1998 MITSUBISHI MONTERO Service Manual

original complaint. Recheck for DTCs. If no DTCs are displayed, go to
INTERMITTENT DTCS.
DTC P0170 & P0173: FUEL TRIM FAILURE
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
1) Specific self-diagnostic test not available from
manufacturer at time of publication. Check volume airflow sensor, fuel
injectors, engine coolant temperature sensor, intake air temperature
sensor, barometric or manifold absolute pressure sensor, heated oxygen
sensor. See appropriate DTC test. Check related connectors and
harnesses. See L - WIRING DIAGRAMS article.
2) Also check fuel pressure, check for intake air leaks, and
for cracked manifold. See F - BASIC TESTING article.
DTC P0201-P0206: FUEL INJECTOR CIRCUIT FAILURE
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
1) If using scan tool, go to step 3). Using a stethoscope or
long-bladed screwdriver, listen for clicking sound from each fuel
injector while engine is running or being cranked. If no sound is
heard from fuel injector(s), check fuel injector connections. Repair
connections as necessary. If connections are okay, go to next step.
2) Ensure engine coolant temperature is at 68
F (20C).
Disconnect fuel injector connector. Using DVOM, check resistance
between specified fuel injector terminals. See
FUEL INJECTOR TERMINAL IDENTIFICATION table. If resistance is not 2.0-
3.0 3000GT turbo or 13-16 ohms on all other models, replace fuel
injector(s). If resistance is as specified, go to step 6).
FUEL INJECTOR TERMINAL IDENTIFICATION TABLE









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Application Terminals No.
Montero ( 1) ........................................ 8 & 1
8 & 2
8 & 3
8 & 5
8 & 6
8 & 7
3000GT - Rear Bank ( 2)
Non-Turbo ........................................ 1 & 2
1 & 5
1 & 6
Turbo ............................................ 1 & 4
2 & 8
4 & 5
4 & 6
4 & 7
4 & 8
( 1) - Check resistance at intermediate fuel injector
connector (component side).
( 2) - Check resistance at rear fuel injector connector
(component side).









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3) Using scan tool, read FUEL INJECTOR DRIVE TIME (item 41)
while cranking engine. See INJECTOR CRANKING DRIVE TIME SPECIFICATIONS
table. Go to next step.
INJECTOR CRANKING DRIVE TIME SPECIFICATIONS TABLE









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Coolant Temperature Drive Time (ms)
32
F (0C)
Montero ...................................... 11.0-17.0
3000GT
DOHC
Non-Turbo ................................ 12.9-19.3
Turbo ..................................... 8.4-12.6
SOHC ....................................... 13.8-16.8
68
F (20C)
Montero ...................................... 28.0-42.0
3000GT
DOHC
Non-Turbo ................................ 36.1-54.1
Turbo .................................... 23.3-34.9
SOHC ....................................... 40.0-48.8
176
F (80C)
Montero ....................................... 7.4-11.2
3000GT
DOHC
Non-Turbo ................................. 8.2-12.4
Turbo ...................................... 5.4-8.2
SOHC ........................................ 8.6-10.6









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4) Ensure engine coolant temperature is at 176-205F (80-
95C), all accessories are off and A/T is in Park or M/T is in
Neutral. Using scan tool, read FUEL INJECTOR DRIVE TIME (item 41)
under specified engine conditions. See
INJECTOR OPERATING DRIVE TIME SPECIFICATIONS table. Go to next step.
INJECTOR OPERATING DRIVE TIME SPECIFICATIONS TABLE









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Engine Speed Drive Time (ms)
700 RPM
Montero ........................................ 2.1-3.3
3000GT
DOHC
Non-Turbo .................................. 2.5-3.7
Turbo ...................................... 1.7-2.9
SOHC ......................................... 2.3-3.5
2000-2500 RPM
Montero ........................................ 1.9-3.1
3000GT
DOHC
Non-Turbo .................................. 2.2-3.4
Turbo ...................................... 1.5-2.7
SOHC ......................................... 2.1-3.3
Suddenly Accelerated
Montero & 3000GT ................................... ( 1)
( 1) - Drive time should increase.









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5) Allow engine to idle after warm up. Using scan tool, shut
off fuel injectors in sequence. Idle should change when good fuel

injectors are shut off. If idle state does not change, check fuel
injector connection, spark plug and cable, and cylinder compression.
If conditions are not as specified in preceding steps, go to next
step.
6) On 3000GT, go to next step. On Montero, disconnect MFI
relay connector and fuel injector connector at faulty fuel injector.
Using DVOM, check for continuity between MFI relay connector terminal
No. 1 fuel injector intermediate connector terminal No. 8. If
continuity does not exist, repair wiring harness as necessary. If
continuity exists, go to step 9).
7) Disconnect fuel injector connector. Using DVOM, check
voltage between chassis ground and fuel injector connector terminal
No. 1. If battery voltage does not exist, repair wiring harness as
necessary. If battery voltage exists, go to next step.
8) Ground specified PCM connector terminal for appropriate
fuel injector. See INJECTOR-TO-PCM CIRCUIT IDENTIFICATION (3000GT)
table. Using DVOM, check for continuity between chassis ground and
terminal No. 2 of each fuel injector connector. If continuity does not
exist, repair appropriate circuit as necessary. If continuity exists,
condition required to set DTC is not present at this time. Go to step
10).
INJECTOR-TO-PCM CIRCUIT IDENTIFICATION (3000GT) TABLE









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Injector No. PCM Terminal No.
1 ...................................................... 1
2 ..................................................... 14
3 ...................................................... 2
4 ..................................................... 15
5 ...................................................... 3
6 ..................................................... 16









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9) Ground specified PCM connector terminal. See
INJECTOR-TO-PCM CIRCUIT IDENTIFICATION (MONTERO) table. Using DVOM,
check for continuity between chassis ground and specified fuel
injector connector terminal. If continuity does not exist, repair
appropriate circuit as necessary. If continuity exists, condition
required to set DTC is not present at this time. Go to next step.
INJECTOR-TO-PCM CIRCUIT IDENTIFICATION (MONTERO) TABLE









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Injector Injector Connector PCM
No. Terminal No. Terminal No.
1 ......................... 3 ........................ 1
2 ......................... 2 ....................... 14
3 ......................... 1 ........................ 2
4 ......................... 7 ....................... 15
5 ......................... 6 ........................ 3
6 ......................... 5 ....................... 16









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10) 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 P0300-P0306: CYLINDER MISFIRE DETECTED
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see

L - WIRING DIAGRAMS article.
1) Specific self-diagnostic test is not available from
manufacturer at time of publication. Check ignition coil, power
transistor, spark plugs, fuel injectors, heated oxygen sensor,
crankshaft position sensor, and related connectors and harnesses.
2) Also check compression pressure, timing belt, fuel
pressure, and for intake air leaks. See F - BASIC TESTING article.
DTC P0325: KNOCK SENSOR (KS) NO. 1 CIRCUIT FAILURE
NOTE: This test applies to 3000GT equipped with DOHC engine only.
For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
1) Component or scan tool testing procedure not available
from manufacturer at time of publication. Turn ignition switch to OFF
position. Disconnect KS connector and PCM connector. Ground PCM
connector terminal No. 91. Go to next step.
2) Using DVOM, check for continuity between chassis ground
and KS connector terminal No. 1. If continuity does not exist, repair
wiring harness as necessary. If continuity exists, go to next step.
3) Remove jumper wire from PCM connector terminal No. 1.
Check for continuity between chassis ground and KS connector terminal
No. 2. If continuity does not exist, repair wiring harness as
necessary. If continuity exists, go to next step.
4) 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 P0335: CRANKSHAFT POSITION (CKP) SENSOR CIRCUIT FAILURE
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
NOTE: Procedures are provided by manufacturer for component
testing using an engine analyzer with oscilloscope
capability. Refer to manufacturer's operation manual for
instructions in use of oscilloscope.
1) If using scan tool, go to step 3). Disconnect CKP sensor
connector. Install Test Harness (MB991348) between CKP sensor and
connector. Using engine analyzer with oscilloscope capability, connect
special patterns probe to CKP sensor connector terminal No. 2. Go to
next step.
2) Start engine. Compare oscilloscope wave pattern with
known-good wave pattern. See Fig. 38. Verify wavelength (time)
decreases as engine RPM increases. If wave pattern fluctuates to left
or right, check for loose timing belt or an abnormality in sensor
pick-up disc. If a rectangular wave pattern is generated even when
engine is not started, substitute known-good CKP sensor. Repeat test.
If wave pattern is still abnormal, go to step 6).
Fig. 38: Identifying Known-Good CKP Sensor Wave Pattern
Courtesy of Mitsubishi Motor Sales of America

3) Connect an engine tachometer. Crank engine. Ensure
ignition coil primary current toggles on and off. Using scan tool,
read engine cranking speed (item 22). Compare tachometer and scan tool\
RPM display. Go to next step.
4) If engine fails to start and tachometer reads zero RPM
when engine is cranked, check for broken timing belt or faulty CKP
sensor. If CKP sensor is suspected, substitute known-good CKP sensor.
Repeat test procedure. If engine fails to start, tachometer reads zero
RPM, and ignition coil primary current fails to toggle on and off,
check for faulty ignition coil, ignition circuit or power transistor.
If engine starts and readouts agree, go to next step.
5) Ensure A/C switch is in ON position to activate closed
throttle position switch. Allow engine to idle. Using scan tool, check
engine coolant temperature and read idle speed. See
IDLE RPM SPECIFICATIONS table. If RPM is not to specification, check
for faulty ECT sensor, basic idle speed adjustment, or idle air
control motor. If RPM is within specifications, go to next step.
IDLE RPM SPECIFICATIONS TABLE









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Engine Coolant Temperature Engine RPM
-4
F (-20C)
Montero ...................................... 1300-1500
3000GT
Non-Turbo .................................. 1275-1475
Turbo ...................................... 1300-1500
32
F (0C)
Montero ...................................... 1300-1500
3000GT
Non-Turbo .................................. 1225-1425
Turbo ...................................... 1300-1500
68
F (20C)
Montero ...................................... 1300-1500
3000GT
Non-Turbo .................................. 1100-1300
Turbo ...................................... 1300-1500
104
F (40C)
Montero ...................................... 1040-1240
3000GT
Non-Turbo ................................... 950-1150
Turbo ...................................... 1050-1250
176
F (80C)
Montero & 3000GT ............................... 600-800









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6) On 3000GT, go to next step. On Montero, disconnect CKP
sensor connector and MFI relay connector. Using DVOM, check for
continuity between CKP sensor connector terminal No. 3 and MFI relay
connector terminal No. 1. If continuity does not exist, repair wiring
harness as necessary. If continuity exists, go to next step.
7) With CKP sensor connector disconnected, check for
continuity between chassis ground and CKP sensor connector terminal
No. 1 on Montero or No. 2 on 3000GT. If continuity does not exist,
repair wiring harness as necessary. If continuity exists on 3000GT, go
to next step. On Montero, go to step 9).
8) Check for voltage between chassis ground and CKP sensor
connector terminal No. 3. If battery voltage does not exist, repair
wiring harness as necessary. If battery voltage exists, go to step
10).
9) Turn ignition switch to OFF position. With CKP sensor
connector disconnected, disconnect PCM connector. Check for continuity

between CKP sensor connector terminal No. 2 and PCM connector terminal
No. 43. If continuity does not exist, repair wiring harness as
necessary. If continuity exists, go to next step.
10) With ignition switch in ON position, check for voltage
between chassis ground and CKP sensor connector terminal No. 2. If 4.
8-5.2 volts do not exist, replace PCM. If voltage is to specification
and CKP sensor is suspected, go to next step.
11) 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 P0340: CAMSHAFT POSITION (CMP) SENSOR CIRCUIT FAILURE
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
NOTE: Procedures are provided by manufacturer for component
testing using an engine analyzer with oscilloscope
capability. Refer to manufacturer's operation manual for
instructions in use of oscilloscope.
1) If using scan tool, go to step 3). Disconnect CMP sensor
connector. Install Test Harness (MB991348) between CMP sensor and
connector. Using engine analyzer with oscilloscope capability, connect
special patterns probe to CMP sensor connector terminal No. 2. Go to
next step.
2) Start engine. Compare oscilloscope wave pattern with
known-good wave pattern. See Fig. 39. Verify wavelength (time)
decreases as engine RPM increases. If wave pattern fluctuates to left
or right, check for loose timing belt or an abnormality in sensor
pick-up disc. If a rectangular wave pattern is generated even when
engine is not started, substitute known-good CMP sensor. Repeat test.
If wave pattern is still abnormal, go to next step.
Fig. 39: Identifying Known-Good CMP Sensor Wave Pattern
Courtesy of Mitsubishi Motor Sales of America
3) On Montero, go to next step. On 3000GT, disconnect CMP
sensor connector. Turn ignition switch to ON position. Check voltage
between chassis ground and CMP sensor connector terminal No. 3. If
battery voltage does not exist, repair wiring harness as necessary. If
battery voltage exists, go to step 5).
4) Disconnect CMP sensor connector and MFI relay connector.
Using DVOM, check for continuity between CMP sensor connector terminal
No. 3 and MFI relay connector terminal No. 1. If continuity does not
exist, repair wiring harness as necessary. If continuity exists, go to
next step.
5) Check for continuity between chassis ground and CMP sensor
connector terminal No. 4 on 3000GT equipped with DOHC engine or 1 on

all other models. If continuity does not exist, repair wiring harness
as necessary. If continuity exists, on Montero, go to next step. On
3000GT, go to step 7).
6) Turn ignition switch to OFF position. With CMP sensor
connector disconnected, disconnect PCM connector. Check for continuity
between PCM connector terminal No. 50 and CMP sensor connector
terminal No. 2. If continuity does not exist, repair wiring harness as
necessary. If continuity exists, go to next step.
7) Turn ignition switch to ON position, check voltage between
chassis ground and CMP sensor connector terminal No. 2. 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.
8) 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 P0400 & P0403: EXHAUST GAS RECIRCULATION (EGR) VALVE
SYSTEM FAILURE
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
1) If using scan tool, go to step 8). Remove EGR valve.
Inspect valve for sticking or carbon deposits. Clean or replace EGR
valve as necessary. If EGR valve is okay, go to next step.
2) Connect a vacuum pump to EGR valve. Apply 19.7-19.8 in. Hg
of vacuum. If vacuum does not hold, replace EGR valve. If vacuum
holds, go to next step.
3) Apply 1.2-1.8 in. Hg to EGR valve. Blow air through one
side of EGR valve passage. If air blows through, replace EGR valve. If
air does not blow through, go to next step.
4) Apply 9.1 in. Hg to EGR valve. Blow air through one side
of EGR valve passage. If air does not blow through, replace EGR valve.
If air blows through, reinstall EGR valve and go to next step.
5) Mark and disconnect striped vacuum hoses and wiring
connector from EGR solenoid. Install vacuum pump to EGR solenoid
white-striped vacuum hose port on turbo, or Green-striped vacuum hose
port on all other models. Apply vacuum to EGR solenoid. Go to next
step.
6) Apply and remove 12 volts across EGR solenoid terminals.
Vacuum should hold with voltage applied. Vacuum should leak without
voltage applied. If EGR solenoid does not test as specified, replace
solenoid. If solenoid tests as specified, go to next step.
7) Using DVOM, check resistance across EGR solenoid
terminals. If resistance is not 36-44 ohms at 68
F (20C), replace
solenoid. If resistance is as specified, go to step 9).
8) Turn ignition switch to ON position. Using scan tool, turn
EGR solenoid on and off (item 10). Listen for clicking sound from EGR
solenoid. If no sound is heard, replace EGR solenoid. If sound is
heard, go to next step.
9) On 3000GT, go to next step. On Montero, disconnect EGR
solenoid connector and MFI relay connector. Using DVOM, check
continuity between EGR solenoid connector terminal No. 1 and MFI relay
connector terminal No. 3. If continuity does not exist, repair wiring
harness as necessary. If continuity exists, go to step 11).
10) Disconnect EGR solenoid connector. Using DVOM, check
voltage between chassis ground and EGR solenoid connector terminal No.
1. If battery voltage does not exist, repair wiring harness as
necessary. If battery voltage exists, go to next step.
11) Turn ignition switch to OFF position. Disconnect PCM
connector. Ground PCM connector terminal No. 6. Using DVOM, check for

continuity between chassis ground and EGR solenoid connector terminal
No. 2. If continuity does not exist, repair wiring harness as
necessary. If continuity exists, condition required to set DTC is not
present at this time. Go to next step.
12) 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 P0420, P0421 & P0431: CATALYST EFFICIENCY BELOW
THRESHOLD
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
Specific self-diagnostic test not available from manufacturer
at time of publication. Check catalytic converter and check for
cracked exhaust manifold. Also, see F - BASIC TESTING article.
DTC P0442: EVAPORATIVE (EVAP) EMISSION CONTROL SYSTEM LEAK
DETECTED
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
1) Remove fuel cap. Push fuel pipe restrictor to operate On-
board Fuel Vent Valve (OFLV). Install and tighten fuel cap. Remove
fuel cap and ensure distance between filler tube and OFLV is 1.1" (28
mm). If distance is as specified, go to next step. If distance is not
as specified, replace fuel tank filler tube assembly. Go to step 24).
2) Disconnect and plug air filter-to-EVAP vent solenoid hose
at air filter. Disconnect intake manifold plenum-to-EVAP purge
solenoid at intake manifold plenum. Install a "T" fitting between
vacuum hose and intake manifold plenum. Connect a hand-held
pressure/vacuum pump to "T" fitting. Go to next step.
CAUTION: DO NOT apply more than 0.57 psi in following step. Applying
more than specified psi can crack fuel tank.
NOTE: Ensure fuel tank is at least 1/4 full. The lower the fuel
level in fuel tank, the longer it takes to pressurize fuel
system.
3) Using scan tool, read Fuel Tank Differential Pressure
(FTDP) sensor (item 73). Using hand-held pressure/vacuum pump, apply\
0.42 psi. If scan tool reading reaches 0.42 psi, go to next step. If
reading does not reach 0.42 psi, go to step 9).
4) Wait 20 seconds and read scan tool. If scan tool reading
increases 0.06 psi or less, go to next step. If scan tool reading
increases more than 0.06 psi, go to step 21).
5) Disconnect EVAP canister purge hose. Connect Purge Flow
Indicator (MB995061) between EVAP canister and disconnected hose. Turn\
engine on and allow it to reach operating temperature. Turn all lights
and accessories off. Place transmission in Park or Neutral. Observe
purge flow indicator while increasing engine RPM several times. If
purge flow indicator reads less than 2.5 SCFH (20 cm(3)/sec), check
EVAP canister purge hose and EVAP canister port for clogging. If hose
and port are okay, check EVAP purge solenoid. See DTC P0443. If
solenoid is okay, replace EVAP canister. Go to step 24).
6) Using scan tool, read Engine Coolant Temperature (ECT)
sensor temperature (item 21). Compare scan tool reading with