. Check voltage between chassis ground and MDP sensor
connector terminal No. 3. If voltage is not 4.8-5.2 volts, replace
PCM. If voltage is as specified, condition required to set DTC is not
present at this time. Go to next step.
6) Test is complete. Intermittent problem may exist. Road
test vehicle (if necessary) and attempt to duplicate conditions that
caused original complaint. Recheck for DTCs. If no DTCs are displayed,
go to INTERMITTENT DTCS .
DTC P1600: SERIAL COMMUNICATION LINK MALFUNCTION
DTC P1600 is related to automatic transmission diagnostics.
For diagnostic procedure, see TRANSMISSION SERVICE & REPAIR article.
DTC P1715: PULSE GENERATOR FAILURE
DTC P1715 is related to automatic transmission diagnostics.
For diagnostic procedure, see TRANSMISSION SERVICE & REPAIR article.
DTC P1750: SOLENOID FAILURE
DTC P1750 is related to automatic transmission diagnostics.
For diagnostic procedure, see TRANSMISSION SERVICE & REPAIR article.
DTC P1791: ENGINE COOLANT TEMPERATURE LEVEL INPUT TO TCM
DTC P1791 is related to automatic transmission diagnostics.
For diagnostic procedure, see TRANSMISSION SERVICE & REPAIR article.
SUMMARY
If no hard DTCs (or only pass DTCs) are present, driveability\
symptoms exist, or intermittent DTCs exist, proceed to H - TESTS W/O
CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START,
etc.) or intermittent diagnostic procedures.

Torque Converter Clutch Solenoid/Switch ......... Engine Performance
Traction Control Switch ........................... Anti-Lock Brakes
Trailer Tow Connector .............................. Exterior Lights
Trailer Tow Relay .................................. Exterior Lights
Transmission/Transaxle .......................... Engine Performance
Transmission Control Module (TCM) ............... Engine Performance\
Starters
Transmission Range Sensor ................................. Starters
Back-Up Lights
Engine Performance
Transmission Range Switch ........................... Back-Up Lights
Engine Performance
Anti-Theft System
Turn Signal Flasher ................................ Exterior Lights
Turn Signal Lights ................................. Exterior Lights
Twilight Sentinel Switch ......................... Headlight Systems
Daytime Running Lights
Vapor Canister Leak Detection Pump .............. Engine Performance
Vehicle Control Module (VCM) .................... Engine Performance\
Vehicle Dynamic Module ....................... Electronic Suspension
Vehicle Speed Control Servo ................. Cruise Control Systems
Vehicle Speed Sensor .......................... Data Link Connectors
Analog Instrument Panels
Cruise Control Systems
Electronic Suspension
Voltage Regulator .......................... Generators & Regulators
Water-In-Fuel Sensor ............................ Engine Performance
Analog Instrument Panels
Wheel Speed Sensors ............................... Anti-Lock Brakes
Window Timer Module .......................... Power Convertible Top
Windshield Intermittent Wiper Relay ........... Wiper/Washer Systems
Windshield Washer Motor ....................... Wiper/Washer Systems
Wiper Motor ................................... Wiper/Washer Systems









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