power steering MITSUBISHI MONTERO 1998 User Guide
[x] Cancel search | Manufacturer: MITSUBISHI, Model Year: 1998, Model line: MONTERO, Model: MITSUBISHI MONTERO 1998Pages: 1501, PDF Size: 25.81 MB
Page 457 of 1501

HO2S detects oxygen content in exhaust gas and sends this
information to PCM. PCM uses input signals from HO2S to vary duration
of fuel injection. HO2S heater stabilizes sensor temperature
regardless of exhaust gas temperature to allow for more accurate
exhaust oxygen content readings.
Idle Air Control (IAC) Valve Position Sensor
Sensor is incorporated in IAC motor. Sensor senses IAC motor
plunger position and sends electrical signal to PCM.
Ignition Timing Adjustment Terminal
Used for adjusting base ignition timing. When terminal is
grounded, PCM timing control function is by-passed, allowing base
timing to be adjusted.
Intake Air Temperature (IAT) Sensor
IAT sensor is incorporated into airflow sensor assembly. This
resistor-based sensor measures temperature of incoming air and
supplies air density information to PCM.
Knock Sensor (KS)
KS is located in cylinder block and senses engine vibration
during detonation (knock). KS converts vibration into electrical
signal. PCM retards ignition timing based on this signal.
Manifold Differential Pressure (MDP) Sensor
MDP sensor converts negative air pressure in intake manifold
plenum into voltage signals sent to PCM. PCM monitors Exhaust Gas
Recirculation (EGR) system using these signals.
Park/Neutral Position (PNP) Switch (Automatic Transmission)
PNP switch senses position of transmission select lever,
indicating engine load due to automatic transmission engagement. Based
on this signal, PCM commands IAC motor to increase throttle angle,
maintaining optimum idle speed.
Power Steering Oil Pressure Switch
Switch detects increase in power steering oil pressure. When
power steering oil pressure increases, switch contacts close,
signaling PCM. PCM commands IAC motor, raising idle speed to
compensate for drop in engine RPM due to power steering load.
Throttle Position (TP) Sensor
TP sensor is a variable resistor mounted on throttle body.
PCM uses voltage signal from TP sensor to determine throttle plate
angle.
Vehicle Speed Sensor (VSS)
Mounted on transaxle/transmission, VSS sends a pulsing signal
to PCM for vehicle speed calculation. PCM uses this calculation for
cruise control and fuel cut-off.
Volume Airflow (VAF) Sensor
Incorporated into airflow sensor assembly, VAF sensor
measures intake airflow rate. Intake air flows through tunnel in
airflow sensor assembly. VAF sensor sends frequency signal to PCM. PCM
uses signal to adjust fuel injection rate.
OUTPUT SIGNALS
NOTE: Vehicles are equipped with various combinations of
computer-controlled components. Not all components listed
below are used on every vehicle. To determine component
Page 459 of 1501

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
Page 466 of 1501

Headlight Relay In engine compartment
relay box.
Headlight Washer Relay On bracket, behind left side
of dash.
Horn Relay Left front of engine
compartment.
Ignition Key Hole Illumination Light
Timer Behind center console.
Intermittent Wiper Relay (Rear Wiper) In passenger compartment
relay box.
Intermittent Wiper Relay (Windshield
Wiper) Built-in to steering column
switch.
Power Window Relay In passenger compartment
relay box.
Starter Relay Behind center console.
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Center Differential Lock Operation
Detection Switch On transfer case.
Dual Pressure Switch On high pressure line, on
receiver-drier.
Engine Coolant Temperature Switch Top right front of engine.
Free Wheel Engage Switch Right side of engine
compartment.
High Range/Low Range Detection Switch On transfer case.
Low Range Operation Detection Switch On transfer case.
Oil Pressure Switch Lower left front of engine.
Parking Brake Switch At base of parking brake
lever.
Power Steering Pressure Switch On power steering pump.
Rear Differential Lock Detection
Switch Under rear of vehicle, on
differential.
Reed Switch Integral with speedometer.
Seat Belt Switch On driver-side seat belt
buckle.
Stoplight Switch On bracket, above brake pedal.
2WD/4WD Detection Switch On transfer case.
4WD Operation Detection Switch On transfer case.
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MISCELLANEOUS
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Component Component Location \
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Amplifier Under center console, below
floor.
Data Link Connector (DLC) Behind left side of dash,
near relay box.
Page 590 of 1501

FUEL TANKS
GAS CAPS
GASKETS
GROMMETS (VALVE COVER)
HARMONIC DAMPERS
HEATER CONTROL VALVES
HEATER CORES
HOSE AND TUBE COUPLERS, CONNECTORS AND CLAMPS
HOSE CLAMPS
HOSE CONNECTORS
HOSE COUPLERS
HOSES AND TUBES (FUEL LINES, RADIATOR, VACUUM, BY PASS,
HEATER, RECOVERY TANK AND OIL COOLERS)
HOUSINGS
IDLE AIR CONTROLS
IDLE SPEED CONTROL ACTUATORS
IGNITION BOOTS
IGNITION COIL TOWERS
IGNITION COILS
IGNITION CONTROL MODULES (ICM)
IGNITION SWITCHES
IGNITION TERMINALS
IGNITION WIRES, BOOTS, COIL TOWERS AND TERMINALS (SECONDARY)
IN-TANK FUEL STRAINERS
INERTIA FUEL SHUT-OFF SWITCHES
INTAKE AIR TEMPERATURE SENSORS
INTAKE MANIFOLDS
INTERCOOLERS
KNOCK SENSORS
LIQUID VAPOR SEPARATORS
MANIFOLD ABSOLUTE PRESSURE (MAP) SENSORS
MASS AIR FLOW (MAF) SENSORS
METAL AIR MANIFOLDS AND PIPES
METAL AIR PIPES
MIX CONTROL SOLENOIDS
MOTOR MOUNTS
O-RINGS, GASKETS, SEALS AND SPRING LOCKS
O2 SENSORS
OIL PRESSURE SENDING UNITS
OIL PUMP PICK-UP SCREENS
OIL PUMPS
PARK NEUTRAL POSITION SWITCHES
PCV BREATHER ELEMENTS
PCV ORIFICES
PCV VALVES
PICK-UP ASSEMBLIES (INCLUDES MAGNETIC, HALL EFFECT AND
OPTICAL)
POWER STEERING PRESSURE SENSORS
POWERTRAIN CONTROL MODULES (PCM) AND PROM
POWERTRAIN CONTROL PROM
PRESSURIZED EXPANSION TANK CAPS
RADIATOR CAPS AND PRESSURIZED EXPANSION TANK CAPS
RADIATOR FAN BLADES
RADIATOR FAN CLUTCHES
RADIATORS
ROLL OVER VALVES
SEALING COMPOUNDS
SEALS
SECONDARY AIR INJECTION SYSTEM MANAGEMENT DEVICES
SENSORS AND ACTUATORS
SHROUDS, BAFFLES AND DEFLECTORS
SPARK PLUGS
SPRING LOCKS
Page 667 of 1501

Terminal broken ......... A .. Require repair or replacement.
Terminal burned, affecting
performance ............ A ........... (1) Require repair or
replacement.
Terminal burned, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal corroded,
affecting performance .. A .. Require repair or replacement.
Terminal corroded, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal loose, affecting
performance ............ B .. Require repair or replacement.
Terminal loose, not
affecting performance .. 1 .. Suggest repair or replacement.
Wire lead conductors
exposed ................ B .. Require repair or replacement.
Wire lead corroded ...... A .. Require repair or replacement.
Wire lead open .......... A .. Require repair or replacement.
Wire lead shorted ....... A .. Require repair or replacement.
( 1) - Determine cause and correct prior to repair or
replacement of part.
( 2) - Inoperative includes intermittent operation or out of
OEM specification. Refer to OEM recommended service'
procedures.
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POWER STEERING PRESSURE SENSORS
POWER STEERING PRESSURE SENSOR INSPECTION \
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Condition Code Procedure
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware
threads damaged ........ A ... Require repair or replacement
of hardware.
Attaching hardware
threads stripped
(threads missing) ...... A ... Require repair or replacement
of hardware.
Connector broken ........ A .. Require repair or replacement.
Connector (Weatherpack
type) leaking .......... A .. Require repair or replacement.
Connector melted ........ A ........... ( 1) Require repair or
replacement.
Connector missing ....... C ............ Require replacement.
Contaminated ............ A ........... ( 2) Require repair or
replacement.
Inoperative ............. B ........... ( 3) Require repair or
replacement. Further
inspection required.
Leaking ................. A .. Require repair or replacement.
Missing ................. C ............ Require replacement.
Resistance out of
specification .......... B .. Require repair or replacement.
Restricted, affecting
performance ............ A .. Require repair or replacement.
Terminal broken ......... A .. Require repair or replacement.
Terminal burned, affecting
performance ............ A ........... ( 1) Require repair or
Page 673 of 1501

Wire lead open .......... A .. Require repair or replacement.
Wire lead shorted ....... A .. Require repair or replacement.
(1) - Determine cause and correct prior to repair or
replacement of part.
( 2) - Determine source of contamination, such as engine coolant,
fuel, metal particles, or water. Require repair or
replacement.
( 3) - Inoperative includes intermittent operation or out of
OEM specification. Some components may be serviceable;
check for accepted cleaning procedure.
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SENSORS AND ACTUATORS
NOTE: Conditions pertaining to the sensors and actuators listed
in this section may be found under the name of the sensor
or actuator.
SENSOR ABBREVIATION TABLE
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Sensor Abbreviation
Accelerator Pedal Position Sensor ......................... APP
Air Conditioning Cycling Switch ............................ AC
Air Conditioning Pressure Sensor ........................... ..
Air Fuel Ratio Sensor ...................................... ..
Barometric Pressure Sensor ............................... BARO
Camshaft Position Sensor .................................. CMP
Clutch Pedal Position Switch .............................. CPP
Cooling Fan Motor Sensors and Switches ..................... ..
Crankshaft Position Sensor ................................ CKP
Electronic Transmission Feedback Devices ................... ..
Engine Coolant Temperature Sensor ......................... ECT
Evaporative Emission feedback devices ...................... ..
Exhaust Gas Recirculation feedback devices ................. ..
Fan Control Sensor ......................................... FC
Intake Air Temperature Sensor ............................. IAT
Knock Sensor ............................................... KS
Manifold Absolute Pressure Sensor ......................... MAP
Mass Air Flow Sensor ...................................... MAF
O2 Sensor ................................................. O2S
Park Neutral Position Switch .............................. PNP
Power Steering Pressure Sensor ............................ PSP
Thermal Vacuum Valve ...................................... TVV
Throttle Position Sensor ............................ TP Sensor
Throttle Position Switch ................................... ..
Transmission Range Switch ........................... TR Switch
Vehicle Speed Sensor ...................................... VSS
Volume Air Flow Sensor .................................... VAF
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ACTUATOR ABBREVIATION TABLE \
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Actuator Abbreviation
Air Injection Control Solenoid ............................. ..
Electronic Transmission control devices .................... ..
Evaporative Emission Canister ............................ EVAP
Purge Device ............................................... ..
Exhaust Gas Recirculation Device .......................... EGR
Fuel Injector .............................................. ..
Idle Air Control .......................................... IAC
Page 723 of 1501

purge control valve, or vacuum hose routing.
DTC P0443
Evaporative (EVAP) purge control valve circuit failure.
Possible causes are: connector or harness, or faulty EVAP solenoid.
DTC P0446
Evaporative (EVAP) emission control system vent control
failure. Possible causes are: connector or harness, faulty EVAP vent
solenoid.
DTC P0450
Evaporative (EVAP) emission control system pressure sensor
failure. Possible causes are: connector or harness, or faulty fuel
tank differential pressure sensor.
DTC P0455
Evaporative (EVAP) emission control system large leak
detected. Possible causes are: connector or harness, faulty EVAP purge
solenoid, purge control valve, or vacuum hose routing.
DTC P0500
Vehicle Speed Sensor (VSS) failure. Possible causes are:
connector or harness, or faulty VSS.
DTC P0505
Idle Air Control (IAC) system failure. Possible causes are:
connector or harness, or faulty IAC motor.
DTC P0510
Closed Throttle Position (TP) switch failure. Possible causes\
are: connector or harness, or faulty closed TP switch.
DTC P0551
Power Steering Pressure (PSP) sensor failure. Possible causes\
are: connector or harness, or faulty PSP sensor.
DTC P0705
Automatic transaxle/transmission range sensor circuit
failure. Possible causes are: connector or harness, or faulty PNP
switch.
DTC P0710
Automatic transaxle/transmission fluid sensor failure.
Possible causes are: connector or harness, or faulty
transaxle/transmission sensor.
DTC P0715
Automatic transaxle input/turbine speed sensor circuit
failure. Possible causes are: connector or harness, or pulse
generator.
DTC P0720
Automatic transaxle input/turbine speed sensor circuit
failure. Possible causes are: connector or harness, or pulse
generator.
DTC P0725
Engine speed input circuit failure. Possible causes are:
connector or harness.
DTC P0740
Torque converter clutch system failure. Possible causes are:
Page 761 of 1501

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.
7) 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.
8) Using scan tool, read Power Steering Pressure (PSP) switc\
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status (item 27). Switch status should read ON when steering wheel is
turned. If switch status is as specified, go to step 24). If switch
status is not as specified, go to DTC P0551 test.
9) 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.
10) 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 24). If reading does not reach 0.42 psi, go to next step.
11) 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 14).
12) 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.
13) 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 24).
If pressure is maintained, replace EVAP canister. Go to step 24).
14) Ensure hoses are properly routed and connected. See M -
VACUUM DIAGRAMS article. Install hoses as necessary and go to step
24). If hoses are okay, go to next step.
15) 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 24). If pressure is maintained,
go to next step.
16) 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 20).
17) 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 19).
18) Disconnect EVAP purge solenoid-to-EVAP canister hose at
Page 765 of 1501

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 -