So, crankshaft camshaft sensors, are both required by, distributorless ignition systems (DIS).

Because, engines rely on signals from both, to determine, when to fire the spark and inject the fuel.

The most important sensors of any engine, the crankshaft and camshaft position sensors; are crucial to the functionality of the fuel and ignition timing.

Crankshaft Camshaft Sensors, detect camshaft and crankshaft rotation, during one engine-combustion cycle.

The Camshaft Position sensor, is typically located, in the cylinder head of the engine. However, the Crankshaft Position sensor, is normally located, in the timing cover or on the side of the engine block.

So, the (ECM) uses signal pulses from both sensors to gain information:

  • To calculate when a particular cylinder, is approaching top dead center.
  • To decide when it is on a, compression or an exhaust stroke.

So, if either signal is lost, the (ECM) may decide to, shut down ignition, injection or both. In addition, sensor failures are, extremely common on certain makes. So, it was not that long ago, that a failed sensor would cause; a no start or an engine that just died. But, today many engines can overcome this problem, with the limp home feature.

Above all, the relationship between the two signals, is as important, as the signals themselves. Also, some trouble codes (DTC)s are related to the loss of, camshaft/crankshaft signal.

Common problems that can cause issues with, sensor signals include:

  • Accumulation of dirt, on the sensor tip.
  • Stretched timing belts and chains.
  • Cracked flex-plates and wiring connector problems.
  • Excessive end play on crankshafts and camshafts, can also cause variations in the signal.

Finally, both sensors usually fail slowly, as the signal to the (PCM) weakens.


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