1998 MITSUBISHI MONTERO engine coolant

3) If radiator fan and condenser fan operate in all speeds
except high, check appropriate high speed relay. See COMPONENT TESTS.
See WIRING DIAGRAMS . If high speed relay is okay, check PCM. See
appropriate G - TESTS W/CODES article in ENGINE PERFORMANCE.
* G - TESTS W/CODES - 1997
* G - TESTS W/CODES - 1998
4) To confirm radiator fan or condenser fan operation, see
appropriate FAN OPERATING MODE (GALANT) table. If fan operation is not\
as specified, check wiring harness for opens or shorts. Repair as
necessary.
FAN OPERATING MODE (GALANT) ( 1)









\









\









\









\









\









\









\







Coolant Radiator Condenser
Temp. F (C) Fan Speed Fan Speed
28 MPH ( 2)
203 (95) ( 2) ................ Off .......................... Off
203-221 (95-105) ............ Low .......................... Low\
221 (105) ( 3) .............. High ......................... High
28-50 MPH
194 (90) ( 2) ................ Off .......................... Off
194-221 (90-105) ............ Low .......................... Low\
221 (105) ( 3) .............. High ......................... High
50 MPH ( 3)
221 (105) ( 2) ............... Off .......................... Off
221 (105) ( 3) .............. High ......................... High
Any Speed ( 4)
221 (105) ( 2) ............... Low .......................... Low
221 (105) ( 3) .............. High ......................... High
( 1) - A/C request switch is turned off.
( 2) - Approximate vehicle speed/coolant temperature or less.
( 3) - Approximate vehicle speed/coolant temperature or more.
( 4) - A/C request switch is turned on.









\









\









\









\









\









\









\







NOTE: Operation of radiator and condenser fans is controlled by
vehicle Powertrain Control Module (PCM). Based on vehicle
speed, coolant temperature and A/C operation request, PCM
will command low, medium or high speed fan operation.
Mirage
1) If only the radiator fan does not operate, check fusible
link No. 5 (30-amp) located in engine compartment relay box. If only
the condenser fan does not operate, check fusible link No. 2 (100-amp)\
and dedicated fuse No. 1 (25-amp) located in engine compartment relay
box. See WIRING DIAGRAMS . Repair as necessary.
2) If fusible links and dedicated fuse are okay, check
appropriate fan relay and/or fan motor for proper operation. See
COMPONENT TESTS. See WIRING DIAGRAMS. If fan relay and motor are okay,
check PCM. See appropriate G - TESTS W/CODES article in ENGINE
PERFORMANCE.
* G - TESTS W/CODES - 1.5L - 1997
* G - TESTS W/CODES - 1.8L - 1997
* G - TESTS W/CODES - 1998
3) To confirm radiator fan or condenser fan operation, see
appropriate FAN OPERATING MODE (MIRAGE) table. If fan operation is not\
as specified, check wiring harness for opens or shorts. Repair as

necessary.
FAN OPERATING MODE (MIRAGE)









\









\









\









\









\









\









\







Power Circuit
Coolant Operating Radiator Condenser
Temp.
F (C) RAD/COND Fan Speed Fan Speed
203 (95) ( 1) ( 2) ...... Off/Off ....... Off ................ Off
203-221 (95-105) ( 1) ... On/Off ........ On ................ Off
221 (105) ( 1) ( 3) ...... On/On ......... On ................. On
All Temp. ( 4) .......... On/On ......... On ................. On
( 1) - A/C request switch is turned off.
( 2) - Approximate coolant temperature or less.
( 3) - Approximate coolant temperature or more.
( 4) - A/C request switch is turned on.









\









\









\









\









\









\









\







NOTE: Operation of radiator and condenser fans is controlled by
vehicle Powertrain Control Module (PCM). Based on vehicle
speed, coolant temperature and A/C operation request, PCM
will command low, medium or high speed fan operation.
3000GT
1) If neither the radiator fan nor the condenser fan operate,
check fusible link No. 5 (40-amp). See WIRING DIAGRAMS. If only the
condenser fan does not operate, check dedicated fuse No. 8 (20-amp).
2) If the condenser fan operates in all speeds except low and
A/C compressor clutch does not enter the ON state, check for A/C
compressor lock controller unit output signal. If the A/C compressor
clutch does enter the ON state, check condenser fan low speed relay
operation.
3) If the radiator fan and the condenser fan operate in all
speeds except high, check PCM. See appropriate G - TESTS W/CODES
article in ENGINE PERFORMANCE. If fan operation is not as specified,
check wiring harness for opens or shorts. Repair as necessary.
* G - TESTS W/CODES - NON-TURBO - 1997
* G - TESTS W/CODES - TURBO - 1997
* G - TESTS W/CODES - 1998
4) To confirm radiator fan or condenser fan operation, see
appropriate FAN OPERATING MODE (3000GT) table. If fan operation is not\
as specified, check wiring harness for opens or shorts. Repair as
necessary.
FAN OPERATING MODE (3000GT)









\









\









\









\









\









\









\







Power Circuit
Coolant Operating Radiator Condenser
Temp.
F (C) Low/High Fan Speed Fan Speed
50 MPH ( 1) ( 2)
203 (95) ( 2) ........ Off/Off ....... Off ................ Off
203-221 (95-105) ..... On/Off ....... Low ................ Off\
221 (105) ( 3) ........ On/On ........ High .............. High
50 MPH ( 1) ( 3)
221 (105) ( 2) ....... Off/Off ....... Off ................ Off
221 (105) ( 3) ........ On/On ........ High .............. High
All Speeds
221 (105) ( 2) ........ On/Off ....... Low ................ Low
221 (105) ( 3) ........ On/On ........ High .............. High

distributor.
2) Start engine and warm engine until engine temperature
coolant is 176-203
F (80-95C). Turn engine off. Insert a paper clip
in engine speed detection connector terminal No. 3. See Fig. 1.
Connect a primary voltage detection-type tachometer to paper clip.
Fig. 1: Locating Engine Speed Detection Connector (Diamante)
Courtesy of Mitsubishi Motor Sales of America
3) Install a timing light. Start engine and allow it to idle.
Ensure engine curb idle speed is about 700 RPM. Curb idle speed is
automatically controlled by Idle Air Control (IAC) system. If curb
idle speed is not as specified, see DTC P0505 in G - TESTS W/CODES
article.
CAUTION: MFI system actuator test must be cancelled or test will
continue to run for 27 minutes. Driving vehicle under this
condition may damage engine.
4) Turn engine off. Connect scan tool to Data Link Connector
(DLC). DLC is located below left side of dash, near steering column.
See Fig. 2 . Start engine and allow it to idle. Using scan tool, select
MFI SYSTEM ACTUATOR TEST, then select item 17 (BASIC IGNITION TIMING).\
Press "Y" and read basic ignition timing value. See
IGNITION TIMING SPECIFICATIONS table. If basic ignition timing is
within specification, go to next step. If basic ignition timing is not
within specification, cancel MFI system actuator test. See DTC P0335
in G - TESTS W/CODES article.
5) Read actual ignition timing value. If actual ignition
timing is not within specification, cancel MFI system actuator test.
See DTC P0335 in G - TESTS W/CODES article.

coolant is 176-203F (80-95C). Turn engine off. Insert a paper clip
in engine speed detection connector. See Fig. 3. Connect a tachometer
to paper clip.
Fig. 3: Locating Engine Speed Detection Connector (3000GT - DOHC)
Courtesy of Mitsubishi Motor Sales of America
3) Install a timing light. Start engine and allow it to idle.
Using tachometer, read curb idle (RPM). Multiply RPM reading by 3 to
obtain actual curb idle speed. Ensure curb idle speed is 600-700 RPM.
Turn engine off. Curb idle speed is automatically controlled by Idle
Air Control (IAC) system. If curb idle speed is not as specified, see
DTC P0505 in G - TESTS W/CODES article.
4) Disconnect waterproof female connector from Brown ignition
timing check connector. See Fig. 4. Using a jumper wire, ground
ignition timing check terminal to read basic ignition timing. Using
timing light, read basic ignition timing value. See
IGNITION TIMING SPECIFICATIONS table. If basic ignition timing is
within specification, go to next step. If basic ignition timing is not
within specification, see DTC P0335 in G - TESTS W/CODES article.
5) Remove jumper wire to read actual ignition timing. Using
timing light, read actual ignition timing value. If actual ignition
timing is not within specification, see DTC P0335 in G - TESTS W/CODES
article.

Fig. 4: Locating Ignition Timing Check Connector
Courtesy of Mitsubishi Motor Sales of America
3000GT (SOHC)
1) Ignition timing is controlled by Powertrain Control Module
(PCM) and is not adjustable. Manufacturer provides procedure for
checking timing.
2) Start engine and warm engine until engine temperature
coolant is 176-203
F (80-95C). Turn engine off. Insert a paper clip
in noise filter connector. See Fig. 5. Connect a tachometer to paper
clip.
Fig. 5: Locating Noise Filter Connector
Courtesy of Mitsubishi Motor Sales of America
3) Install a timing light. Start engine and allow it to idle.
Using tachometer, read curb idle speed (RPM). Ensure curb idle speed

Mirage &
Montero Sport ... Behind Right Side Of Instrument Panel (Glove Box)\
Montero ..................................... Right Front Kick Panel
All Others ................................... Behind Center Console









\









\









\









\









\









\









\







NOTE: Components are grouped into 2 categories. The first category
covers INPUT DEVICES, which control or produce voltage
signals monitored by Powertrain Control Module (PCM). The
second category covers OUTPUT SIGNALS, which are components
controlled by PCM.
INPUT DEVICES
Vehicles are equipped with different combinations of input
devices. Not all input devices are used on all models. To determine
input device usage on specific models, see appropriate wiring diagram
in L - WIRING DIAGRAMS article. The following are available input
devices.
Air Conditioning Switch
When A/C is turned on, signal is sent to PCM. With engine at
idle, PCM increases idle speed through Idle Air Control (IAC) motor.
Airflow Sensor Assembly
Assembly is mounted inside air cleaner, and incorporates
barometric pressure sensor, intake air temperature sensor and volume
airflow sensor.
Barometric (BARO) Pressure Sensor
Sensor is incorporated into airflow sensor assembly. Sensor
converts barometric pressure to electrical signal, which is sent to
PCM. PCM adjusts air/fuel ratio and ignition timing according to
altitude.
Camshaft Position (CMP) Sensor
On SOHC engines equipped with a distributor, CMP sensor is
located in distributor. On Eclipse (Turbo) and DOHC V6 engines, sensor\
is located beside camshaft, in front of engine. On all other engines,
CMP sensor is a separate unit mounted in place of distributor. PCM
determines TDC based on pulse signals received from sensor, and then
controls MFI timing.
Closed Throttle Position (CTP) Switch
CTP switch is located in the Throttle Position (TP) sensor.
PCM senses whether accelerator pedal is depressed or not. High voltage
(open) or low voltage (closed) signal is input to PCM, which then
controls Idle Air Control (IAC) motor based on input signal.
Crankshaft Position (CKP) Sensor
CKP sensor is located in distributor on SOHC engines, except
1.5L 4-cylinder with California emissions. On DOHC 4-cylinder, DOHC V6
and 1.5L 4-cylinder engines with California emissions, CKP sensor is
located beside crankshaft, in front of engine. PCM determines
crankshaft position on pulse signals received from sensor, and then
controls MFI timing and ignition timing.
Engine Coolant Temperature (ECT) Sensor
ECT sensor converts coolant temperature to electrical signal
for use by PCM. PCM uses coolant temperature information to control
fuel enrichment when engine is cold.
Heated Oxygen Sensor (HO2S)

usage on specific models, see appropriate wiring diagram in
L - WIRING DIAGRAMS article. For theory and operation on each
output component, refer to system indicated after component.
Data Link Connector (DLC)
See SELF-DIAGNOSTIC SYSTEM .
EGR Control Solenoid Valve
See EXHAUST GAS RECIRCULATION (EGR) CONTROL under EMISSION
SYSTEMS.
Fuel Injectors
See FUEL CONTROL under FUEL SYSTEM.
Fuel Pressure Control Solenoid Valve (Turbo)
See FUEL DELIVERY under FUEL SYSTEM.
Fuel Pressure Regulator
See FUEL DELIVERY under FUEL SYSTEM.
Idle Air Control (IAC) Motor
See IDLE SPEED under FUEL SYSTEM.
Malfunction Indicator Light
See SELF-DIAGNOSTIC SYSTEM .
Power Transistor(s) & Ignition Coils
See IGNITION SYSTEMS .
Purge Control Solenoid Valve
See EVAPORATIVE CONTROL under EMISSION SYSTEMS.
Wastegate Control Solenoid Valve
See TURBOCHARGED ENGINES under AIR INDUCTION SYSTEM.
FUEL SYSTEM
FUEL DELIVERY
Electric fuel pump, located in gas tank, feeds fuel through
in-tank fuel filter, external fuel filter (located in engine
compartment) and fuel injector rail.
Fuel Pump
Fuel pump consists of a motor-driven impeller. Pump has an
internal check valve to maintain system pressure, and a relief valve
to protect fuel pressure circuit. Pump receives voltage supply from
MFI control relay.
Fuel Pressure Control Solenoid Valve (Turbo)
Valve prevents rough idle due to fuel percolation. On engine
restart, if engine coolant or intake air temperature reaches a preset
value, PCM applies voltage to fuel pressure control solenoid valve for
2 minutes after enginerestart. Valve will open, allowing atmospheric
pressure to be applied to fuel pressure regulator diaphragm. This
allows maximum available fuel pressure at injectors, enriching fuel
mixture and maintaining stable idle at high engine temperatures.
Fuel Pressure Regulator
Located on fuel injector rail, this diaphragm-operated relief
valve adjusts fuel pressure according to engine manifold vacuum.
As engine manifold vacuum increases (closed throttle), fuel

pressure regulator diaphragm opens relief valve, allowing pressure to
bleed off through fuel return line, reducing fuel pressure.
As engine manifold vacuum decreases (open throttle), fuel
pressure regulator diaphragm closes valve, preventing pressure from
bleeding off through fuel return line, increasing fuel pressure.
FUEL CONTROL
Fuel Injectors
Fuel is supplied to engine through electronically pulsed
(timed) injector valves located on fuel rail(s). PCM controls amount\
of fuel metered through injectors based on information received from
sensors.
IDLE SPEED
Air Conditioning (A/C) Relay
When A/C is turned on with engine at idle, PCM signals IAC
motor to increase idle speed. To prevent A/C compressor from switching
on before idle speed has increased, PCM momentarily opens A/C relay
circuit.
Idle Air Control (IAC) Motor
Motor controls pintle-type air valve to regulate volume of
intake air at idle.
During start mode, PCM controls idle intake air volume
according to Engine Coolant Temperature (ECT) sensor input. After
starting, with idle position switch activated (throttle closed), fast
idle speed is controlled by IAC motor and fast idle air control valve
(if equipped).
When idle switch is deactivated (throttle open), IAC motor
moves to a preset position in accordance with ECT sensor input.
PCM signals IAC motor to increase engine RPM in the following
situations: A/T (if applicable) is shifted from Neutral to Drive, A/C
is turned on, or power steering pressure reaches a preset value.
IGNITION SYSTEMS
DIRECT IGNITION SYSTEM (DIS)
Depending on number of cylinders, ignition system is a 2 or
3-coil, distributorless ignition system. On Eclipse (Turbo) and DOHC
V6 engines, Camshaft Position (CMP) sensor is located beside camshaft,\
in front of engine. On all other engines equipped with DIS, CMP sensor
is a separate unit mounted in place of distributor. On DOHC 4-
cylinder, DOHC V6 and 1.8L 4-cylinder engines with California
emissions, Crankshaft Position (CKP) sensor is located beside
crankshaft, in front of engine. PCM determines TDC based on pulse
signals received from sensors and then controls MFI and ignition
timing.
Power Transistors & Ignition Coils
Based on crankshaft position and CMP sensor inputs, PCM
controls timing and directly activates each power transistor to fire
coils. On 4-cylinder engines, power transistor "A" controls primary
current of ignition coil "A" to fire spark plugs on cylinders No. 1
and No. 4 at the same time. Power transistor "B" controls primary
current of ignition coil "B" to fire spark plugs on cylinders No. 2
and No. 3 at the same time. On V6 engines, companion cylinders No. 1
and 4, 2 and 5, and 3 and 6 are fired together.
On all models, although each coil fires 2 plugs at the same
time, ignition takes place in only one cylinder, since the other