48 Reference Input - Intermittent or Noisy
From SaturnWiki
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Description
The crankshaft position sensor (CPS) defines engine position by generating an electrical pulse each time it passes by a notch of the crankshaft reluctor wheel. The reference pulse is a 5 volt square wave that switches low two times per crankshaft revolution. The PCM uses reference pulses for fuel delivery and spark timing.
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Information Flag Parameters
Information Flag 48 will set if:
- Extra or missing reference pulses are detected.
- Time between reference pulses is too long or too short.
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Diagnostic Aids
- When attempting to diagnose an intermittent problem, use the Scan Tool to review supplemental diagnostic information. The supplemental data can be used to duplicate a problem. Select MALF History from Scan Tool EC menu.
- Check the tightness of the female terminal grip with a spare male terminal.
- Verify that the secondary leads are not in close proximity to the signal wires (EST, REF, etc.).
NOTICE: Information flags should be used for diagnostic purposes only. They do not necessarily indicate component malfunction/failure.
