Mitsubishi Pajero Pinin. Manual - part 127

 

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Mitsubishi Pajero Pinin. Manual - part 127

 

 

MPI <4G9> – 

Troubleshooting

13C-94

IGNITION COIL AND POWER TRANSISTOR

D

Ignition coil primary signal
Refer to GROUP 16 – Ignition system.

D

Power transistor control signal

Measurement Method

1.

Disconnect the ignition coil connector, and connect the
special tool (test harness: MB991348) in between. (All
terminals should be connected.)

2.

Connect the analyzer special patterns pickup to terminal
3 of each ignition coil connector in turn.

Alternate Method (Test harness not available)

1.

Connect the analyzer special patterns pickup to
engine-ECU terminal 10 (No. 1 – No. 4), terminal 23 (No.
2  – No. 3) respectively.

Standard Wave Pattern

Observation condition

Function

Special patterns

Pattern height

Low

Pattern selector

Display

Engine r/min

Approx. 1,200 r/min

Standard wave pattern

Crank angle 
sensor output
wave pattern

Power transistor
control signal 
wave pattern

(V)

75

_

BTDC

5

_

BTDC

Compression top dead center

Ignition period

OFF

ON

Dwell section

T :Crank angle
T1 : Time computed by the engine-ECU

θ

: Spark advance angle

(ms)

θ

T1

T

6

4

2

0

4

2

0

Special
patterns
pickup

Analyzer

MPI <4G9> – 

Troubleshooting

13C-95

Wave Pattern Observation Points

Point: Condition of wave pattern build-up section and maximum voltage (Refer to abnormal wave pattern
examples 1 and 2.)

Condition of wave pattern build-up section and maximum voltage

Probable cause

Rises from approx. 2 V to approx. 4.5 V at the top-right

Normal

2 V rectangular wave

Open-circuit in ignition primary circuit

Rectangular wave at power voltage

Power transistor malfunction

Examples of Abnormal Wave Patterns

D

Example 1

Wave pattern during engine cranking

Cause of problem

Open-circuit in ignition primary circuit

Wave pattern characteristics

Top-right part of the build-up section cannot be seen, and
voltage value is approximately 2 V too low.

D

Example 2

Wave pattern during engine cranking

Cause of problem

Malfunction in power transistor

Wave pattern characteristics

Power voltage results when the power transistor is ON.

--- Normal wave pattern

2V

V

B

--- Normal wave pattern

MPI <4G9> – 

On-vehicle Service

13C-96

ON-VEHICLE SERVICE

THROTTLE BODY (THROTTLE VALVE AREA)
CLEANING

1.

Disconnect the air intake hose from the throttle body.

2.

Apply some detergent to a clean cloth.

3.

Use the clean cloth with detergent to wipe the area around
the throttle valve until it is clean.

Caution
(1) Do not let any of the detergent get directly onto

the throttle valve.

(2) Take care not to let any detergent get into the

motor through the bypass passage. Furthermore,
do not let it get to the sensor through the shaft.

(3) Do not wipe the molybdenum coating which is

located around the throttle valve shaft.

4.

Connect the air intake hose.

5.

Adjust the standard idle speed.

THROTTLE POSITION SENSOR ADJUSTMENT

1.

Turn the ignition switch to LOCK (OFF) position.

2.

Connect the MUT-

II

 to the diagnosis connector.

When not using the MUT-

II, 

proceed as follows:

(1) Disconnect the throttle position sensor connector, and

connect the special tool (throttle position sensor test
harness: MB991536) between the disconnected
connector taking care not to confuse the terminal to
be connected.

(2) Connect digital voltmeter between the terminal No.2

(sensor output: blue clip of special tool) and the
terminal No.4 (sensor earth: black clip of special tool)
of the throttle position sensor connector.

3.

Turn the ignition switch to ON (but do not start the engine).

4.

Check the output voltage of the throttle position sensor.

Standard value: 535 – 735 mV

Throttle valve 
molybdenum coating

15 mm

15 mm

Throttle position
sensor

Equipment
side connector

MB991536

Throttle position
sensor

MPI <4G9> – 

On-vehicle Service

13C-97

5.

If not within the standard value, loosen the throttle position
sensor mounting bolts. Then rotate the sensor body to
adjust.

6.

Turn the ignition switch to LOCK (OFF) position.

7.

Remove the MUT-

II

. If the MUT-

II

 is not used, remove

the special tool, and then connect the throttle position
sensor connector.

8.

If a diagnosis code is displayed, erase the diagnosis code
by using the MUT-

II

 or disconnect the negative battery

cable from the battery terminal and then leave it for at
least ten seconds. After that, reconnect the battery cable,
and then let the engine run at idle for approx. ten minutes.

BASIC IDLE SPEED ADJUSTMENT

NOTE
(1) The standard idling speed has been adjusted by the

speed adjusting screw (SAS) by the manufacturer,
and there should usually be no need for readjustment.

(2) If the adjustment has been changed by mistake, the

idle speed may become too high or the idle speed
may drop too low when loads from components such
as the A/C are placed on the engine. If this occurs,
adjust by the following procedure.

(3) The adjustment, if made, should be made after first

confirming that the spark plugs, the injectors, the idle
speed control servo, the compression pressure, etc.,
are all normal.

1.

Before inspection and adjustment, set the vehicle to the
pre-inspection condition.

2.

Turn the ignition switch to LOCK (OFF) position.

3.

Connect the MUT-

II

 to the diagnosis connector (16-pin).

NOTE
When the MUT-

II

 is connected, the diagnosis control

terminal should be earthed.

4.

Start the engine and run at idle.

5.

Select the item No.30 of the MUT-

II

 Actuator test.

NOTE
This holds the ISC servo at the basic step to adjust the
basic idle speed.

6.

Check the idle speed.

Standard value: 700 

±

 50 r/min

NOTE
(1) The engine speed may be 20 to 100 r/min lower than

indicated above for a new vehicle [driven
approximately 500 km or less], but no adjustment is
necessary.

(2) If the engine stalls or the engine speed is low even

though the vehicle has been driven approximately 500
km or more, it is probable that deposits are adhered
to the throttle valve, so clean it. (Refer to P.13C-96.)

 

 

 

 

 

 

 

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