ASE A6 Electrical Electronics Practice Test

Wastespark ignition system.

47. A four-cylinder engine's #2 and #3 cylinders produce less secondary voltage than the #1 and #4 cylinders. According to the diagram above, which of the following is causing this condition?

  • A. There is an open at point A of the ignition system.
  • B. There is an open at point C of the ignition system.
  • C. There is resistance at point C of the ignition system.
  • D. There is resistance at point D of the ignition system.
Wastespark ignition system.


Answer A is wrong. Answer C is correct.

Answer B is wrong. An open at point C results in no spark at the #2 and #3 cylinders.

Answer C is correct. Resistance at point C in the 2-3 coil’s power circuit will only result in low output at the 2-3 coil. This is because reduced primary voltage caused by electrical resistance produces low secondary voltage output. Perform a voltage drop test to confirm.

Answer D is wrong. Resistance in the crankshaft position sensor’s circuit will result in a corrupt signal and a likely no-spark condition at both coils.