1998 MITSUBISHI MONTERO check engine light

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

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 

(62-73 kPa) of vacuum applied to the brake booster.
PARKING/EMERGENCY BRAKE
NOTE: Adjust service brakes before adjusting parking brake.
Start engine, and apply brake pedal. Pull parking brake lever
with a force of 44-45 lbs. (196-200 N). Parking brake lever should
move up 3-5 notches on Diamante, Stealth and 3000GT, 4-6 notches on
Montero, and 5-7 notches on all other models. If adjustment is
necessary, turn adjusting nut located under console or at end of cable
rod. See Fig. 6.
Fig. 6: Adjusting Parking/Emergency Brake (Typical)
Courtesy of Mitsubishi Motor Sales of America.
REAR BRAKE SHOES
Fully release parking brake and depress brake pedal several
times to center shoes and adjust brake shoe clearance. Adjust shoes so
brake shoes lightly contact brake drum. Adjust parking brake, and
check pedal travel. Rotate brake drum to verify free movement.
STOPLIGHT SWITCH
Loosen lock nut, and adjust switch-to-pedal arm clearance to
0.02-0.04" (0.5-1.0 mm). Tighten lock nut. DO NOT depress master
cylinder push rod during stoplight switch adjustment.
TESTING

POWER BRAKE BOOSTER
System Check
1) Run engine for 1-2 minutes. Shut engine off, and depress
brake pedal several times with normal pressure. If pedal height
gradually becomes higher with successive applications, power brake
booster is okay. If pedal height remains steady, power brake booster
is not operating properly, go to next step.
2) With engine stopped, depress brake pedal repeatedly until
pedal height no longer falls. Hold brake pedal down, and start engine.
If pedal moves downward slightly, power brake booster is okay. If
pedal height does not change, power brake booster is not operating
properly, go to next step.
3) With engine running, press and hold brake pedal. Shut off
engine. Hold brake pedal for 30 seconds. Brake pedal height should not
change. If pedal rises, power brake booster is not operating properly,
go to next step.
4) If brake booster operation is not as specified in each
step, disconnect vacuum hose at brake booster and check for sufficient
vacuum with engine running. Also check brake booster check valve
operation. Repair or replace as necessary.
Check Valve Inspection
Remove vacuum hose from power brake booster. Do not remove
check valve from hose. Check valve should hold vacuum in one direction
and allow air to pass in other direction.
LOAD-SENSING PROPORTIONING VALVE (LSPV)
Montero
1) Before diagnosing Load-Sensing Proportioning Valve (LSPV)\
,
ensure all other brake components are operating properly. When all
other brake system components are determined to be okay, ensure LSPV
spring length is within specification. See Fig. 1. See LOAD-SENSING
PROPORTIONING VALVE (LSPV) under ADJUSTMENTS.
2) After spring length is determined to be within
specification, connect pressure gauges to input and output ports of
LSPV. See Fig. 7. Bleed brake system. See BLEEDING BRAKE SYSTEM.
Fig. 7: Connecting Pressure Gauges To LSPV (Montero)
Courtesy of Mitsubishi Motor Sales of America.
3) With vehicle unloaded at correct ride height and LSPV
spring correctly adjusted to 8.9" (227 mm), slowly depress brake pedal\

specified, bleed system and inspect hydraulic and clutch components.
See CLUTCH PEDAL SPECIFICATIONS table.
CLUTCH PEDAL INTERLOCK SWITCH
1) Place transmission in Neutral and apply parking brake.
Turn ignition switch to START position with clutch pedal not
depressed. Engine should not crank. If engine cranks, adjust or
replace interlock switch.
2) Disconnect interlock switch connector. Interlock switch
connector is located at clutch pedal. Depress and release interlock
switch. Using ohmmeter, check continuity between interlock switch
terminals. If continuity exists with interlock switch depressed and
does not exist with switch released, switch is okay. Adjust or replace
as necessary.
REMOVAL & INSTALLATION
CLUTCH ASSEMBLY
Removal (2WD Models)
1) Disconnect negative battery cable. Remove shift knob, dust
cover retaining plate, gaskets, stopper plate and control lever
assembly. Raise and support vehicle.
2) Remove front exhaust pipe. Drain transmission fluid. Index
mark drive shaft flange and remove drive shaft.
3) Disconnect back-up light switch connector, speedometer
cable connection and exhaust pipe mounting bracket. Remove lower
bellhousing cover. Disconnect clutch cable from clutch lever.
4) Support transmission with jack. Remove rear engine mount
nuts and bolts from transmission. Remove crossmember with rear engine
mount. Remove remaining bellhousing bolts, move transmission toward
rear and lower from vehicle.
5) If reusing pressure plate, index mark pressure plate to
flywheel for installation reference. Install a clutch alignment tool
to prevent pressure plate and clutch disc from dropping. Loosen
pressure plate bolts gradually in a crisscross pattern to avoid
warping pressure plate flange during removal. Remove pressure plate
and clutch disc. See Fig. 3.
Inspection
1) Check release bearing and release fork for damage or wear.
DO NOT clean release bearing assembly in solvent.
2) Inspect pressure plate surface for wear, cracks, and/or
discoloration. Measure diaphragm spring ends for wear and uneven
height. Replace assembly if height difference between fingers exceeds
.02" (.5 mm).
3) Check facing of clutch disc for loose rivets, uneven
contact, deterioration, seizure or oil saturation. Measure distance
from clutch disc surface to head of rivet. Replace clutch disc if
distance is less than .012" (.30 mm). Replace worn or defective
components as necessary. See Fig. 4.
CAUTION: Install clutch disc with manufacturer's stamp mark (located
near hub of clutch disc) toward pressure plate.
Installation
1) Using a clutch alignment tool, install pressure plate and
clutch disc. If reusing pressure plate, ensure index marks are
aligned. Tighten bolts evenly in a crisscross pattern to
specification. See TORQUE SPECIFICATIONS . See Fig. 3.
2) Clean release bearing sliding surface. DO NOT clean

release bearing with solvent. Apply a light coat of multipurpose
grease to release bearing sliding surface. Apply a very light coating
of grease to input shaft splines. DO NOT allow grease or dirt on
clutch disc or pressure plate surfaces.
3) To install remaining components, reverse removal
procedure. Refill all fluids to proper levels. Adjust all control
cables, clutch pedal height and free play. See CLUTCH PEDAL HEIGHT and
CLUTCH PEDAL FREE PLAY under ADJUSTMENTS. See Fig. 1.
Removal (4WD Models)
1) Remove switch panel from rear console. Remove suspension
control switch or hole cover. Disconnect rear console harness
connector. Remove side panel. Remove rear console assembly. Remove
shift lever knob(s). Remove floor console harness connector. Remove
front console assembly.
2) Move transmission lever to Neutral position and transfer
lever to 4H (4WD high range) position. Remove control lever boot
retainer and boot. Remove transmission and transfer control lever
assemblies. Remove control lever bushing (transmission), gaskets and
stopper plates.
3) Raise and support vehicle. Remove skid plate and front
exhaust pipe. Drain transmission and transfer case fluid. Index mark
front and rear drive shaft flanges. Remove front and rear drive
shafts.
4) Remove drive shaft dust seals. Disconnect HI/LO and
2WD/4WD detection switch connectors. Disconnect back-up light switch
connector. Disconnect center differential lock detection switch
connector. Disconnect center differential lock operation switch
connector. Disconnect 4WD operation detection switch.
5) Disconnect speedometer cable. Remove clutch slave cylinder
heat shield. Remove clutch slave cylinder (without disconnecting
hydraulic line) and wire aside. Remove starter and starter cover.
Remove heat shield, both transmission stays and bellhousing lower
cover.
6) Support transmission with transmission jack. Remove
transfer case roll stopper and bracket. Remove crossmember and engine
mounting rear insulator. Remove transfer case protector bracket and
mass damper. Remove remaining bellhousing bolts. Pull toward rear of
vehicle to free transmission input shaft from clutch. Lower
transmission/transfer assembly from vehicle.
7) If reusing pressure plate, mark pressure plate to flywheel
for installation reference. Insert a clutch alignment tool to prevent
pressure plate and clutch disc from dropping. Loosen pressure plate
bolts gradually in a crisscross pattern to avoid warping pressure
plate flange during removal. Remove pressure plate and clutch disc.
See Fig. 3 .
Fig. 3: Removing & Installing Clutch On Flywheel (Typical)
Courtesy of Mitsubishi Motor Sales of America.
Inspection
1) Check release bearing and release fork for damage or wear.

coolant is 176-203F (80-95C). Turn engine off. Insert a paper clip
in engine speed detection connector. See Fig. 3. Connect a tachometer
to paper clip.
Fig. 3: Locating Engine Speed Detection Connector (3000GT - DOHC)
Courtesy of Mitsubishi Motor Sales of America
3) Install a timing light. Start engine and allow it to idle.
Using tachometer, read curb idle (RPM). Multiply RPM reading by 3 to
obtain actual curb idle speed. Ensure curb idle speed is 600-700 RPM.
Turn engine off. Curb idle speed is automatically controlled by Idle
Air Control (IAC) system. If curb idle speed is not as specified, see
DTC P0505 in G - TESTS W/CODES article.
4) Disconnect waterproof female connector from Brown ignition
timing check connector. See Fig. 4. Using a jumper wire, ground
ignition timing check terminal to read basic ignition timing. Using
timing light, read basic ignition timing value. See
IGNITION TIMING SPECIFICATIONS table. If basic ignition timing is
within specification, go to next step. If basic ignition timing is not
within specification, see DTC P0335 in G - TESTS W/CODES article.
5) Remove jumper wire to read actual ignition timing. Using
timing light, read actual ignition timing value. If actual ignition
timing is not within specification, see DTC P0335 in G - TESTS W/CODES
article.

Fig. 4: Locating Ignition Timing Check Connector
Courtesy of Mitsubishi Motor Sales of America
3000GT (SOHC)
1) Ignition timing is controlled by Powertrain Control Module
(PCM) and is not adjustable. Manufacturer provides procedure for
checking timing.
2) Start engine and warm engine until engine temperature
coolant is 176-203
F (80-95C). Turn engine off. Insert a paper clip
in noise filter connector. See Fig. 5. Connect a tachometer to paper
clip.
Fig. 5: Locating Noise Filter Connector
Courtesy of Mitsubishi Motor Sales of America
3) Install a timing light. Start engine and allow it to idle.
Using tachometer, read curb idle speed (RPM). Ensure curb idle speed