Mitsubishi Outlander XL. Manual - part 420

Examples of Abnormal Wave Patterns

ZK601088AA00

Example 1

Cause of problem

｠

Malfunction of motor. (Motor is not operating.)

Wave pattern characteristics

｠

Induced electromotive force from the motor turning does
not appear.

 

ZK601089

OPEN
CIRCUIT
SIDE

NORMAL
SIDE

AA00

Example 2

Cause of problem

｠

Open circuit in the line between the EGR valve and the
ECM.

Wave pattern characteristics

｠

Current is not supplied to the motor coil on the open circuit
side. (Voltage does not drop to 0 volt.) Furthermore, the
induced electromotive force wave pattern at the normal
side is slightly different from the normal wave pattern.

IGNITION COIL AND IGNITION POWER

TRANSISTOR

Required Special Tools:

｠

MB991658: Test Harness

｠

MB992110: Power Plant ECU Check Harness

Measurement Method

1

2

3

6

7

8

4

5

9 10

ZK603391

Oscilloscope

MB991658

B-21 Intermediate
connector

AA00

Measure at the right bank (number 1, 3, 5 cylinders)

1.

Disconnect  the  intermediate  connector  B-21,  and  connect
the  test  harness  special  tool  (MB991658)  between  the
separated connector.

2.

Connect  the  oscilloscope  probe  to  each  intermediate
connector B-21 terminal to analyze each cylinder:

｠

Terminal No. 2 for the number 1 cylinder.

｠

Terminal No. 3 for the number 3 cylinder.

｠

Terminal No. 4 for the number 5 cylinder.

ZK603393

2 3

1

Ignition coil
connector

Oscilloscope

MB991658

AA00

Measure at the left bank (number 2, 4, 6 cylinders)

1.

Disconnect  the  ignition  coil  connector,  and  connect  test
harness  special  tool  (MB991658)  between  the  separated
connector. (All terminals should be connected.)

2.

Connect  the  oscilloscope  probe  to  ignition  coil  connector
terminal No. 2.

MULTIPORT INJECTION SYSTEM (MFI) <DIAGNOSIS>

13Ab-875

INSPECTION PROCEDURE USING AN OSCILLOSCOPE

 

Alternate method

16 15 14 13 12 11 10 9 8 7 6 5 4 3

2

1

32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17

48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33

64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49

ZK603390 AA00

Power Plant ECU
Check Harness Connector

MB992110

1.

Disconnect all ECM connectors. Connect the check harness
special tool (MB992110) between the separated connectors.

2.

Connect  the  oscilloscope  probe  to  each  check  harness
connector terminal to analyze each cylinder:

｠

Terminal No. 4 for the number 1 cylinder.

｠

Terminal No. 5 for the number 2 cylinder.

｠

Terminal No. 20 for the number 3 cylinder.

｠

Terminal No. 21 for the number 4 cylinder.

｠

Terminal No. 52 for the number 5 cylinder.

｠

Terminal No. 53 for the number 6 cylinder.

Standard Wave Pattern

Observation condition
Function

Special pattern

Pattern height

Low

Pattern selector

Display

Engine r/min

Idle speed

ZK603397

TDC

5°BTDC

ON

Time

AA00

OFF

Ignition power
transistor
control signal
wave pattern

Standard wave pattern

Ignition
timing

Dwell
section

5

10

0

0

2 Engine revolution (1 camshaft revolution)

(Volt)

Crankshaft position
sensor output
wave pattern

Wave Pattern Observation Points

Point: The power transistor control signal (ignition timing) is
advanced when the engine speed is increased.

13Ab-876

MULTIPORT INJECTION SYSTEM (MFI) <DIAGNOSIS>

INSPECTION PROCEDURE USING AN OSCILLOSCOPE

CONDITION

 OF

 WAVE

PATTERN

 BUILD-UP

SECTION  AND  MAXIMUM
VOLTAGE

PROBABLE CAUSE

Voltage value is too low

Open-circuit in ignition primary
circuit

Examples of Abnormal Wave Patterns

ZK601094

NORMAL WAVE
PATTERN

AA00

Example 1 (Wave pattern during engine cranking)

｠

Cause of problem
Open-circuit in ignition primary circuit

｠

Wave pattern characteristics
Voltage value is too low.

MULTIPORT INJECTION SYSTEM (MFI) <DIAGNOSIS>

13Ab-877

INSPECTION PROCEDURE USING AN OSCILLOSCOPE

MEMO

13Ab-878

MULTIPORT INJECTION SYSTEM (MFI) <DIAGNOSIS>