Ignition Systems Questions and Answers

Answer: A

With nowhere to discharge, the voltage climbs until it finds a path through the insulation. The switching device genuinely does see a higher reflected voltage, which makes the last option a real accompanying risk. Never run an engine with a lead disconnected. The shared behaviour explains why these belong together and the differences explain why both exist. Tracing the requirement back to the physical constraint that produces it makes the answer follow.

Answer: B

Heat related coil failure is common and a meter test when cold shows nothing wrong. Crankshaft sensors genuinely fail in exactly the same heat related way, which makes the last option a real alternative worth excluding. Naming the cost of a choice alongside its benefit is what turns a fact into a design decision. The shared behaviour explains why these belong together and the differences explain why both exist.

Answer: C

The fault must be present to be found, so the test is made hot. Applying heat deliberately with a gun, or freezer spray to cool, is genuinely the standard technique, which makes the last option a real and often better method. Reading the definition literally, rather than recalling a summary, avoids the usual confusion. Naming the cost of a choice alongside its benefit is what turns a fact into a design decision.

Answer: D

Freeze frame stores speed, load, temperature and fuel trim at the moment of the fault, which narrows the search greatly. A road test data log genuinely is the next step, which makes the last option a real and complementary technique. Most errors here come from carrying across a result from a neighbouring case where it does not hold. Reading the definition literally, rather than recalling a summary, avoids the usual confusion.

Answer: A

A misfire from any cause sends oxygen to the sensor, but the pattern of trim and the response to swapping components separate the two. Air flow genuinely changes with a misfire, which makes the last option a real if ambiguous indicator. Naming what changes and what stays the same is the reliable route through questions of this shape. Most errors here come from carrying across a result from a neighbouring case where it does not hold.

Answer: B

If the misfire follows the coil to the new cylinder, the coil is at fault. Disconnecting cylinders in turn genuinely is a recognised technique, which makes the last option a real if cruder method that risks the catalyst. Working the distinction through on a single concrete case fixes it more firmly than any rule of thumb. Naming what changes and what stays the same is the reliable route through questions of this shape.