1998 MITSUBISHI MONTERO coolant temperature

TROUBLE CODE DEFINITION
When DTC is obtained, refer to appropriate DTC test
procedure.
DIAGNOSTIC TROUBLE CODES (DTCS)
NOTE: DTCs can only be retrieved by using a scan tool. Listed DTCs
are retrieved using a generic scan tool. MUT II scan tool
can be used, but it may not read all DTCs. DTCS listed are
not used on all vehicles.
DTC P0100
Volume Airflow (VAF) circuit failure. Possible causes are:
connector or harness, or faulty VAF sensor.
DTC P0105
Barometric (BARO) pressure circuit failure. Possible causes
are: connector or harness, or faulty BARO pressure sensor.
DTC P0105
Manifold Absolute Pressure (MAP) circuit failure. Possible
causes are: connector or harness, or faulty MAP sensor.
DTC P0110
Intake Air Temperature (IAT) circuit failure. Possible causes\
are: connector or harness, or faulty VAF sensor.
DTC P0115
Engine Coolant Temperature (ECT) circuit failure. Possible
causes are: connector or harness, or faulty ECT sensor.
DTC P0120
Throttle Position (TP) circuit failure. Possible causes are:
connector or harness, or faulty TP sensor.
DTC P0125
Excessive time to enter closed loop fuel control. Possible
causes are: faulty front HO2S, HO2S connector or harness, or faulty
fuel injector.
DTC P0130
Front Heated Oxygen Sensor (HO2S) circuit failure. Possible
causes are: connector or harness, or faulty HO2S.
DTC P0135
Front Heated Oxygen Sensor (HO2S) heater circuit failure.
Possible causes are: connector or harness, or faulty HO2S.
DTC P0136
Rear Heated Oxygen Sensor (HO2S) circuit failure. Possible
causes are: connector or harness, or faulty HO2S.
DTC P0141
Rear Heated Oxygen Sensor (HO2S) heater circuit failure.
Possible causes are: connector or harness, or faulty HO2S.
DTC P0150
Heated Oxygen Sensor (HO2S) circuit failure (bank 2, sensor
1). Possible causes are: connector or harness, or HO2S.

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.

next step.
2) Using a hair dryer, warm IAT sensor while monitoring DVOM.
Resistance should decrease evenly as temperature rises. If resistance
remains unchanged, replace IAT sensor. If resistance changes, go to
step 4).
3) Turn ignition switch to ON or RUN position. Using a
thermometer, check engine compartment ambient temperature. Using scan
tool, read IAT sensor temperature (item 13). Compare both readings. If\
readings are not about the same, replace IAT sensor. If readings are
about the same, turn ignition off and go to next step.
4) Disconnect IAT sensor connector. Using DVOM, check for
continuity between chassis ground and IAT sensor connector terminal
No. 5. If continuity does not exist, repair wiring harness as
necessary. If continuity exists, go to next step.
5) On 3000GT, go to next step. On Montero, turn ignition
switch to OFF position. With IAT sensor connector disconnected,
disconnect PCM connector. Ground PCM connector terminal No. 62. Check
for continuity between IAT sensor connector terminal No. 6 and chassis
ground. If continuity does not exist, repair wiring harness as
necessary. If continuity exists, go to next step.
6) Reconnect PCM connector. Turn ignition switch to ON
position. Check voltage between IAT sensor connector terminal No. 6
and chassis ground. If voltage is not 4.5-4.9 volts, replace PCM. If
voltage is as specified, replace IAT sensor.
DTC P0115: ENGINE COOLANT TEMPERATURE (ECT) SENSOR 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 2). Disconnect ECT sensor
connector. Remove ECT sensor from intake manifold. Submerge
temperature sensing portion of ECT sensor in hot water. Using DVOM,
check resistance across ECT sensor terminals. See
ECT SENSOR RESISTANCE SPECIFICATIONS table. If resistance is not as
specified, replace ECT sensor. If resistance is as specified, go to
step 3).
ECT SENSOR RESISTANCE SPECIFICATIONS TABLE









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Water Temperature Approximate Resistance in Ohms
32
F (0C) .......................................... 5800
68F (20C) ......................................... 2400
104F (40C) ........................................ 1100
176F (80C) ......................................... 300








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2) Turn ignition switch to ON or RUN position. Using a
thermometer, check engine compartment ambient temperature. Using scan
tool, read ECT SENSOR TEMPERATURE (item 21). Compare both readings. If\
readings are not about the same, replace ECT sensor. If readings are
about the same go to next step.
3) Disconnect ECT sensor connector. Using DVOM, check
continuity between chassis ground and ECT sensor connector terminal
No. 2. If continuity does not exist, repair wiring harness as
necessary. If continuity exists on 3000GT, go to step 5). On Montero,
go to next step.
4) Turn ignition switch to OFF position. With ECT sensor
connector disconnected, disconnect PCM connector. Ground PCM connector
terminal No. 44. Check continuity between chassis ground and ECT
sensor connector terminal No. 1. If continuity does not exist, repair

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

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

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

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 8).
4) 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 20).
5) Using scan tool, read Engine Coolant Temperature (ECT)
sensor temperature (item 21). Compare scan tool reading with
temperature gauge reading. If readings are about the same, go to next
step. If readings are not about the same, go to DTC P0115 test.
6) Using a thermometer, check engine compartment ambient
temperature. Using scan tool, read Intake Air Temperature (IAT) sensor\
temperature (item 13). Compare IAT sensor and thermometer readings. If\
readings are not about the same, go to DTC P0110 test. If readings are
about the same, go to next step.
7) Using scan tool, read Power Steering Pressure (PSP) switc\
h
status (item 27). Switch status should read ON when steering wheel is
turned. If switch status is as specified, go to step 20). If switch
status is not as specified, go to DTC P0551 test.
8) Remove fuel cap. Install a fuel tank filler tube adapter
in place of fuel cap. Plug fuel filler tube adapter hose. 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 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.
9) 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, replace fuel cap. Go
to step 20). If reading does not reach 0.42 psi, go to next step.
10) Disconnect hand-held pressure/vacuum pump from "T"
fitting. Install an evaporative emission system tester in place of
vacuum held pump and apply 0.49 psi. Wait two minutes. If pressure
drops less than 0.20 psi, go to next step. If pressure drops 0.29 psi
or more, go to step 13).
11) Disconnect EVAP purge solenoid-to-EVAP canister hose at
EVAP canister. Connect hand-held pressure/vacuum pump to hose and
apply 0.9 psi. If pressure is not maintained, check EVAP purge
solenoid for leak. If EVAP purge solenoid is okay, replace hose. Go to
step 24). If pressure is maintained, go to next step.
12) Disconnect EVAP vent solenoid-to-EVAP canister hose at
EVAP canister. Connect hand-held pressure/vacuum pump to hose and
apply 0.9 psi. If pressure is not maintained, check EVAP vent solenoid
for leak. If EVAP vent solenoid is okay, replace hose. Go to step 20).
If pressure is maintained, replace EVAP canister. Go to step 24).
13) Ensure hoses are properly routed and connected. See M -