1998 MITSUBISHI MONTERO Fuel Pump

system.
3) Using scan tool, read Fuel Tank Differential Pressure
(FTDP) sensor (item 73). Using hand-held pressure/vacuum pump, 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 8).
4) Disconnect EVAP canister purge hose. Connect Purge Flow
Indicator (MB995061) between EVAP canister and disconnected hose. Turn\
engine on and allow it to reach operating temperature. Turn all lights
and accessories off. Place transmission in Park or Neutral. Observe
purge flow indicator while increasing engine RPM several times. If
purge flow indicator reads less than 2.5 SCFH (20 cm(3)/sec), check
EVAP canister purge hose and EVAP canister port for clogging. If hose
and port are okay, check EVAP purge solenoid. See DTC P0443. If
solenoid is okay, replace EVAP canister. Go to step 20).
5) Using scan tool, read Engine Coolant Temperature (ECT)
sensor temperature (item 21). Compare scan tool reading with
temperature gauge reading. If readings are about the same, go to next
step. If readings are not about the same, go to DTC P0115 test.
6) Using a thermometer, check engine compartment ambient
temperature. Using scan tool, read Intake Air Temperature (IAT) sensor\
temperature (item 13). Compare IAT sensor and thermometer readings. If\
readings are not about the same, go to DTC P0110 test. If readings are
about the same, go to next step.
7) Using scan tool, read Power Steering Pressure (PSP) switc\
h
status (item 27). Switch status should read ON when steering wheel is
turned. If switch status is as specified, go to step 20). If switch
status is not as specified, go to DTC P0551 test.
8) Remove fuel cap. Install a fuel tank filler tube adapter
in place of fuel cap. Plug fuel filler tube adapter hose. Disconnect
and plug air filter-to-EVAP vent solenoid hose at air filter.
Disconnect intake manifold plenum-to-EVAP purge solenoid at intake
manifold plenum. Install a "T" fitting between vacuum hose and intake
manifold plenum. Connect hand-held pressure/vacuum pump to "T"
fitting. Go to next step.
CAUTION: DO NOT apply more than 0.57 psi in following step. Applying
more than specified psi can crack fuel tank.
NOTE: Ensure fuel tank is at least 1/4 full. The lower the fuel
level in fuel tank, the longer it takes to pressurize fuel
system.
9) Using scan tool, read Fuel Tank Differential Pressure
(FTDP) sensor (item 73). Using hand-held pressure/vacuum pump, apply\
0.42 psi. If scan tool reading reaches 0.42 psi, replace fuel cap. Go
to step 20). If reading does not reach 0.42 psi, go to next step.
10) Disconnect hand-held pressure/vacuum pump from "T"
fitting. Install an evaporative emission system tester in place of
vacuum held pump and apply 0.49 psi. Wait two minutes. If pressure
drops less than 0.20 psi, go to next step. If pressure drops 0.29 psi
or more, go to step 13).
11) Disconnect EVAP purge solenoid-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, check EVAP purge
solenoid for leak. If EVAP purge solenoid is okay, replace hose. Go to
step 24). If pressure is maintained, go to next step.
12) Disconnect EVAP vent solenoid-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, check EVAP vent solenoid
for leak. If EVAP vent solenoid is okay, replace hose. Go to step 20).
If pressure is maintained, replace EVAP canister. Go to step 24).
13) Ensure hoses are properly routed and connected. See M -

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, replace solenoid. If solenoid tests as specified, go to
next step.
4) Ensure solenoid holds vacuum with nipple "B" unplugged,
and negative jumper wire disconnected. 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 next step.
6) Remove turbocharger by-pass valve. Connect vacuum pump to
by-pass valve nipple. Apply 16 in. Hg of vacuum. Ensure vacuum holds
and valve begins to open. If by-pass valve does not test as specified,
replace by-pass valve. If by-pass valve tests as specified, go to step
8).
7) Turn ignition switch to ON position. Using scan tool, turn
turbocharger wastegate solenoid on and off (item 12). Clicking sound
should be heard. If clicking sound is not heard, go to next step. If
clicking sound is heard, go to step 10).
8) Disconnect solenoid connector. Turn ignition switch to ON
position. Using DVOM, check for voltage between chassis ground and
solenoid connector terminal No. 1. If battery voltage does not exist,
repair wiring harness as necessary. If battery voltage exists, go to
next step.
9) Turn ignition switch to OFF position. Disconnect PCM
connector. Ground PCM connector terminal No. 41. Check continuity
between chassis ground and solenoid connector terminal No. 2. If
continuity does not exist, repair wiring harness as necessary. If
continuity exists, 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 P1105: FUEL PRESSURE SOLENOID FAILURE
NOTE: This test applies to 3000GT turbo 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 6). Remove vacuum hoses
from fuel pressure solenoid. Disconnect solenoid harness connector.
Connect a vacuum pump to solenoid nipple "A". See Fig. 47. Apply
vacuum and go to next step.
2) Using jumper wires, connect battery voltage and ground to
solenoid terminals. Ensure solenoid does not hold vacuum with nipple
"B" unplugged, and negative jumper wire disconnected. If solenoid does
not test as specified, replace solenoid. If solenoid tests as
specified, go to next step.
Fig. 47: Testing Fuel Pressure Solenoid
Courtesy of Mitsubishi Motor Sales of America
3) Ensure solenoid holds vacuum with nipple "B" plugged, and
negative jumper wire disconnected. If solenoid does not test as

* 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.

Brake On/Off (BOO) Switch ................... Cruise Control Systems\
Engine Performance
Shift Interlock Systems
Buzzer Module ...................................... Warning Systems
Camshaft Position (CMP) Sensor .................. Engine Performance\
Central Control Module ........................... Anti-Theft System
Clockspring ............................... Air Bag Restraint System
Cruise Control Systems
Steering Column Switches
Clutch Pedal Position Switch .............................. Starters
Clutch Start Switch ....................................... Starters
Combination Meter ......................... Analog Instrument Panels
Constant Control Relay Module (CCRM) ............ Engine Performance\
Electric Cooling Fans
Convenience Center .............................. Power Distribution
Illumination/Interior Lights
Convertible Top Motor ........................ Power Convertible Top
Convertible Top Switch ....................... Power Convertible Top
Crankshaft Position (CKP) Sensor ................ Engine Performance\
Cruise Control Module ....................... Cruise Control Systems
Cruise Control Switch ....................... Cruise Control Systems
Condenser Fan Relay(s) ....................... Electric Cooling Fans\
Data Link Connector (DLC) ....................... Engine Performance\
Daytime Running Lights Module ............... Daytime Running Lights
Exterior Lights
Defogger Relay ................................ Rear Window Defogger
Diagnostic Energy Reserve Module (DERM) ... Air Bag Restraint System\
Discriminating Sensor (Air Bag) ........... Air Bag Restraint System\
Distributor ..................................... Engine Performance
Door Lock Actuators ............................... Power Door Locks
Remote Keyless Entry
Door Lock Relay(s) ................................ Power Door Locks\
Electrochromic Mirror ................................ Power Mirrors
Electronic Level Control (ELC)
Height Sensor .............................. Electronic Suspension
Electronic Level Control (ELC) Module ........ Electronic Suspension\
Engine Coolant Temperature (ECT)
Sending Unit ............................ Analog Instrument Panels
Engine Coolant Temperature (ECT) Sensor ......... Engine Performance\
Engine Control Module ........................... Engine Performance
Generators & Regulators
Starters
ETACS ECU .......................................... Warning Systems
Power Windows
Remote Keyless Entry
Evaporative (EVAP) Emissions Canister ........... Engine Performance\
EVAP Canister Purge Solenoid .................... Engine Performance
EVAP Canister Vent Solenoid ..................... Engine Performance
Exhaust Gas Recirculation (EGR) Valve ........... Engine Performance\
Fuel Tank Vacuum Sensor ......................... Engine Performance
Fog Lights ....................................... Headlight Systems
Daytime Running Lights
Fog Light Relay .................................. Headlight Systems
Daytime Running Lights
Fuel Door Release Solenoid ................. Power Fuel Door Release
Fuel Gauge Sending Unit ................... Analog Instrument Panels
Fuel Injectors .................................. Engine Performance
Fuel Pump ....................................... Engine Performance
Fuel Pump Relay ................................. Engine Performance
Power Distribution
Fuse/Relay Block ................................ Power Distribution
Fusible Links ................................... Power Distribution
Generators & Regulators

Torque Converter Clutch Solenoid/Switch ......... Engine Performance
Traction Control Switch ........................... Anti-Lock Brakes
Trailer Tow Connector .............................. Exterior Lights
Trailer Tow Relay .................................. Exterior Lights
Transmission/Transaxle .......................... Engine Performance
Transmission Control Module (TCM) ............... Engine Performance\
Starters
Transmission Range Sensor ................................. Starters
Back-Up Lights
Engine Performance
Transmission Range Switch ........................... Back-Up Lights
Engine Performance
Anti-Theft System
Turn Signal Flasher ................................ Exterior Lights
Turn Signal Lights ................................. Exterior Lights
Twilight Sentinel Switch ......................... Headlight Systems
Daytime Running Lights
Vapor Canister Leak Detection Pump .............. Engine Performance
Vehicle Control Module (VCM) .................... Engine Performance\
Vehicle Dynamic Module ....................... Electronic Suspension
Vehicle Speed Control Servo ................. Cruise Control Systems
Vehicle Speed Sensor .......................... Data Link Connectors
Analog Instrument Panels
Cruise Control Systems
Electronic Suspension
Voltage Regulator .......................... Generators & Regulators
Water-In-Fuel Sensor ............................ Engine Performance
Analog Instrument Panels
Wheel Speed Sensors ............................... Anti-Lock Brakes
Window Timer Module .......................... Power Convertible Top
Windshield Intermittent Wiper Relay ........... Wiper/Washer Systems
Windshield Washer Motor ....................... Wiper/Washer Systems
Wiper Motor ................................... Wiper/Washer Systems









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THROTTLE POSITION (TP) SWITCH or THROTTLE POSITION (TP) SENSOR in G \
-
TESTS W/CODES article.
Engine Coolant Temperature Sensor
See G - TESTS W/CODES article.
Heated Oxygen Sensor
See G - TESTS W/CODES article.
Intake Air Temperature (IAT) Sensor
On all models except Eclipse 2.0L non-turbo and Mirage 1.5L,
IAT sensor is a part of volume airflow sensor assembly. On all models,
see G - TESTS W/CODES article.
Manifold Absolute Pressure Sensor
See G - TESTS W/CODES article.
Manifold Differential Pressure Sensor
See G - TESTS W/CODES article.
Power Steering Oil Pressure (PSP) Switch
On Eclipse 2.0L non-turbo, see DTC 115 in G - TESTS W/CODES -
NON-TURBO article. On all other models except Eclipse 2.0L non-turbo,
see G - TESTS W/CODES article.
Throttle Position Sensor
See G - TESTS W/CODES article.
Vehicle Speed Sensor
See G - TESTS W/CODES article.
Volume Airflow Sensor
See G - TESTS W/CODES article.
MOTORS, RELAYS & SOLENOIDS
MOTORS
Idle Air Control Motor
See G - TESTS W/CODES article.
RELAYS
ASD, Fuel Pump & MFI Relay
See G - TESTS W/CODES article.
Radiator Cooling Fan Control Relay (High & Low)
See G - TESTS W/CODES article.
SOLENOIDS
EGR Control Solenoid Valve
See EXHAUST GAS RECIRCULATION (EGR) under EMISSION SYSTEMS &
SUB-SYSTEMS.
EVAP Purge Control Solenoid Valve
See FUEL EVAPORATION under EMISSION SYSTEMS & SUB-SYSTEMS.
Fuel Pressure Regulator Control Solenoid Valve (Turbo Models)
See FUEL DELIVERY under FUEL SYSTEM.
Wastegate Control Solenoid Valve

DISTRIBUTOR
NOTE: Eclipse, Mirage 1.8L, Montero, Montero Sport 3.0L and 3000GT
DOHC use Distributorless Ignition System (DIS). All other
models use distributor type ignition systems with
non-serviceable distributors on which only the rotor and
distributor cap can be changed.
FUEL SYSTEM
* PLEASE READ THIS FIRST *
WARNING: Always relieve fuel pressure before disconnecting any fuel
injection-related component. DO NOT allow fuel to contact
engine or electrical components.
FUEL SYSTEM PRESSURE RELEASE
Relieving Fuel Pressure
1) On Diamante, disconnect fuel pump harness connector at
fuel tank from underneath vehicle. On Montero and Montero Sport,
remove cargo compartment carpet, remove access plate and disconnect
fuel pump harness connector. On all other models, remove rear seat
cushion and remove access plate (if required) to disconnect fuel pump
harness connector.
2) On all models, start engine. Let engine run until it
stops. Turn ignition off. Disconnect negative battery cable. Connect
fuel pump harness connector. Reinstall rear seat (if necessary.)
FUEL PUMP
Removal & Installation (Diamante, Eclipse, Galant & Montero)
1) Fuel pump assembly is located inside fuel tank. Release
fuel pressure. See FUEL SYSTEM PRESSURE RELEASE . Remove access panel
under seat, in trunk or in rear cargo area. Disconnect electrical
connectors and fuel hoses at fuel tank.
2) Remove fuel filler hose from fuel tank. Remove fuel pump
assembly. To install, reverse removal procedure. Tighten nuts to
specification. See TORQUE SPECIFICATIONS .
Removal & Installation (Mirage, Montero Sport & 3000GT)
1) Fuel pump assembly is located inside fuel tank. Release
fuel pressure. See FUEL SYSTEM PRESSURE RELEASE . Raise vehicle on
hoist. Drain fuel into suitable container. Disconnect electrical
connectors and breather/fuel hoses at fuel tank.
2) Remove fuel filler hose from fuel tank. Support fuel tank
with transmission jack. Remove nuts securing fuel tank. Remove fuel
tank from vehicle. Remove fuel pump assembly. To install, reverse
removal procedure. Tighten nuts to specification. See
TORQUE SPECIFICATIONS .
FUEL RAILS & INJECTORS
WARNING: Use a rag to cover fuel hose connection before disconnecting
high pressure fuel hose at fuel rail. Some residual fuel
pressure may still be in system.
CAUTION: DO NOT drop injectors while removing or installing fuel rail.
Removal (Diamante, Montero Sport 2.4L & 3000GT)