sensor MITSUBISHI TRITON 1997 Workshop Manual

GENERAL ± Supplemental Restraint System (SRS)00-31
Harness connector
(No. of terminals,
colour)SDU
terminal
No.Destination of harnessCorrective action
2 pins, red1, 2Body wiring harness
Clock springReplace clock spring
±3, 4±±
±5, 6±±
14 pins, red7, 8±±
9Body wiring harness
Diagnosis connectorCorrect or replace each
wiring harness
10Body wiring harness
Front wiring harness

Ignition switch (ST)
wiring harness
11Body wiring harness
Junction block (fuse No. 11)
12Body wiring harness
Junction block (fuse No. 10)
13Body wiring harness
Combination meter (SRS
warning lamp)
14±±
15Body wiring harness
Front wiring harness

Front impact sensor (+) (R.H.)Sensor cable* installa-
tion procedures
(Refer to GROUP 52B )16Body wiring harness
Front wiring harness

Front impact sensor (+) (L.H.)(Refer to GROUP 52B.)
17Body wiring harness
Front wiring harness

Front impact sensor (±) (L.H.)
18Body wiring harness
Front wiring harness

Front impact sensor (±) (R.H.)
19, 20Body wiring harness
EarthCorrect or replace each
wiring harness
NOTE
The sensor cable marked with * is available as service part.
7. SRS components should not be subjected to heat over 93
C, so remove the SRS-diagnosis unit,
air bag module, clock spring and front impact sensors before drying or braking the vehicle after painting.
8. Whenever you finish servicing the SRS, check warning lamp operation to make sure that the system
functions properly. (Refer to GROUP 52B ± SRS Maintenance.)
9. Make certain that the ignition switch is OFF when the MUT-II is connected or disconnected.
10. If you have any questions about the SRS, please contact your local distributor.
NOTE
SERIOUS INJURY CAN RESULT FROM UNINTENDED AIR BAG DEPLOYMENT, SO USE ONLY
THE PROCEDURES AND EQUIPMENT SPECIFIED IN THIS MANUAL.

ENGINE <4G6> ± On-vehicle Service11A-11
16. Attach a sealing tape to the fixing bolt and nut only for
vehicles for Switzerland.
NOTE
Sealing tape is attached to all new vehicles.
IDLE SPEED CHECK11100190330
1. Before inspection, set the vehicle to the pre-inspection
condition.
2. Check the basic ignition timing. Adjust if necessary.
Standard value: 5 BTDC+2
3. After turning the ignition switch to OFF, connect the MUT-II
to the diagnosis connector.
4. Start the engine and run it at idle.
5. Run the engine at idle for 2 minutes.
6. Check the idle speed.
Curb idle speed: 750+100 r/min
NOTE
The idle speed is controlled automatically by the idle speed
control (ISC) system.
7. If the idle speed is outside the standard value, inspect
the MPI components by referring to GROUP 13A ±
Troubleshooting.
IDLE MIXTURE CHECK11100210265
1. Before inspection, set the vehicle to the pre-inspection
condition.
2. Check that the basic ignition timing is within the standard
value.
Standard value: 5 BTDC+2
3. Turn the ignition switch to OFF and connect the MUT-II
to the diagnosis connector.
4. Start the engine and run it at 2,500 r/min for 2 minutes.
5. Set the CO, HC tester.
6. Check the CO contents and the HC contents at idle.
Standard value:
CO contents: 0.5% or less
HC contents: 100 ppm or less
7. If there is a deviation from the standard value, check
the following items:

Diagnosis output

Closed-loop control (When the closed-loop control
is normal, the output signal of the oxygen sensor
changes between 0 ± 400 mV and 600 ± 1,000 mV
at idle.)

MPI ± General Information13A-3
MULTIPOINT FUEL INJECTION (MPI)13100010265
GENERAL INFORMATION
The Multipoint Fuel Injection System consists
of sensors which detect the engine conditions,
the engine-ECU which controls the system
based on signals from these sensors, and
actuators which operate under the control of
the engine-ECU. The engine-ECU carries outactivities such as fuel injection control, idle
speed control and ignition timing control. In
addition, the engine-ECU is equipped with
several diagnosis modes which simplify
troubleshooting when a problem develops.
FUEL INJECTION CONTROL
The injector drive times and injector timing are
controlled so that the optimum air/fuel mixture
is supplied to the engine to correspond to the
continually-changing engine operation condi-
tions.
A single injector is mounted at the intake port
of each cylinder. Fuel is sent under pressure
from the fuel tank by the fuel pump, with the
pressure being regulated by the fuel pressure
regulator. The fuel thus regulated is distributed
to each of the injectors.
Fuel injection is normally carried out once for
each 2-cylinder group for every two rotationsof the crankshaft. This is called group fuel
injection. The engine-ECU provides a richer
air/fuel mixture by carrying out ªopen-loopº
control when the engine is cold or operating
under high load conditions in order to maintain
engine performance. In addition, when the
engine is warm or operating under normal
conditions, the engine-ECU controls the air/fuel
mixture by using the oxygen sensor signal to
carry out ªclosed-loopº control in order to obtain
the theoretical air/fuel mixture ratio that
provides the maximum cleaning performance
from the three way catalyst.
IDLE AIR CONTROL
The idle speed is kept at the optimum speed
by controlling the amount of air that bypasses
the throttle valve in accordance with changes
in idling conditions and engine load during
idling. The engine-ECU drives the idle speed
control (ISC) motor to keep the engine running
at the pre-set idle target speed in accordance
with the engine coolant temperature and airconditioner load. In addition, when the air
conditioner switch is turned off and on while
the engine is idling, the ISC motor operates
to adjust the throttle valve bypass air amount
in accordance with the engine load conditions
in order to avoid fluctuations in the engine
speed.
IGNITION TIMING CONTROL
The power transistor located in the ignition
primary circuit turns ON and OFF to control
the primary current flow to the ignition coil. This
controls the ignition timing in order to provide
the optimum ignition timing with respect to theengine operating conditions. The ignition timing
is determined by the engine-ECU from the
engine speed, intake air volume, engine coolant
temperature and atmospheric pressure.
SELF-DIAGNOSIS FUNCTION

When an abnormality is detected in one
of the sensors or actuators related to
emission control, the engine warning lamp
(check engine lamp) illuminates as a
warning to the driver.

When an abnormality is detected in one
of the sensors or actuators, a diagnosiscode corresponding to the abnormality is
output.

The RAM data inside the ENGINE-ECU
that is related to the sensors and actuators
can be read by means of the MUT-II. In
addition, the actuators can be force-driven
under certain circumstances.

MPI ± General Information13A-4
OTHER CONTROL FUNCTIONS
1. Fuel Pump Control
Turns the fuel pump relay ON so that current
is supplied to the fuel pump while the engine
is cranking or running.
2. A/C Relay Control
Turns the compressor clutch of the A/C
ON and OFF.3. Purge Control Solenoid Valve Control
Refer to GROUP 17.
4. EGR Control Solenoid Valve Control
Refer to GROUP 17.
GENERAL SPECIFICATIONS
ItemsSpecifications
Throttle bodyThrottle bore mm54
Throttle position sensorVariable resistor type
Idle speed control servoStepper motor type
(Stepper motor type by-pass air control system with the air
volume limiter)
Idle position switchRotary contact type, within throttle position sensor
Engine-ECUIdentification model No.E2T64271 <4G63 - Vehicles without immobilizer system>
E2T64277 <4G63 - Vehicles with immobilizer system>
E2T64272 <4G64 - Vehicles without immobilizer system>
E2T64276 <4G64 - Vehicles with immobilizer system>
SensorsAir flow sensorKarman vortex type
Barometric pressure sensorSemiconductor type
Intake air temperature sensorThermistor type
Engine coolant temperature sensorThermistor type
Oxygen sensorZirconia type
Vehicle speed sensorMagnetic resistive element type
Top dead centre sensorHall element type
Crank angle sensorHall element type
Power steering fluid pressure switchContact switch type
ActuatorsControl relay typeContact switch type
Fuel pump relay typeContact switch type
Injector type and numberElectromagnetic type, 4
Injector identification markCDH275
EGR control solenoid valveDuty cycle type solenoid valve
Purge control solenoid valveON/OFF type solenoid valve
Fuel pressure
regulatorRegulator pressure kPa328

MPI ± Service Specifications/Sealant13A-6
SERVICE SPECIFICATIONS13100030216
ItemsSpecifications
Basic idle speed r/min750+50
Idle speed when A/C is ON r/min900 at neutral position
Throttle position sensor adjusting voltage mV400 ± 1,000
Throttle position sensor resistance kW3.5 ± 6.5
Idle speed control servo coil resistance W28 ± 33 (at 20
C)
Intake air temperature sensor
resistance kW
20
C2.3 ± 3.0
resistance kW
80
C0.30 ± 0.42
Engine coolant temperature
sensor resistance kW
20
C2.1 ± 2.7
sensor resistance kW
80
C0.26 ± 0.36
Oxygen sensor output voltage V0.6 ± 1.0
Fuel pressure kPaVacuum hose disconnection324 ± 343 at curb idle
Vacuum hose connectionApprox. 265 at curb idle
Injector coil resistance W13 ± 16 (at 20
C)
SEALANT13100050038
ItemSpecified sealantRemark
Engine coolant temperature sensor
threaded portion3M Nut Locking Part No. 4171 or equivalentDrying sealant

MPI ± Troubleshooting13A-9
Engine warning lamp inspection items
Engine-ECU
Oxygen sensor
Air flow sensor
Intake air temperature sensor
Throttle position sensor
Engine coolant temperature sensor
Crank angle sensor
Top dead centre sensor
Barometric pressure sensor
Ignition timing adjustment signal
Injector
Immobilizer system
Caution
Engine warning lamp will come on even when terminal
for ignition timing adjustment is short-circuited.
Therefore, it is not abnormal that the lamp comes
on even when terminal for ignition timing adjustment
is short-circuited at the time of ignition timing
adjustment.
METHOD OF READING AND ERASING DIAGNOSIS
CODES
Refer to GROUP 00 ± How to Use Troubleshooting/Inspection
Service Points.
INSPECTION USING MUT-II DATA LIST AND
ACTUATOR TESTING
1. Carry out inspection by means of the data list and the
actuator test function.
If there is an abnormality, check and repair the chassis
harnesses and components.
2. After repairing, re-check using the MUT-II and check that
the abnormal input and output have returned to normal
as a result of the repairs.
3. Erase the diagnosis code memory.
4. Remove the MUT-II.
5. Start the engine again and carry out a road test to confirm
that the problem has disappeared.

MPI ± Troubleshooting13A-10
FAIL-SAFE FUNCTION REFERENCE TABLE13100910190
When the main sensor malfunctions are detected by the diagnosis function, the vehicle is controlled
by means of the pre-set control logic to maintain safe conditions for driving.
Malfunctioning itemControl contents during malfunction
Air flow sensor1. Uses the throttle position sensor signal and engine speed signal (crank angle sensor
signal) to take reading of the basic injector drive time and basic ignition timing from
the pre-set mapping.
2. Fixes the ISC servo in the appointed position so idle control is not performed.
Intake air temperature
sensorControls as if the intake air temperature is 25
C.
Throttle position
sensor (TPS)No increase in fuel injection amount during acceleration due to the throttle position sensor
signal.
Engine coolant
temperature sensorControls as if the engine coolant temperature is 80
C.
Top dead centre
sensorInjects fuel to all cylinders simultaneously.
(However, after the ignition switch is turned to ON, the No. 1 cylinder top dead centre is not
detected at all.)
Barometric pressure
sensorControls as if the barometric pressure is 101 kPa.
Oxygen sensorAir/fuel ratio feedback control (closed loop control) is not performed.
INSPECTION CHART FOR DIAGNOSIS CODES13100870214
Code No.Diagnosis itemReference page
11Oxygen sensor system13A-11
12Air flow sensor system13A-12
13Intake air temperature sensor system13A-12
14Throttle position sensor system13A-13
21Engine coolant temperature sensor system13A-14
22Crank angle sensor system13A-15
23Top dead centre sensor system13A-16
24Vehicle speed sensor system13A-17
25Barometric pressure sensor system13A-18
36*Ignition timing adjustment signal system13A-19
41Injector system13A-19
54Immobilizer system13A-20
NOTE
*: Malfunction code No. 36 is not memorized.

MPI ± Troubleshooting13A-11
INSPECTION PROCEDURE FOR DIAGNOSIS CODES
Code No. 11 Oxygen sensor systemProbable cause
Range of Check

3 minutes have passed after engine was started.

Engine coolant temperature is approx. 80C or more.

Intake air temperature is 20 ± 50C.

Engine speed is approx. 2,000 ± 3,000 r/min

Vehicle is moving at constant speed on a flat, level road surface
Set conditions

The oxygen sensor output voltage is around 0.6 V for 30 seconds (does not cross
0.6 V for 30 seconds).

When the range of check operations given above which accompany starting of
the engine are carried out four time in succession, a problem is detected after
each operation.
Malfunction of the oxygen sensor

Improper connector contact, open circuit or
short-circuited harness wire

Malfunction of the engine-ECU
Check the oxygen sensor. (Refer to P.13A-88.)NG
Replace
OK
Measure at the oxygen sensor connector B-03.

Disconnect the connector, and measure at the
harness side.
1. Voltage between 1 and earth (Ignition switch: ON)
OK:System voltage
2. Continuity between 2 and earth
OK:Continuity
OK1. NG
Check the harness wire between the
oxygen sensor and the control relay
connector, and repair if necessary.
2. NG
Check the following connector.
C-51, C-60NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire between the
engine-ECU and the oxygen sensor
connector.NG
Repair
OK
Replace the engine-ECU.
Measure at the engine-ECU connector C-50.

Disconnect the connector, and measure at the
harness side.

Voltage between 35 and earth (Ignition switch: ON)
OK:System voltage
NGCheck the following connector.
B-03, C-60NG
Repair
OK
Check the following connectors.
B-03, C-50NG
RepairCheck trouble symptom.OK
OKNGCheck the harness wire between the
engine-ECU and the oxygen sensor
connector, and repair if necessary.
Check trouble symptom.
NG
Check the harness wire between the engine-ECU and
the oxygen sensor connector.NG
Repair
OK
Replace the engine-ECU.

MPI ± Troubleshooting13A-12
Code No. 12 Air flow sensor systemProbable cause
Range of Check

Engine speed is 500 r/min or more.
Set conditions

Sensor output frequency is 3 Hz or less for 4 seconds.
Malfunction of the air flow sensor

Improper connector contact, open circuit or
short-circuited harness wire of the air flow sensor

Malfunction of the engine-ECU
Measure at the air flow sensor con-
nector A-77.

Connect the connector. (Use
the test harness: MB991348)
1. Voltage between 3 and earth
(Engine: Idling)
OK:2.2 ± 3.2 V
2. Voltage between 7 and earth
OK:0 ± 1 V (Engine: idling)
6 ± 9 V (2,000 r/min)
OK
Replace the engine-ECU.1. NG
Check the air flow sensor circuit.
(Refer to P.13A-54, INSPECTION
PROCEDURE 45.)
2. NG
Measure at the engine-ECU con-
nector C-49.

Connect the connector.

Voltage between 19 and earth
(Ignition switch: ON)
OK:6±9 V
OK
Check the following connector.
C-49
OK
Check trouble symptom.
NG
Replace the engine-ECU.NG
Check the following connector.
A-77NG
Repair
OK
Check trouble symptom.
NG
NG
Repair
Replace the air flow sensor.
Code No. 13 Intake air temperature sensor systemProbable cause
Range of Check

Ignition switch: ON

Excluding 60 seconds after the ignition switch is turned to ON or immediately
after the engine starts.
Set conditions

Sensor output voltage is 4.6 V or more (corresponding to an intake air temperature
of ±45C or less) for 4 seconds.
or

Sensor output voltage is 0.2V or less (corresponding to an intake air temperature
of 125C or more) for 4 seconds.
Malfunction of the intake air temperature sensor

Improper connector contact, open circuit or
short-circuited harness wire of the intake air
temperature sensor circuit

Malfunction of the engine-ECU
Check the intake air temperature
sensor.
(Refer to P.13A-86.)NG
Replace
OK
Measure at the air flow sensor con-
nector A-77.

Disconnect the connector, and
measure at the harness side.

Voltage between 6 and earth
(Ignition switch: ON)
OK:4.5 ± 4.9 V

Continuity between 5 and earth
OK:ContinuityNGCheck the following connector.
C-51NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire between
the engine-ECU and the intake air
temperature sensor connector.NG
Repair
OK
Replace the engine-ECU. OK
Check the following connector.
A-77NG
Repair
OK
Check trouble symptom.NGReplace the engine-ECU.

MPI ± Troubleshooting13A-13
Code No. 14 Throttle position sensor systemProbable cause
Range of Check

Ignition switch: ON

Excluding 60 seconds after the ignition switch is turned to ON or immediately
after the engine starts.
Set conditions

When the idle position switch is ON, the sensor output voltage is 2 V or more
for 4 seconds.
or

The sensor output voltage is 0.2 V or less for 4 seconds.
Malfunction of the throttle position sensor or
maladjustment

Improper connector contact, open circuit or
short-circuited harness wire of the throttle position
sensor circuit

Improper ªONº state of idle position switch

Short circuit of the idle position switch signal line

Malfunction of the engine-ECU
MUT-II Data list
26 Idle position switch system
OK:With the throttle valve at the
idle position: ON
With the throttle valve slight-
ly open: OFFNGCheck the idle position switch system.
(Refer to P.13A-40 INSPECTION
PROCEDURE 25.)
OK
Check the throttle position sensor.
(Refer to P.13A-87.)NG
Replace
OK
Measure at the throttle position sensor
connector A-47.

Disconnect the connector, and
measure at the harness side.

Voltage between 4 and earth
(Ignition switch: ON)
OK:4.8 ± 5.2 V

Continuity between 1 and earth
OK:ContinuityNGCheck the following connector.
C-51NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire between the
engine-ECU and the throttle position
sensor connector.NG
Repair
OK
Replace the engine-ECU. OK
Check the throttle position sensor out-
put circuit. (Refer to P.13A-55, IN-
SPECTION PROCEDURE 46.)