ignition MITSUBISHI MONTERO 1998 Service Manual

* Load Value (Displayed As Percent)
* Engine Coolant Temperature
* Short Term Fuel Trim (Displayed As Percent)
* Long Term Fuel Trim (Displayed As Percent)
* MAP Vacuum
* Engine RPM
* Vehicle Speed Sensor
* DTC During Data Recording
SELF-DIAGNOSTIC SYSTEM
SERVICE PRECAUTIONS
Before proceeding with diagnosis, following precautions must
be observed:
* Ensure vehicle has a fully charged battery and functional
charging system.
* Visually inspect connectors and circuit wiring being worked
on.
* DO NOT disconnect battery or PCM. This will erase any DTCs
stored in PCM.
* DO NOT cause short circuits when performing electrical tests.
This will set additional DTCs, making diagnosis of original
problem more difficult.
* DO NOT use a test light in place of a voltmeter.
* When checking for spark, ensure coil wire is NOT more than
1/4" from chassis ground. If coil wire is more than 1/4" from
chassis ground, damage to vehicle electronics and/or PCM may
result.
* DO NOT prolong testing of fuel injectors. Engine may
hydrostatically (liquid) lock.
* When a vehicle has multiple DTCs, always repair lowest number
DTC first.
VISUAL INSPECTION
Most driveability problems in the engine control system
result from faulty wiring, poor electrical connections or leaking air
and vacuum hose connections. To avoid unnecessary component testing,
perform a visual inspection before beginning self-diagnostic tests.
ENTERING ON-BOARD DIAGNOSTICS
NOTE: DO NOT skip any steps in self-diagnostic tests or incorrect
diagnosis may result. Ensure self-diagnostic test applies to
vehicle being tested.
DTCs may be retrieved by using a scan tool only. Proceed to
DTC retrieval method.
NOTE: Although other scan tools are available, Mitsubishi
recommends using Multi-Use Tester II (MUT II) scan tool.
Using Scan Tool
1) Refer to manufacturer's operation manual for instructions
in use of scan tool. Before entering on-board diagnostics, see
SERVICE PRECAUTIONS . Locate Data Link Connector (DLC) under instrument
panel, near steering column.
2) Turn ignition switch to OFF position. Connect scan tool to
DLC. Turn ignition switch to ON position. Read and record scan tool
self-diagnostic output. Proceed to TROUBLE CODE DEFINITION.

DTC P0155
Heated Oxygen Sensor (HO2S) heater circuit failure (bank 2,
sensor 1). Possible causes are: connector or harness, or HO2S.
DTC P0156
Heated Oxygen Sensor (HO2S) circuit failure (bank 2, sensor
2). Possible causes are: connector or harness, or HO2S.
DTC P0161
Heated Oxygen Sensor (HO2S) heater circuit failure (bank 2,
sensor 2). Possible causes are: connector or harness, or HO2S.
DTC P0170
Fuel trim failure (bank 1). Possible causes are: intake air
leaks, cracked exhaust manifold, faulty VAF sensor frequency, HO2S,
injector, fuel pressure, ECT, IAT or BARO pressure sensor.
DTC P0173
Fuel trim failure (bank 2). Possible causes are: intake air
leaks, cracked exhaust manifold, faulty VAF sensor frequency, HO2S,
injector, fuel pressure, ECT, IAT or BARO pressure sensor.
DTC P0201
Cylinder No. 1 injector circuit failure. Possible causes are:
connector or harness, or faulty injector.
DTC P0202
Cylinder No. 2 injector circuit failure. Possible causes are:
connector or harness, or faulty injector.
DTC P0203
Cylinder No. 3 injector circuit failure. Possible causes are:
connector or harness, or faulty injector.
DTC P0204
Cylinder No. 4 injector circuit failure. Possible causes are:
connector or harness, or faulty injector.
DTC P0205
Cylinder No. 5 injector circuit failure. Possible causes are:
connector or harness, or faulty injector.
DTC P0206
Cylinder No. 6 injector circuit failure. Possible causes are:
connector or harness, or faulty injector.
DTC P0300
Random misfire detected. Possible causes are: connector or
harness, faulty ignition coil, ignition power transistor, spark plug,
ignition circuit, injector, HO2S, compression pressure, timing belt,
air intake system, fuel pressure, or CKP sensor.
DTC P0301
Cylinder No. 1 misfire detected. Possible causes are:
connector or harness, faulty ignition coil, ignition power transistor,
spark plug, ignition circuit, injector, HO2S, compression pressure,
timing belt, air intake system, fuel pressure, or CKP sensor.
DTC P0302
Cylinder No. 2 misfire detected. Possible causes are:
connector or harness, faulty ignition coil, ignition power transistor,
spark plug, ignition circuit, injector, HO2S, compression pressure,
timing belt, air intake system, fuel pressure, or CKP sensor.

DTC P0303
Cylinder No. 3 misfire detected. Possible causes are:
connector or harness, faulty ignition coil, ignition power transistor,
spark plug, ignition circuit, injector, HO2S, compression pressure,
timing belt, air intake system, fuel pressure, or CKP sensor.
DTC P0304
Cylinder No. 4 misfire detected. Possible causes are:
connector or harness, faulty ignition coil, ignition power transistor,
spark plug, ignition circuit, injector, HO2S, compression pressure,
timing belt, air intake system, fuel pressure, or CKP sensor.
DTC P0305
Cylinder No. 5 misfire detected. Possible causes are:
connector or harness, faulty ignition coil, ignition power transistor,
spark plug, ignition circuit, injector, HO2S, compression pressure,
timing belt, air intake system, fuel pressure, or CKP sensor.
DTC P0306
Cylinder No. 6 misfire detected. Possible causes are:
connector or harness, faulty ignition coil, ignition power transistor,
spark plug, ignition circuit, injector, HO2S, compression pressure,
timing belt, air intake system, fuel pressure, or CKP sensor.
DTC P0325
Knock Sensor (KS) circuit failure. Possible causes are:
connector or harness, or faulty KS.
DTC P0335
Crankshaft Position (CKP) sensor circuit failure. Possible
causes are: connector or harness, or faulty CKP sensor.
DTC P0340
Camshaft Position (CMP) sensor circuit failure. Possible
causes are: connector or harness, or faulty CMP sensor.
DTC P0400
Exhaust Gas Recirculation (EGR) flow failure. Possible causes\
are: connector or harness, faulty EGR valve, EGR solenoid, EGR valve
control vacuum, or manifold differential pressure sensor.
DTC P0403
Exhaust Gas Recirculation (EGR) solenoid failure. Possible
causes are: connector or harness, or faulty EGR solenoid.
DTC P0420
Catalyst efficiency below threshold. Possible causes are:
cracked exhaust manifold, or faulty catalytic converter.
DTC P0421
Warm-up catalyst efficiency below threshold (bank 1).
Possible causes are: faulty exhaust manifold. If exhaust manifold is
okay, replace catalytic converter.
DTC P0431
Warm-up catalyst efficiency below threshold (bank 2).
Possible causes are: faulty exhaust manifold. If exhaust manifold is
okay, replace catalytic converter.
DTC P0442
Evaporative (EVAP) emission control system leak detected.
Possible causes are: connector or harness, faulty EVAP purge solenoid,

CLEARING DTCS
CAUTION: When battery is disconnected, vehicle computer and memory
systems may lose memory data. Driveability problems may
exist until computer systems have completed a relearn cycle.
To clear DTCs using a scan tool, refer to owners manual
supplied with scan tool. If scan tool is not available, DTCs may also
be cleared by disconnecting negative battery cable or PCM for at least
15 seconds, allowing PCM to clear DTCs. Reconnect negative battery
cable and check for DTCs to confirm repair.
PCM LOCATION
PCM LOCATION TABLE








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Application Location
Montero ........................... Right Front Kick Panel
3000GT ............................. Behind Center Console









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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.
TERMINAL IDENTIFICATION
NOTE: The following terminals are shown as viewed from component
side of connector. Vehicles are equipped with different
combinations of components. Not all components are used on
all models. To determine component usage, see appropriate
wiring diagram in L - WIRING DIAGRAMS article.
TERMINAL IDENTIFICATION DIRECTORY TABLE









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Connector See
ASD/Fuel Pump/MFI Relay ...................... Fig. 1 or 2
CKP/CMP Sensor ............................ Fig. 3, 4 or 5
DLC ............................................... Fig. 6
ECT Sensor ........................................ Fig. 7
EVAP Purge Solenoid ............................... Fig. 8
EVAP Vent Solenoid ................................ Fig. 9
Fuel Injector ....................... Fig. 10, 11, 12 or 13
Fuel Pump ................................... Fig. 14 or 15
Fuel Pump Control/Relay Module .................... Fig. 16
FTDP Sensor ...................................... Fig. 17
Generator Field .................................. Fig. 18
HO2S ............................................. Fig. 19
IAC Motor ........................................ Fig. 20
Ignition Coil .......................... Fig. 21, 22 or 23
Ignition Failure Sensor .......................... Fig. 24
Ignition Power Transistor .................. Fig. 25 or 26
KS ............................................... Fig. 27
MDP Sensor ....................................... Fig. 28
PCM .............................................. Fig. 29

Fig. 19: Identifying HO2S Terminals (Front Or Rear)
Courtesy of Mitsubishi Motor Sales of America
Fig. 20: Identifying IAC Motor Terminals
Courtesy of Mitsubishi Motor Sales of America
Fig. 21: Identifying Ignition Coil Terminals (3000GT DOHC)
Courtesy of Mitsubishi Motor Sales of America

Fig. 22: Identifying Ignition Coil Terminals (3000GT SOHC)
Courtesy of Mitsubishi Motor Sales of America

Fig. 23: Identifying Ignition Coil Terminals (Montero)
Courtesy of Mitsubishi Motor Sales of America

Fig. 24: Identifying Ignition Failure Sensor Terminals
Courtesy of Mitsubishi Motor Sales of America
Fig. 25: Identifying Ignition Coil Terminals (Montero & 3000GT DOHC)
Courtesy of Mitsubishi Motor Sales of America
Fig. 26: Identifying Ignition Coil Terminals (3000GT SOHC)
Courtesy of Mitsubishi Motor Sales of America

Fig. 36: Identifying VIC Valve Position Sensor Terminals
Courtesy of Mitsubishi Motor Sales of America
Fig. 37: Identifying VSS Terminals
Courtesy of Mitsubishi Motor Sales of America
DIAGNOSTIC TESTS
CAUTION: Ensure ignition switch is in OFF position when disconnecting

special patterns probe to VAF sensor connector terminal No. 3 or to
PCM connector terminal No. 61.
2) Start engine. Verify waveform high frequency and low
frequency patterns are of about the same length (time). Verify
wavelength decreases and frequency increases as engine RPM increases.
If conditions are not as specified, replace VAF sensor. If conditions
are as specified, go to step 4).
3) Warm vehicle to normal operating temperature. Ensure
headlights and accessories are off. Using scan tool, read VAF sensor
frequency value (item 12). See VOLUME AIRFLOW SENSOR VALUES table.
Frequency should increase when engine is raced. If values are not as
specified, replace VAF sensor. If values are as specified, turn
ignition switch to off position and disconnect VAF sensor connector.
Go to next step.
VOLUME AIRFLOW SENSOR VALUES TABLE









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Application Hz @ 700 RPM Hz @ 2500 RPM
Montero ................. 25-51 ................. 80-120
3000GT
DOHC
Non-Turbo ........... 24-50 ................. 71-111
Turbo ............... 26-52 ................. 93-133
SOHC .................. 21-47 .................. 57-97









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4) On 3000GT, go to next step. On Montero, disconnect MFI
relay connector. Using DVOM, check for continuity between VAF sensor
connector terminal No. 4 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) Using DVOM, check for continuity between chassis ground
and VAF sensor connector terminal No. 5. If continuity does not exist,
repair wiring harness as necessary. If continuity exists, go to next
step.
6) Ensure ignition switch is in OFF position. Disconnect PCM
connector. Ground PCM connector terminal No. 19. Using DVOM, check for
continuity between chassis ground and VAF sensor connector terminal
No. 7. If continuity does not exist, repair wiring harness as
necessary. If continuity exists, go to next step.
7) On 3000GT, go to next step. On Montero, ground PCM
connector terminal No. 61. Using DVOM, check for continuity between
chassis ground and VAF sensor connector terminal No. 3. If continuity
does not exist, repair wiring harness as necessary. If continuity
exists, turn ignition switch to ON position and go to step 9).
8) Turn ignition switch to ON position. Using DVOM, check
voltage between chassis ground and VAF sensor connector terminal No.
4. If battery voltage does not exist, repair wiring harness as
necessary. If battery voltage exists, go to next step.
9) Using DVOM, check voltage between chassis ground and VAF
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.
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 P0105: BAROMETRIC (BARO) PRESSURE SENSOR CIRCUIT FAILURE
NOTE: BARO pressure sensor is built into Volume Airflow (VAF)
sensor. For DTC P0105 test purposes, VAF sensor will be