Summit L4-1795cc 1.8L SOHC (1995)
Condition of wave pattern
Probable cause
build-up section and
maximum voltage
Rises from approx. 2V to
approx. 4.5V at the top-right
Normal
2V rectangular wave
Open-circuit in ignition primary circuit
Rectangular wave at power voltage
Ignition power transistor malfunction
EXAMPLES OF ABNORMAL WAVE PATTERNS
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 2V too low.
Example 2
Wave pattern during engine cranking
Cause of problem: Malfunction in ignition power transistor
Wave pattern characteristics: Power voltage results when the ignition power transistor is ON.