While discussing the diagnosis of an EI system in which the crankshaft and camshaft sensor tests are satisfactory but a spark tester connected from the spark plug wires to ground does not fire, Technician A says the coil assembly may be defective. Technician B says the voltage supply wire to the coil assembly maybe open. Who is correct?

Both A and B  are correct.

Explanation:

The crankshaft sensor is attached to the crankshaft pulley on the

back side of the crankshaft. It is used to pass a signal to the PCM

which controls the ignition of an engine. This sensor helps in providing some basic timing for the signal. If there is a faulty sensor present, the signal will not be received by the PCM. So, it will affect the engine while starting. One reason can be a defective

assembly of the coil.

If there is a faulty , the signal will not be received properly. This will not allow the passing of signals to the ignition system. This will cause a misfire. One of the most common causes of

misfire is a faulty ignition coil. This will affect the working of a

sensor. So, prevent engine from starting.

it was a fall down when it happens

explanation: