1997 MITSUBISHI TRITON relay

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 ± 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-15
Code No. 22 Crank angle sensor systemProbable cause
Range of Check

Engine is cranking.
Set conditions

Sensor output voltage does not change for 4 seconds (no pulse signal input.)
Malfunction of the crank angle sensor

Improper connector contact, open circuit or
short-circuited harness wire of the crank angle sensor

Malfunction of the engine-ECU
Measure at the distributor connector A-72.

Connect the connector. (Use the test harness: MB991348.)

Voltage between 2 and earth (Engine: cranking)
OK:0.4 ± 4.0 V

Voltage between 2 and earth (Engine: idling)
OK:1.5 ± 2.5 V
NGOKReplace the engine-ECU.
Measure at the distributor connector A-72.

Disconnect the connector, and measure at the harness side.
1. Voltage between 3 and earth (Ignition switch: ON)
OK:System voltage
2. Voltage between 2 and earth (Ignition switch: ON)
OK:4.8 ± 5.2 V
3. Continuity between 4 and earth
OK:Continuity
OK
Check the following con-
nector. A-72NG
Repair
OK
Check trouble symptom.
NG
Replace the distributor.1. NG
Check the harness wire between the crank angle sensor and the
control relay connector, and repair if necessary.
2. NGCheck the following con-
nector. C-51NG
Repair
OK3. NG
Check trouble symptom.
NG
Check the harness wire
between the engine-ECU and
the distributor connector.NG
Repair
OK
Replace the engine-ECU.
Check the harness wire between the crank angle sensor and the
earth, and repair if necessary.

MPI ± Troubleshooting13A-16
Code No. 23 Top dead centre sensor systemProbable cause
Range of Check

Ignition switch: ON

Engine speed is approx. 50 r/min or more.
Set conditions

Sensor output voltage does not change for 4 seconds (no pulse signal input.)
Malfunction of the camshaft position sensor

Improper connector contact, open circuit or
short-circuited harness wire of the top dead centre
sensor circuit

Malfunction of the engine-ECU
Measure at the distributor connector A-72.

Connect the connector. (Use the test harness: MB991348)

Voltage between 1 and earth (Engine: cranking)
OK:0.4 ± 3.0 V

Voltage between 1 and earth (Engine: idling)
OK:0.5 ± 2.0 VOKReplace the engine-ECU.
NG
Measure at the distributor connector A-72.

Disconnect the connector, and measure at the harness side.
1. Voltage between 3 and earth (Ignition switch: ON)
OK:System voltage
2. Voltage between 1 and earth (Ignition switch: ON)
OK:4.8 ± 5.2 V
3. Continuity between 4 and earth
OK:Continuity1. NGCheck the harness wire between the top dead centre sensor and
the control relay connector, and repair if necessary.
2. NGCheck the following con-
nector. C-51NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire
between the engine-ECU and
the distributor connector.NG
Repair
OK
Replace the engine-ECU. 3. NG
OK
Check the following con-
nector. A-72NG
Repair
OK
Check trouble symptom.
NG
Replace the distributor.
Check the harness wire between the top dead centre sensor and
the earth, and repair if necessary.

MPI ± Troubleshooting13A-30
INSPECTION PROCEDURE 9
Idling speed is high. (Improper idling speed)
Probable cause
In such cases as the above, the cause is probably that the intake air volume during
idling is too great.
Malfunction of the ISC servo system

Malfunction of the throttle body
OK
MUT-II Data list
26 Idle position switch (Refer to P.13A-57.)NGCheck the idle position switch system.
(Refer to P.13A-40, INSPECTION PROCEDURE 25.)
No
Check the ISC servo for operation sound. (Refer to P.13A-90.)NGCheck the ISC servo system.
(Refer to P.13A-45, INSPECTION PROCEDURE 31.)
OK
MUT-II Data list
21 Engine coolant temperature sensor (Refer to P.13A-57.)NGCheck the engine coolant temperature sensor system.
(Refer to P.13A-14, INSPECTION PROCEDURE FOR DIAGNOSIS
CODE 21.)
OK
MUT-II Data list
28 A/C switch (Refer to P.13A-57.)NGCheck the A/C switch and A/C relay system.
(Refer to P.13A-43, INSPECTION PROCEDURE 29.)
OK
Basic idle adjustment (Refer to P.13A-79.)
Check trouble symptom.NGClean the throttle valve area. (Refer to P.13A-78.)
Check and adjust the fixed SAS. (Refer to P.13A-79.)
MUT-II Self-Diag code
Are diagnosis codes displayed?Ye sRefer to P.13A-10, INSPECTION CHART FOR DIAGNOSIS
CODES.

MPI ± Troubleshooting13A-39
INSPECTION PROCEDURE 23
Power supply system and ignition switch-IG system
Probable cause
When an ignition switch ON signal is input to the engine-ECU, the engine-ECU turns
the control relay ON. This causes battery voltage to be supplied to the engine-ECU,
injectors and air flow sensor.
Malfunction of the ignition switch

Malfunction of the control relay

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

Disconnected engine-ECU earth wire

Malfunction of the engine-ECU
Check the control relay. (Refer to P.13A-86.)NG
Replace
OK
Measure at the control relay connector C-53.

Disconnect the connector, and measure at the harness side.

Voltage between 3, 4 and earth
OK:System voltageNGCheck the harness wire between battery and control relay connector,
and repair if necessary.
OK
Check the engine-ECU power supply and earth circuit.
(Refer to P.13A-53, INSPECTION PROCEDURE 42.)

MPI ± Troubleshooting13A-40
INSPECTION PROCEDURE 24
Fuel pump system
Probable cause
The engine-ECU turns the control relay ON when the engine is cranking or running,
and this supplies power to drive the fuel pump.
Malfunction of the fuel pump relay

Malfunction of the fuel pump

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

Malfunction of the engine-ECU
Check the fuel pump operation. (Refer to P.13A-84.)NGCheck the fuel pump circuit.
(Refer to P.13A-53, INSPECTION PROCEDURE 43.)
OK
Check the fuel pump relay. (Refer to P.13A-86.)NG
Replace
OK
Measure at the fuel pump relay connector C-54.

Connect the connector.

Voltage between 1 and earth

MUT-II Actuator test: Fuel pump drive
OK:System voltageNGCheck the fuel pump drive control circuit.
(Refer to P.13A-54, INSPECTION PROCEDURE 44.)
OK
Check the harness wire between fuel pump relay connector and
fuel pump drive terminal, and repair if necessary.
INSPECTION PROCEDURE 25
Idle position switch system
Probable cause
The idle position switch inputs the condition of the accelerator pedal, i.e. whether
it is depressed or released (HIGH/LOW), to the engine-ECU.
The engine-ECU controls the idle speed control servo based on this input.
Maladjustment of the accelerator pedal

Maladjustment of the fixed SAS

Maladjustment of the idle position switch and throttle
position sensor

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

Malfunction of the engine-ECU
Check the idle position switch. (Refer to P.13A-87.)NGReplace
OK
Measure at the throttle position sensor connector A-47.

Disconnect the connector, and measure at the harness side.

Voltage between 2 and earth (Ignition switch: ON)
OK:4 V or higher

Continuity between 1 and earth
OK:ContinuityNGCheck the following
connector. C-51NG
Repair
OK
Check trouble symptom.
NG
Check the harness wire between engine-ECU and throttle position
sensor connector.
OK
Replace the engine-ECU.
NG
Repair
OK
Check the following
connector. A-47NG
Repair
OK
Check trouble symptom.
NG
Replace the engine-ECU.

MPI ± Troubleshooting13A-43
INSPECTION PROCEDURE 28
Power steering fluid pressure switch system
Probable cause
The presence or absence of power steering load is input to the engine-ECU.
The engine-ECU controls the idle speed control (ISC) servo based on this input.
Malfunction of power steering fluid pressure switch

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

Malfunction of the engine-ECU
Check the power steering fluid pressure switch.
(Refer to GROUP 37A ± On-vehicle Service.)NG
Replace
OK
Measure at the power steering fluid pressure switch connector
A-74.

Disconnect the connector, and measure at the harness side.

Voltage between 1 and earth (Ignition switch: ON)
OK:System voltageNGCheck the following
connector. C-50NG
Repair
OK
Check trouble symptom.
NG
Check harness wire be-
tween engine-ECU and
power steering fluid pres-
sure switch connector.NG
Repair
OK
Replace the engine-ECU.
OK
Check the following
connector. A-74NG
Repair
OK
Check trouble symptom.
NG
Replace the engine-ECU.
INSPECTION PROCEDURE 29
A/C switch and A/C relay system
Probable cause
When an A/C ON signal is input to the engine-ECU, the engine-ECU carries out
control of the idle speed control (ISC) servo, and also operates the A/C compressor
magnetic clutch.
Malfunction of A/C control system

Malfunction of A/C switch

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

Malfunction of the engine-ECU
Check the A/C compressor relay.
(Refer to GROUP 55 ± On-vehicle Service.)NG
Replace
OK
Measure at the engine-ECU connectors C-49, C-50.

Disconnect the connector, and measure at the harness side.


Voltage between 22 and earth, and 45 and earth
(Ignition switch: ON, A/C switch: ON)
OK:System voltage

Short circuit between 22 and earth
(Ignition switch: ON, A/C switch: ON)
OK:A/C compressor clutch turns on.


Voltage between 8 and earth, and 45 and earth
(Ignition switch: ON, A/C switch: ON)
OK:System voltage

Short circuit between 8 and earth
(Ignition switch: ON, A/C switch: ON)
OK:A/C compressor clutch turns on.NGCheck the A/C system. (Refer to GROUP 55 ± On-vehicle Service.)
OKCheck the following
connectors. C-49, C-50NG
Replace
OK
Check trouble symptom.
NG
Replace the engine-ECU.