sensor MITSUBISHI MONTERO 1998 Service Manual

VACUUM DIAGRAMS article. Install hoses as necessary and go to step
20). If hoses are okay, go to next step.
14) Disconnect OFLV-to-EVAP canister hose at OFLV and EVAP
canister. Plug hose at OFLV end. Connect hand-held pressure/vacuum
pump to hose at EVAP canister end. Apply 0.9 psi. If pressure is not
maintained, replace hose. Go to step 20). If pressure is maintained,
go to next step.
15) Using scan tool, read Fuel Tank Differential Pressure
(FTDP) sensor (item 73). Connect hand-held pressure/vacuum pump to
OFLV. While monitoring scan tool, 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 19).
16) Disconnect OFLV-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, go to next step. If pressure is
maintained, go to step 18).
17) Disconnect EVAP purge solenoid-to-EVAP canister hose at
EVAP canister. Connect hand-held pressure/vacuum pump to hose.
Disconnect intake manifold plenum-to-EVAP purge solenoid at intake
manifold plenum. Operate vacuum pump several times to apply vacuum. If
vacuum leaks, replace EVAP canister. Go to step 20). If vacuum does
not leak, repair clog in hose between EVAP canister and EVAP Purge
solenoid. Go to step 20).
18) Disconnect EVAP canister-to-OFLV hose at OFLV. If vacuum
does not leak, repair clog in hose between EVAP canister and OFLV. Go
to step 20). If vacuum leaks, check fuel tank filler tube assembly. If
fuel tank filler tube assembly is okay, repair clog in hose between
OFLV and fuel cut-off valve. Go to step 20).
19) Replace fuel tank filler tube and OFLV-to-fuel cut-off
valve hose. While monitoring scan tool, apply 0.42 psi with hand-held
pressure/vacuum pump. If scan tool reading does not reach 0.42 psi,
replace fuel tank. Go to next step.
20) Road test vehicle and attempt to duplicate conditions
that caused original complaint. Recheck for DTCs. If no DTCs are
displayed, test is complete.
DTC P0500: VEHICLE SPEED SENSOR (VSS) CIRCUIT FAILURE
NOTE: Speedometer testing procedures for 3000GT are not available
from manufacturer at time of publication. 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 4). On 3000GT, go to step
3). On Montero, speedometer testing procedures using DVOM require
removal of instrument panel. Removal and installation of instrument
panel is basically an unbolt and bolt-on procedure.
2) DO NOT disconnect connectors. Using DVOM, check continuity
between indicated speedometer terminals. See Fig. 40. Ensure
continuity pulses on and off with speedometer shaft revolution. If
continuity is not as specified, replace speedometer. If continuity is
as specified, go to next step.

specified VSS connector terminal. See
VSS VOLTAGE FEED CIRCUIT IDENTIFICATION table. 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.
VSS VOLTAGE FEED CIRCUIT IDENTIFICATION TABLE









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Application Terminal No.
Montero ................................................ 1
3000GT ................................................. 3









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9) 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 P0505: IDLE CONTROL SYSTEM FAILURE
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
1) 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. If using engine analyzer, go to step 3). If using scan
tool, go to next step.
2) Using scan tool, read Idle Air Control (IAC) position
sensor step (item 45). See IAC POSITION SENSOR STEP SPECIFICATIONS
table. If scan tool does not read as specified, replace IAC position
sensor. If readings are as specified, go to step 5).
IAC POSITION SENSOR STEP SPECIFICATIONS TABLE









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A/C Switch Position Standard Step Value
Off ................................................. 2-25
Off To On ............................ Increase From 10-70
( 1) ................................... Increase From 5-50
( 1) - Brakes applied. A/C Off on Montero. A/C On on 3000GT.
Move gear selector lever to Drive position.









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NOTE: Check wave pattern when idle speed increases when A/C is
turned on. Wave pattern display lasts less than one second.
3) Disconnect IAC motor connector. Install Test Harness
(MB998463) between IAC motor and connector. Using engine analyzer with\
oscilloscope capability, connect special patterns probe in sequence to
test harness terminals No. 1 (Red clip), 3 (Blue clip), 4 (Black cl\
ip)
and 6 (Yellow clip) or PCM terminals No. 4, 5, 17 and 18 respectively.\
Start engine and allow it to idle. Turn A/C on. Compare oscilloscope
wave pattern with known-good wave pattern. See Fig. 44. Turn engine
off. If wave pattern is not normal, go to next step. If wave pattern
is normal, fault is intermittent. See INTERMITTENT DTCS.

9) 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 .
10) Road test vehicle and attempt to duplicate conditions
that caused original complaint. Recheck for DTCs. If no DTCs are
displayed, test is complete.
DTC P0510: CLOSED THROTTLE POSITION (TP) SWITCH FAILURE
NOTE: Closed TP switch is built into TP sensor. For DTC P0510
test purposes, TP sensor will be referred to as closed
TP switch. For terminal identification, see TP 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 closed TP
switch connector. Check for continuity between closed TP switch
connector terminals No. 1 and 2 on Montero or No. 3 and 4 on 3000GT.
Go to next step.
2) Depress accelerator pedal. Continuity should not exist.
Release accelerator pedal. Continuity should exist. If continuity is
not as specified, replace TP sensor. If continuity is as specified, go
to step 4).
3) Using scan tool, read closed TP switch state (item 26).
With accelerator pedal released, scan tool should read ON. With
accelerator pedal slightly depressed, scan tool should read OFF. If
closed TP switch does not test as specified, replace TP sensor. If
closed TP switch tests as specified, disconnect closed TP switch
connector and go to next step.
4) On 3000GT, go to next step. On Montero, turn ignition
switch to OFF position. Disconnect PCM connector. Ground PCM connector
terminal No. 79. Using DVOM, check continuity between chassis ground
and closed TP switch connector terminal No. 2. If continuity does not
exist, repair wiring harness as necessary. If continuity exists, go to
next step.
5) Check continuity between chassis ground and closed TP
switch connector terminal No. 1 on Montero or No. 4 on 3000GT. If
continuity does not exist, repair wiring harness as necessary. If
continuity exists, go to next step.
6) Turn ignition switch to ON position. Check voltage between
chassis ground and closed TP switch connector terminal No. 2 on
Montero or No. 3 on 3000GT. If voltage is less than 4 volts, replace
PCM. If voltage is more than 4 volts, condition required to set DTC is
not present at this time. Go to next step.
7) 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 P0551: POWER STEERING PRESSURE (PSP) SENSOR CIRCUIT
PERFORMANCE
NOTE: For terminal identification, see TERMINAL IDENTIFICATION. For
circuit and wire color identification, see
L - WIRING DIAGRAMS article.
1) Using scan tool, read Power Steering Pressure (PSP) statu\
s
(item 27). Switch status should read ON when steering wheel is turned.\
If switch status is as specified, fault is intermittent. See
INTERMITTENT DTCS . If switch status is not as specified, go to next
step.

2) Disconnect pressure hose from oil pump. See Fig. 45.
Install Adapter (MB990993) on oil pump. Install Adapter (MB990994) o\
n
disconnected hose. Connect Pressure Gauge (MB990662) and shutoff valve\
between adapters. Open shutoff valve. Bleed steering hydraulic system.
See HYDRAULIC SYSTEM BLEEDING in STEERING SYSTEM article.
Fig. 45: Testing PSP Sensor Circuit
Courtesy of Mitsubishi Motor Sales of America
3) Install a thermometer in fluid reservoir. Start engine and
allow it to idle. Turn steering wheel several times until fluid
temperature reaches 122-140
F (50-60C). Disconnect PSP switch
connector. Install a DVOM between ground and PSP switch terminal. See
Fig. 45 . Note continuity reading on DVOM. Go to next step.
4) With engine idling, gradually close shutoff valve to
increase power steering system pressure. Check pressure when PSP
switch is actuated by watching for a change in continuity. PSP switch

should be actuated when pressure is 218-290 psi. Gradually open
shutoff valve to decrease pressure. Check pressure when PSP switch is
de-actuated. PSP switch should de-actuate at 102-174 psi. Turn engine
off. If PSP operates as specified, go to next step. If PSP does not
operate as specified, replace PSP switch. Go to step 8).
5) Disconnect PSP switch connector. On 3000GT, go to next
step. On Montero, turn ignition off. Disconnect PCM connector. Ground
PCM connector terminal No. 54. Using DVOM, check continuity between
chassis ground and PSP switch connector terminal No. 1. If continuity
does not exist, repair wiring harness as necessary. If continuity
exists, go to next step.
6) Turn ignition on. Using DVOM, check voltage between ground
and PSP switch connector terminal No. 1. If battery voltage does not
exist, replace PCM. If battery voltage exists, go to next step.
7) Road test vehicle and attempt to duplicate conditions that
caused original complaint. Recheck for DTCs. If no DTCs are displayed,
test is complete.
DTC P0705: TRANSMISSION RANGE SENSOR CIRCUIT FAILURE
DTC P0705 is related to automatic transmission diagnostics.
For diagnostic procedure, see TRANSMISSION SERVICE & REPAIR article.
DTC P1103 & P1104: TURBOCHARGER WASTEGATE SOLENOID CIRCUIT
FAILURE
NOTE: This test applies to 3000GT with turbocharger only. 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 7). Remove vacuum hoses
from turbocharger wastegate solenoid. Disconnect solenoid harness
connector. Connect a vacuum pump to solenoid nipple "A". See Fig. 46.
Go to next step.
2) Using jumper wires, connect battery voltage and ground to
solenoid terminals. Ensure vacuum does not hold with nipple "B"
unplugged, and negative jumper wire connected. If solenoid does not
test as specified, replace solenoid. If solenoid tests as specified,
go to next step.
Fig. 46: Testing Turbocharger Wastegate Solenoid
Courtesy of Mitsubishi Motor Sales of America
3) Ensure solenoid holds vacuum with nipple "B" plugged, and
negative jumper wire connected. If solenoid does not test as

specified, replace solenoid. If solenoid tests as specified, go to
next step.
4) Ensure solenoid holds vacuum with nipple "B" unplugged,
and negative jumper wire connected. If solenoid does not test as
specified, replace solenoid. If solenoid tests as specified, go to
next step.
5) Check resistance between solenoid terminals. If resistance
is not 36-44 ohms at 68
F (20C), replace solenoid. If resistance is
as specified, go to step 7).
6) Turn ignition switch to ON position. Using scan tool, turn
fuel pressure solenoid on and off (item 09). Clicking sound should be
heard. If clicking sound is heard, go to step 9). If clicking sound is
not heard, go to next step.
7) Disconnect fuel pressure solenoid connector. Using DVOM,
check for voltage between chassis ground and fuel pressure solenoid
terminal No. 1. If battery voltage does not exist, repair wiring
harness as necessary. If battery voltage exists, go to next step.
8) Turn ignition switch to OFF position. Disconnect PCM
connector. Ground PCM connector terminal No. 48. Check continuity
between chassis ground and fuel pressure solenoid connector terminal
No. 2. If continuity does not exist, repair wiring harness as
necessary. If continuity exists, go to next step.
9) 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 P1400: MANIFOLD DIFFERENTIAL PRESSURE (MDP) SENSOR
CIRCUIT FAILURE
NOTE: For terminal identification, see 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. Warm vehicle to
normal operating temperature and allow engine to idle. Go to next
step.
2) Using scan tool, read intake manifold pressure (item 95).\
See INTAKE MANIFOLD PRESSURE SPECIFICATIONS table. If scan tool does
not read as specified, replace MDP sensor. If scan tool reads as
specified, go to next step.
INTAKE MANIFOLD PRESSURE SPECIFICATIONS TABLE









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Application psi (kPa)
Montero .............................. 3.0-4.9 (20.6-34.0)
3000GT
DOHC
Non-Turbo ........................ 3.7-5.7 (25.5-38.9)
Turbo ............................ 4.2-6.2 (29.0-42.4)
SOHC ............................... 3.9-5.8 (26.5-39.9)









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3) Disconnect MDP sensor connector. Using DVOM, check
continuity between chassis ground and MDP sensor connector terminal
No. 2. If continuity does not exist, repair wiring harness as
necessary. If continuity exists, go to next step.
4) Turn ignition switch to OFF position. With MDP sensor
connector disconnected, disconnect PCM connector. Ground PCM connector
terminal No. 92. Check continuity between chassis ground and MDP
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. 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.

H - TESTS W/O CODES
1998 Mitsubishi Montero
1998 ENGINE PERFORMANCE
Mitsubishi - Trouble Shooting - No Codes
Diamante, Eclipse, Galant, Mirage, Montero, Montero Sport,
3000GT
INTRODUCTION
Before using this article to diagnose symptoms or
intermittent faults, perform testing in F - BASIC TESTING article and
G - TESTS W/CODES article. Use this article to diagnose driveability
problems existing when a hard Diagnostic Trouble Code (DTC) is not
present.
NOTE: Some driveability problems may have been corrected by
manufacturer with a revised Powertrain Control Module (PCM).
Check with manufacturer for latest PCM.
Symptom checks can direct technician to malfunctioning
component(s) for further diagnosis. A symptom should lead to a
specific component, system test or adjustment.
Use intermittent test procedures to locate driveability
problems that DO NOT occur when vehicle is being tested. These test
procedures should also be used if an intermittent DTC was present, but
no problem was found during self-diagnostic testing.
NOTE: For specific testing procedures, see G - TESTS W/CODES
article. For specifications, see D - ADJUSTMENTS or
C - SPECIFICATIONS article.
SYMPTOMS
SYMPTOM DIAGNOSIS
Symptom checks cannot be used unless problem occurs while
vehicle is being tested. Before using this article to diagnose any
symptom, perform basic diagnostic procedures in F - BASIC TESTING
article and self-diagnostics in G - TESTS W/CODES article in order to
reduce diagnostic time. The following symptoms are available for
diagnosis:
* Difficult To Start/No Start (Cranks Okay)
* Rough Or Unstable Idle
* Engine Hesitates Or Poor Acceleration
* Engine Surges
* Detonation Or Knocking
* Poor Fuel Mileage
DIFFICULT TO START/NO START (CRANKS OKAY)
* Check idle air control (DC) motor (if applicable).
* Check idle air control (stepper) motor (if applicable).
* Check ignition switch.
* Check camshaft position sensor.
* Check crankshaft position sensor.
* Check park/neutral position switch (A/T).
* Check volume airflow sensor.
* Check engine coolant temperature sensor.

* Check power supply to PCM.
* Check fuel pressure.
* Check ignition timing.
* Check for disconnected or damaged vacuum hoses.
* Check for control relay malfunction.
* Check for SFI system malfunction.
* Check for fuel pump drive control system malfunction.
* Check for ignition coil malfunction.
* Check for power transistor malfunction (if applicable).
* Check for fuel injector malfunction.
* Check for PCM malfunction.
* Ensure electrical harness, connectors and wires are not
broken, bent or loose.
ROUGH OR UNSTABLE IDLE
* Check intake air temperature sensor.
* Check EVAP purge control solenoid valve (if applicable).
* Check vehicle speed sensor.
* Check engine coolant temperature sensor.
* Check barometric pressure sensor (if applicable).
* Check manifold absolute pressure sensor (if applicable).
* Check ignition switch.
* Check throttle position sensor.
* Check camshaft position sensor.
* Check crankshaft position sensor.
* Check power steering oil pressure switch (if applicable).
* Check A/C switch and power relay (if applicable).
* Check park/neutral position switch (A/T).
* Check heated oxygen sensor.
* Check volume airflow sensor.
* Check fuel pressure.
* Check for disconnected or damaged vacuum hoses.
* Check for SFI system malfunction.
* Check idle air control (DC) motor (if applicable).
* Check idle air control (stepper) motor (if applicable).
* Check for fuel injector malfunction.
* Check for power transistor malfunction (if applicable).
* Check for vehicle speed sensor malfunction.
* Check for PCM malfunction.
* Ensure electrical harness, connectors and wires are not
broken, bent or loose.
ENGINE HESITATES OR POOR ACCELERATION
* Check intake air temperature sensor.
* Check engine coolant temperature sensor.
* Check barometric pressure sensor (if applicable).
* Check manifold absolute pressure sensor (if applicable).
* Check ignition switch.
* Check ignition coil.
* Check EGR control solenoid valve (if applicable).
* Check throttle position sensor.
* Check camshaft position sensor.
* Check crankshaft position sensor.
* Check power steering oil pressure switch (if applicable).
* Check A/C switch and power relay (if applicable).
* Check park/neutral position switch (A/T).
* Check heated oxygen sensor.
* Check volume airflow sensor.
* Check fuel pressure.
* Check for disconnected or damaged vacuum hoses.
* Check for SFI system malfunction.

* Check idle air control (DC) motor (if applicable).
* Check idle air control (stepper) motor (if applicable).
* Check for fuel injector malfunction.
* Check for power transistor malfunction (if applicable).
* Check A/C switch and power relay (if applicable).
* Check for PCM malfunction.
* Ensure electrical harness, connectors and wires are not
broken, bent or loose.
ENGINE SURGES
* Check engine coolant temperature sensor.
* Check EGR control solenoid valve (if applicable).
* Check fuel pressure.
* Check for fuel injector malfunction.
DETONATION OR KNOCKING
* Check for knock sensor malfunction (if applicable).
* Check volume airflow sensor.
* Check for engine cooling system problems.
* Check fuel quality.
* Check intake air temperature sensor.
* Check barometric pressure sensor (if applicable).
* Check manifold absolute pressure sensor (if applicable).
* Check ignition coil.
* Check power transistor (if applicable).
* Check for EGR system malfunction.
POOR FUEL MILEAGE
* Check intake air temperature sensor.
* Check engine coolant temperature sensor.
* Check barometric pressure sensor (if applicable).
* Check manifold absolute pressure sensor (if applicable).
* Check ignition switch.
* Check throttle position sensor.
* Check camshaft position sensor.
* Check crankshaft position sensor.
* Check power steering oil pressure switch (if applicable).
* Check A/C switch and power relay (if applicable).
* Check park/neutral position switch (A/T).
* Check heated oxygen sensor.
* Check volume airflow sensor.
* Check fuel pressure.
* Check for SFI system malfunction.
* Check idle air control (DC) motor (if applicable).
* Check idle air control (stepper) motor (if applicable).
* Check for fuel injector malfunction.
* Check for power transistor malfunction (if applicable).
INTERMITTENTS
INTERMITTENT PROBLEM DIAGNOSIS
Intermittent fault testing requires duplicating circuit or
component failure to identify problem. These procedures may lead to
computer setting a Diagnostic Trouble Code (DTC) which may help in
diagnosis.
If problem vehicle does not produce DTCs, monitor voltage or
resistance values using a DVOM while attempting to reproduce
conditions causing intermittent fault. A status change on DVOM