Mitsubishi Electric Lancer Evolution-VII Workshop Manual page 1261

13A-124
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
Rises from approximately 2 V to approximately 4.5 V at the
top-right
2 V rectangular wave
Rectangular wave at power voltage
--- Normal wave pattern
2 V
--- Normal wave pattern
V
B
MPI -
Troubleshooting
Probable cause
Normal
Open-circuit in ignition primary circuit
Power transistor malfunction
Examples of Abnormal Wave Patterns
Example 1
D
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.
Example 2
D
Wave pattern during engine cranking
Cause of problem
Malfunction in power transistor
Wave pattern characteristics
Power voltage results when the power transistor is ON.