Hello.

Can anybody tell me why the crankshaft sensor is needed when there is a camshaft sensor which in fact can tell about the crankshaft position as well because the camshaft is driven by crankshaft and timing belt. Simple to say, spark timing and fuel injection timings both can be computed from camshaft only so why is there a crankshaft sensor also? I am searching for this answer but can not figure it out.

Regards

 

first question you should ask yourself is what if the jumps a teeth, or someone installs it without the crankshaft not at TDC?

even in that case its still questionable in OB1 Hondas VS OBD2 because in OBD1 the sensors are all in the distributor vs OBD2 which has a crank position sensor on the oil pump. but either way its to tell the ECU that the crank is in sync with the cams so it fires in time.