A counterman claims that a bad crank position sensor may prevent an engine from starting. Another counterman asserts that ignition coil output voltage drops as spark plugs wear. Who is correct?

The assertion made by the first counterman regarding the crank position sensor is accurate. A crank position sensor plays a critical role in the engine management system by monitoring the position and rotational speed of the crankshaft. This information is vital for the engine control unit (ECU) to manage fuel injection and ignition timing. If the crank position sensor is malfunctioning or defective, it can prevent the engine from starting because the ECU may not receive the necessary information to initiate the starting sequence.

On the other hand, while it's true that spark plugs can experience wear over time, affecting engine performance, the claim about the ignition coil’s output voltage decreasing as spark plugs wear is less straightforward. While worn spark plugs can cause misfires and affect overall engine efficiency, the output voltage of the ignition coil itself does not necessarily decrease directly due to spark plug wear. Instead, the ignition coil generates sufficient voltage to fire the spark plugs under normal conditions, although inefficiencies can arise if the spark plugs are significantly worn, leading to poor combustion. However, this nuance makes the second counterman’s statement less precise or potentially misleading.

Therefore, the correct conclusion is that the first counterman is accurate in his claim regarding the crank position sensor affecting engine start, while the second counterman’s