Oscilloscope Patterns and Waveforms

WAVE PATTERN INSPECTION USING AN ANALYZER MEASUREMENT METHOD
1. Disconnect the camshaft position sensor & crankshaft position sensor connector and connect the special tool (test harness: MB991348) in between. (All terminals should be connected.)

2. Connect the analyzer special patterns pickup to camshaft position sensor & crankshaft position sensor connector terminal A. (When checking the camshaft position sensor signal wave pattern)

3. Connect the analyzer special patterns pickup to camshaft position sensor & crankshaft position sensor connector terminal 3%. (When inspecting the crankshaft position sensor signal wave pattern.)


ALTERNATE METHOD (TEST HARNESS NOT AVAILABLE)
1. Connect the analyzer special patterns pickup to ECM terminal 68. (When inspecting the camshaft position sensor signal wave pattern.)

2. Connect the analyzer special patterns pickup to ECM terminal 69. (When inspecting the crankshaft position sensor signal wave pattern.)





STANDARD WAVE PATTERN
Wave pattern observation points: Check to be sure that cycle time T becomes shorter when the engine speed increases.

EXAMPLES OF ABNORMAL WAVE PATTERNS






Example 1

Cause of problem - Sensor interface malfunction

Wave pattern characteristics - Rectangular wave pattern is output even when the engine is not started.






Example 2

Cause of problem - Loose timing belt, Abnormality in sensor disk

Wave pattern characteristics - Wave pattern jumps to the left or right.