1998 MITSUBISHI MONTERO check engine light

ON-VEHICLE TESTING
GENERATOR TO BATTERY CONTINUITY TEST
NOTE: Check generator wiring harness connections and drive belt
tension and ensure battery is fully charged before
performing test.
1) Turn ignition off. Disconnect negative battery cable.
Remove output lead from generator terminal "B". See Fig. 1. Install a
100-amp or 130-amp ammeter in series with terminal "B" and
disconnected output lead. Install positive lead of ammeter to terminal
"B" and negative lead to disconnected output wire.
Fig. 1: Identifying Generator Terminals (Typical)
Courtesy of Mitsubishi Motor Sales of America
2) Install positive lead of digital voltmeter to terminal "B"
and negative lead to positive battery terminal. Install a tachometer
and reconnect negative battery cable.
3) Start and operate engine at 2500 RPM. Turn accessories on
and adjust engine speed until ammeter indicates slightly greater than
30 amps, and note voltmeter reading. If voltmeter indicates .3 volt or
less, system is okay.
4) If voltage is greater than .3 volt, check wiring between
generator terminal "B", fusible link and positive battery terminal. If
terminal is not sufficiently tight or if harness is discolored due to
overheating, repair as necessary and retest.

GENERATOR OUTPUT TEST
NOTE: A slightly discharged battery should be used, as a fully
charged battery may not allow full generator output.
1) Turn ignition off. Disconnect negative battery cable.
Disconnect generator output wire from terminal "B". Connect positive
lead of 100-amp ammeter to terminal "B" and negative lead to
disconnected output lead.
CAUTION: Tighten each connection securely, as heavy current flow will
exist. DO NOT use clips on ammeter. An inductive-type
ammeter is recommended.
2) Connect positive voltmeter lead (0-20 volts) to generator\
terminal "B" and negative lead to ground. Install a tachometer and
reconnect negative battery cable.
3) Ensure voltmeter indicates battery voltage. If voltage is
not present, check for open circuit in wire between generator terminal
"B" and positive battery terminal. Check grounds and fusible link.
4) Start engine and turn headlights on. Set headlights at
high beam and heater blower switch on HIGH. Increase engine speed to
2500 RPM and note generator output current on ammeter. Minimum output
should be within specification. See
GENERATOR MINIMUM OUTPUT SPECIFICATIONS table.
NOTE: Output voltage changes with electrical load and temperature.
Ensure proper electrical load is applied while checking
output. Nominal output may not be obtained if generator or
ambient temperature is excessive. Allow generator or
temperature to cool, and recheck output. Generator output is
stamped on metal plate attached to generator case.
5) If minimum output is not obtained and generator wiring is
okay, repair generator. Operate engine at idle speed after the test.
GENERATOR MINIMUM OUTPUT SPECIFICATIONS TABLE









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Application Amps
Diamante ............................................. 110
Eclipse
2.0L Non-Turbo ...................................... 90
2.0L Turbo .......................................... 75
2.4L ................................................ 90
Galant ................................................ 90
Mirage ................................................ 80
Montero .............................................. 100
Montero Sport
2.4L ................................................ 60
3.0L ................................................ 85
3000GT
DOHC ............................................... 110
SOHC ................................................ 90









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REGULATED VOLTAGE TEST
NOTE: Ensure battery is fully charged and proper drive belt
tension exists.
1) Turn ignition switch off. Disconnect negative battery
cable. Connect positive voltmeter lead to terminal "S" of generator.

See Fig. 1 . Connect negative voltmeter lead to ground.
2) Disconnect generator output wire from terminal "B".
Install a 100-amp ammeter in series with terminal "B" and disconnected
output lead. Connect positive lead of ammeter to terminal "B" and
negative lead to disconnected output wire. Install a tachometer, and
reconnect negative battery cable.
3) Turn ignition switch on and ensure voltmeter indicates
battery voltage. If voltage is not present, check for open in wire
between generator terminal "S" and positive battery terminal. Check
for blown fusible link.
4) Start engine. Ensure all lights and accessories are off.
Operate engine at 2500 RPM and read voltmeter when generator output
current drops to 10 amps or less. Voltage regulator is okay if voltage
output is within specification. See REGULATOR VOLTAGE SPECIFICATIONS
table.
REGULATOR VOLTAGE SPECIFICATIONS TABLE









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Ambient Temperature Voltage
-4
F (-20C) ................................... 14.2-15.4
68F (20C) .................................... 13.9-14.9
140F (60C) ................................... 13.4-14.6
176F (80C) ................................... 13.1-14.5








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GENERATOR RELAY TEST
NOTE: Information for all other models is not available from
manufacturer at time of publication.
Diamante & Mirage
Remove generator relay. On Diamante, relay is located in
relay box in engine compartment near battery. On Mirage, relay is
located in relay box in engine compartment between battery and strut
tower. On both models, connect positive lead of ohmmeter to relay
terminal No. 4. See WIRING DIAGRAMS. Connect negative lead of ohmmeter
to relay terminal No. 2. Continuity should be present. Switch ohmmeter
lead locations. Continuity should not be present. Replace generator
relay if continuity is not as specified.
BENCH TESTING
RECTIFIER ASSEMBLY
1) Using ohmmeter, check for continuity between diodes and
stator coil lead connection. See Fig. 2. Reverse leads. If continuity
is present in both directions, diode is shorted. Replace rectifier
assembly.
2) To check entire diode assembly, use an ohmmeter to check
for continuity between both ends of each diode. See Fig. 2. Switch
ohmmeter leads. Continuity should be present in one direction only. If
continuity is not as specified, diode is defective. Replace rectifier
assembly.

See TURBOCHARGER under AIR INDUCTION SYSTEMS.
FUEL SYSTEM
FUEL DELIVERY
NOTE: For fuel system pressure testing, see
F - BASIC TESTING article.
Fuel Pressure Regulator Control Solenoid Valve (Turbo Models)
See G - TESTS W/CODES article.
FUEL CONTROL
Fuel Injectors
See G - TESTS W/CODES article.
IDLE CONTROL SYSTEM
ELECTRICAL LOAD SWITCH
3000GT (DOHC)
1) Turn ignition off. Disconnect PCM connector. See
POWERTRAIN CONTROL MODULE (PCM) LOCATION table under COMPUTERIZED
ENGINE CONTROLS. Go to next step.
2) Turn headlights on. Using DVOM, check voltage between PCM
connector terminal No. 58 and chassis ground. If battery voltage is
present, turn headlights off and go to next step. If battery voltage
is not present, check and repair circuit between headlight relay
connector and PCM connector.
3) Turn defogger switch on. Using DVOM, check voltage between
PCM connector terminal No. 58 and chassis ground. If battery voltage
is present, turn defogger switch off and go to next step. If battery
voltage is not present, check and repair circuit between defogger
relay connector and PCM connector.
4) Turn blower switch on. Using DVOM, check voltage between
PCM connector terminal No. 58 and chassis ground. If battery voltage
is present, turn blower switch off and go to next step. If battery
voltage is not present, check and repair circuit between blower switch
connector and PCM connector.
5) If battery voltage is present and preceding tests do not
show any system or component malfunction and PCM is suspected,
substitute PCM with known-good unit and retest system.
IDLE AIR CONTROL (IAC) MOTOR
For testing procedures, see G - TESTS W/CODES article.
IGNITION SYSTEM
NOTE: For basic ignition checks, see F - BASIC TESTING article.
TIMING CONTROL SYSTEMS
Camshaft Position Sensor
See G - TESTS W/CODES article.
Crankshaft Position Sensor
See G - TESTS W/CODES article.

Eclipse 2.0L Non-Turbo With A/T
Disconnect sensor harness connector. Check resistance between
sensor terminals. Resistance should be 300-1200 ohms. Replace sensor
as necessary.
OIL PRESSURE GAUGE
Circuit Test (Eclipse, Montero & 3000GT)
1) Disconnect oil pressure gauge wiring connector from
sending unit inside engine compartment. Connect a 12-volt test light
between harness connector terminal and ground. Turn ignition on, but
DO NOT start engine.
2) If test light comes on and gauge needle moves, go to GAUGE
RESISTANCE TEST. If test light does not come on and gauge needle does
not move, repair wiring to sending unit.
Gauge Resistance Test (Eclipse, Montero & 3000GT)
1) Remove instrument cluster from instrument panel. See
INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. On 3000GT, remove air
distribution duct and combination gauges.
2) On all models, check continuity between oil pressure gauge
terminals. See Fig. 17, 18 or 19. See
OIL PRESSURE GAUGE RESISTANCE SPECIFICATIONS table. If resistance is
not within specification, replace oil pressure gauge.
OIL PRESSURE GAUGE RESISTANCE SPECIFICATIONS TABLE









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Application Ohms
Eclipse & 3000GT ................................... 40-44
Montero ............................................... 50









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Fig. 17: Oil Pressure Gauge Resistance Test Terminals (Eclipse)
Courtesy of Mitsubishi Motor Sales of America

speedometer.
TEMPERATURE GAUGE
CAUTION: DO NOT connect sender wire directly to ground during test.
Circuit Test
1) Disconnect temperature sender wire from sending unit.
Connect a 12-volt, 3.4-watt test light between connector terminal and
ground. Turn ignition switch to ON position.
2) If test light flashes and temperature gauge needle moves,
go to SENSOR RESISTANCE TEST. If test light does not flash or gauge
needle does not move, repair wiring to sending unit.
Sensor Resistance Test
1) Remove Engine Coolant Temperature (ECT) sensor from
engine. See COMPONENT LOCATIONS . Place sending unit in 158
F (70C)
water. Check sensor resistance using ohmmeter.
2) ECT sensor resistance should be 90-117 ohms. If ECT sensor
resistance is okay, go to GAUGE RESISTANCE TEST. Replace ECT sensor if
resistance is not as specified.
Gauge Resistance Test
1) Remove instrument cluster. See INSTRUMENT CLUSTER under
REMOVAL & INSTALLATION. On 3000GT, remove air distribution duct and
combination gauges.
2) On all models, check resistance between temperature gauge
terminals at rear of cluster or combination gauges. See
TEMPERATURE GAUGE RESISTANCE SPECIFICATIONS table. See Fig. 21, 22,
23, 24, 25, 26, 27 or 28.
TEMPERATURE GAUGE RESISTANCE SPECIFICATIONS TABLE









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Application ( 1) Terminals Ohms
Eclipse ............... "A" & "B" .............. 161-197
Eclipse ............... "A" & "C" ................ 51-57
Eclipse ............... "B" & "C" .............. 210-256
Galant ................ "B" & "C" .................. ( 2)
Mirage ................ "A" & "B" ................ 86-95
Mirage ................ "A" & "C" .............. 168-206
Mirage ................ "B" & "C" .............. 222-272
Montero ............... No. 4 & 8 .............. 103-128
Montero ............... No. 4 & 9 .............. 221-271
Montero ............... No. 8 & 9 .............. 130-160
Montero Sport ......... "A" & "B" ................... 88
Montero Sport ......... "A" & "C" .................. 103
Montero Sport ......... "B" & "C" .................. 191
3000GT ................ "A" & "B" ................... 51
3000GT ................ "A" & "C" .................. 139
3000GT ................ "B" & "C" .................. 190
( 1) - See Fig. 21, 22, 23, 24, 25, 26, 27 or 28.
( 2) - With positive battery voltage applied to terminal "A",
battery ground applied to terminal "C" and a 50-ohm
resistor connected between battery ground and terminal
"B", needle should be about 1/4 position on gauge.









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Resistance Test (Montero Only)
Using an ohmmeter, check resistance between voltmeter
terminals. See Fig. 30. Resistance should be 380-460 ohms.
Fig. 30: Identifying Voltmeter Resistance Test Terminals (Montero)
Courtesy of Mitsubishi Motor Sales of America
Voltage Test (3000GT Only)
Start engine, and let it idle. Connect voltmeter to battery.
Compare voltage reading of test voltmeter to voltage reading of
vehicle voltmeter. Voltage variation should not exceed 0.5 volt (plus
or minus). Replace instrument cluster voltmeter if voltage reading is
not as specified.
FOGLIGHT SWITCH TEST
NOTE: Montero Sport is not equipped with foglights.
Eclipse
Remove foglight switch from instrument panel. Disconnect
switch connector. Using an ohmmeter, check switch continuity. With
switch in OFF position, continuity should exist between terminals No.
1 and 3. With switch in ON position, continuity should exist between
terminals No. 1 and 3, and between terminals No. 4 and 5. See Fig. 31.
If continuity is not as specified, replace switch.
Galant & Mirage
Remove foglight switch from instrument panel. Disconnect
switch connector. Using an ohmmeter, check switch continuity. With
switch in OFF position, continuity should exist between terminals No.
1 and 2. With switch in ON position, continuity should exist between
terminals No. 1 and 2, terminals No. 3 and 4, and terminals No. 5 and
6. See Fig. 31. If continuity is not as specified, replace switch.

Remove relay from engine compartment fuse/relay box. Using an
ohmmeter, check relay continuity. With battery voltage not supplied to
relay, continuity should exist between terminals No. 1 and 3. With
positive battery terminal connected to relay terminal No. 1 and
negative battery terminal connected to relay terminal No. 3,
continuity should exist between terminals No. 4 and 5. See Fig. 33. If
continuity is not as specified, replace relay.
Fig. 33: Identifying Foglight Relay Connector Terminals
Courtesy of Mitsubishi Motor Sales of America
HAZARD LIGHT SWITCH TEST
Eclipse, Mirage & Montero Sport
Remove hazard light switch from instrument panel. Disconnect
switch connector. Using an ohmmeter, check switch continuity. With
switch in OFF position, continuity should exist between terminals No.
5 and 7, and between terminals No. 9 and 10. With switch in ON
position, continuity should exist between terminals No. 1, 2 and 4,
between terminals No. 5 and 6, and between terminals No. 9 and 10. See
Fig. 34 . If continuity is not as specified, replace switch.
Galant