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Wave Pattern Inspection Using an Analyzer




MEASUREMENT METHOD
1. Disconnect the connector of the distributor and connect the special tool (test harness: MB991348) across the disconnected connector parts. (Connect the tool to all terminals.)
2. Connect the special patterns pick-up of the analyzer to the terminal 3 of the distributor connector (in order to inspect the signal waveform of the camshaft position sensor).
3. Disconnect the connector of the crankshaft position sensor, and connect the special tool (test harness: MD998478) across the disconnected connector parts.
4. Connect the special patterns pick-up of the analyzer to the terminal 2 of the crankshaft position sensor connector (in order to inspect the signal waveform of the crankshaft position sensor).

ALTERNATE METHOD (TEST HARNESS NOT AVAILABLE)
1. Connect the analyzer special patterns pick-up to ECM terminal 88 (When inspecting the camshaft position sensor signal wave pattern.)
2. Connect the analyzer special patterns pick-up to ECM terminal 89 (When inspecting the crankshaft position sensor signal 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