1998 MITSUBISHI MONTERO air condition

referred to as BARO pressure sensor. For terminal
identification, see VAF sensor under TERMINAL IDENTIFICATION.
For circuit and wire color identification, see
L - WIRING DIAGRAMS article.
1) Component testing procedure without using scan tool not
available from manufacturer at time of publication. Turn ignition
switch to ON position. Using scan tool, read BARO sensor pressure
(item 25). See BARO PRESSURE SENSOR SPECIFICATIONS table. If pressure
is not as specified, replace BARO pressure sensor. If pressure is as
specified, go to next step.
BARO PRESSURE SENSOR SPECIFICATIONS TABLE









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Altitude in Ft. (M) Pressure in kPa (mmHg)
0 (0) .......................................... 101 (768)
1969 (600) ...................................... 95 (710)
3937 (1200) ..................................... 88 (660)
5906 (1800) ..................................... 81 (610)









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2) Disconnect BARO pressure sensor connector. Using DVOM,
check for continuity between chassis ground and BARO pressure sensor
connector terminal No. 5. If continuity does not exist, repair wiring
harness as necessary. If continuity exists, go to next step.
3) Turn ignition switch to OFF position. With BARO pressure
sensor disconnected, disconnect PCM connector. Ground PCM connector
terminal No. 51. Using DVOM, check for continuity between chassis
ground and BARO pressure sensor connector terminal No. 2. If
continuity does not exist, repair wiring harness as necessary. If
continuity exists on Montero, go to next step. On 3000GT, go to step
5).
4) Ground PCM connector terminal No. 42. Check for continuity
between chassis ground and BARO pressure sensor connector terminal No.
1. If continuity does not exist, repair wiring harness as necessary.
If continuity exists, go to next step.
5) Reconnect PCM connector. With BARO pressure sensor
connector disconnected, turn ignition switch to ON position. Using
DVOM, check for voltage between chassis ground and BARO pressure
sensor connector terminal No. 1. 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 P0110: INTAKE AIR TEMPERATURE (IAT) SENSOR CIRCUIT
FAILURE
NOTE: IAT sensor is built into Volume Airflow (VAF) sensor. For
DTC P0110 test purposes, VAF sensor will be referred to as
IAT sensor. For terminal identification, see VAF sensor
under TERMINAL IDENTIFICATION . For circuit and wire color
identification, see L - WIRING DIAGRAMS article.
1) If using scan tool, go to step 3). Disconnect IAT sensor
connector. Using a thermometer, check engine compartment ambient
temperature. Using DVOM, check resistance between IAT sensor terminals
No. 5 and 6. Resistance should be 6000 ohms at 32
F (0C), 2700 ohms
at 68F (20C) or 400 ohms at 176F (80C). If resistance is not as
specified, replace IAT sensor. If resistance is as specified, go to

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 ECT sensor
connector terminal No. 1. If voltage is not 4.5-4.9 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 P0120: THROTTLE POSITION (TP) SENSOR 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). Disconnect TP sensor
connector. Using DVOM, check resistance between TP sensor terminals
No. 1 and No. 4. If resistance is not 3500-6500 ohms, replace TP
sensor. If resistance is as specified, go to next step.
2) Check resistance between TP sensor terminals No. 1 and 3
on Montero or No. 2 and 4 on 3000GT. While monitoring DVOM, slowly
open throttle from idle to fully open position. If resistance does not
change smoothly, replace TP sensor. If resistance changes smoothly, go
to step 4).
3) Turn ignition switch to ON position. Using scan tool, read
TP sensor voltage value (item 14). With throttle at idle, value should\
read 300-1000 mV. Value should increase while slowly opening throttle.
At wide open throttle, value should read 4500-5500 mV. If value is not
as specified, replace TP sensor. If value is as specified, go to next
step.
4) Disconnect TP sensor connector. Using DVOM, check
continuity between chassis ground and TP sensor connector terminal No.
1. If continuity does not exist, repair wiring harness as necessary.
If continuity exists on 3000GT, go to next step. On Montero, go to
step 6).
5) Check continuity between chassis ground and TP sensor
connector terminal No. 4. If continuity does not exist, repair wiring
harness as necessary. If continuity exists, go to next step.
6) Turn ignition switch to OFF position. Disconnect PCM
connector. Ground specified PCM connector terminal. See
TP SENSOR-TO-PCM WIRING HARNESS TERMINAL IDENTIFICATION table. Check
for continuity between chassis ground and specified TP sensor
connector terminal. If continuity does not exist, repair wiring
harness as necessary. If continuity exists on 3000GT, go to step 8).
On Montero, go to next step.
TP SENSOR-TO-PCM WIRING HARNESS TERMINAL IDENTIFICATION TABLE









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Application TP Sensor Terminal No. PCM Terminal No.
Montero ................. 3 ......................... 78
4 ......................... 42
3000GT .................. 2 ......................... 78









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7) Reconnect PCM connector. Turn ignition switch to ON
position. Check voltage between chassis ground and TP sensor connector
terminal No. 4 on Montero or No. 1 on 3000GT. 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

Front
Left ........................................................ 39
Right ....................................................... 11
Rear
Left ........................................................ 69
Right ....................................................... 59









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4) While monitoring scan tool, accelerate to 2500 RPM and
decelerate to 700 RPM (idle). Scan tool should switch from 0.6-1.0
volt to 0.4 volt or less. If voltage is not as specified, replace
HO2S. If voltage is as specified, go to next step.
5) On 3000GT, go to next step. On Montero, disconnect HO2S
connector and MFI relay connector. Using DVOM, check for continuity
between HO2S connector terminal No. 1 and MFI relay connector terminal
No. 1. If continuity does not exist, repair wiring harness as
necessary. If continuity exists, go to step 7).
6) Disconnect HO2S connector. Turn ignition switch to ON
position. Using DVOM, check voltage between chassis ground and HO2S
connector terminal No. 1. If battery voltage does not exists, repair
wiring harness as necessary. If battery voltage exists, go to next
step.
7) Turn ignition switch to OFF position. With HO2S connector
disconnected, disconnect PCM connector. Using DVOM, check for open or
short circuit between specified HO2S connector terminal and PCM
connector terminal. See
FRONT HO2S-TO-PCM HARNESS TERMINAL IDENTIFICATION table. If open or
short circuit exists, repair wiring harness as necessary. If open or
short circuit does not exist, go to next step.
FRONT HO2S-TO-PCM HARNESS TERMINAL IDENTIFICATION TABLE









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Application HO2S Terminal No. PCM Terminal No.
Montero - Federal .......... 3 ....................... 3
4 ...................... 71
All Others .............. ( 1) 3 ...................... 3
( 2) 3 ...................... 4
( 1) 4 ..................... 71
( 2) 4 ..................... 72
( 1) - Left front HO2S.
( 2) - Right front HO2S.









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8) Using DVOM, check for continuity between chassis ground
and HO2S connector terminal No. 2. If continuity does not exist,
repair wiring harness as necessary. If continuity exists, go to next
step.
9) Condition required to set DTC is not present at this time.
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 P0136, P0141, P0156 & P0161: REAR HEATED OXYGEN SENSOR
(HO2S) 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 next step. Disconnect rear HO2S

connector. Install Test Harness (MB998464) between HO2S and HO2S
connector. Using DVOM, check resistance between specified HO2S
connector terminals. See
REAR HO2S HEATER CONNECTOR TERMINAL IDENTIFICATION table. HO2S
resistance should be 12 ohms at 68
F (20C). If resistance is not as
specified, replace HO2S. If resistance is as specified, go to step 3).
REAR HO2S HEATER CONNECTOR TERMINAL IDENTIFICATION TABLE









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Application Terminals No.
Montero ............................................ 1 & 3
3000GT ............................................. 2 & 4









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2) Raise and support drive wheels. Start and warm engine to
operating temperature. Place A/T in Low (M/T in 2nd). Using scan tool,\
read HO2S voltage (item 59 for right side or 69 for left side). While
monitoring scan tool, accelerate to 3500 RPM. Scan tool should read 0.
6-1.0 volt. If voltage is not as specified, replace HO2S. If voltage
is as specified, go to next step.
3) On 3000GT, go to next step. On Montero disconnect HO2S
connector and MFI relay connector. Using DVOM, check for continuity
between HO2S connector terminal No. 1 and MFI relay connector terminal
No. 1. If continuity does not exist, repair wiring harness as
necessary. If continuity exists, go to next step.
4) Using DVOM, check for open or short circuit between
specified HO2S connector terminal and PCM connector terminal(s). See
REAR HO2S-TO-PCM WIRING HARNESS TERMINAL IDENTIFICATION table. If open
or short circuit exists, repair wiring harness as necessary. If open
or short circuit does not exist, go to next step.
REAR HO2S-TO-PCM WIRING HARNESS TERMINAL IDENTIFICATION TABLE









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Application HO2S Terminal No. PCM Terminal No.
Montero - Federal ........ 3 ........................ 26
4 ........................ 73
All Others ............ ( 1) 3 ....................... 26
( 2) 3 ....................... 27
( 1) 4 ....................... 73
( 2) 4 ....................... 74
( 1) - Left rear HO2S.
( 2) - Right rear HO2S.









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5) Using DVOM, check for continuity between chassis ground
and specified HO2S connector terminal. See
REAR HO2S CONNECTOR GROUND CIRCUIT IDENTIFICATION table. If continuity
does not exist, repair wiring harness as necessary. If continuity
exists, go to next step.
REAR HO2S CONNECTOR GROUND CIRCUIT IDENTIFICATION TABLE









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Application Terminal No.
Montero & 3000GT ....................................... 2









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6) Condition required to set DTC is not present at this time.
Test is complete. Intermittent problem may exist. Road test vehicle
(if necessary) and attempt to duplicate conditions that caused

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

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