Ignition System Test

Step by step guide on how to test an automotive engine's ignition system, this article pertains to most ignition systems.

Difficulty Scale: 4 of 10

Tools and Supplies Needed

  • Voltmeter
  • Test light
  • Socket set
  • Wrench set
  • Needle nose pliers
  • Shop towels
  • Protective eyewear and gloves
  • Small wire or paper clip
  • Screwdriver set

Begin with the car on level ground, in park with the emergency brake on.

Step 1 - Identify the type of ignition system to be tested, most cars, use a coil over plug (COP) type of system. There are several variations but all work on the same principal.

Coil Over Plug Ignition System

Step 2 - When checking for a misfire while the engine is still running, the fuel pump must be disabled to avoid accidental ignition discharge. Using the owners manual identify the fuse location.

Fuel Pump Fuse

Step 3 - Once the fuse is located use needle nose pliers or a fuse removal tool to remove the fuel pump fuse from the power distribution center (PDC.)

Removing Fuel Pump Fuse

Step 4 - Remove the safety from the coil electrical connector (red.) Some cars are not equipped with this feature.

Remove Ignition Coil Safety


Written by
Co-Founder and CEO of
35 years in the automotive repair field, ASE Master Technician, Advanced Electrical and Mechanical Theory.


Please use our question form if you have a specific question about your car as we are not able to give you a full answer on this page.

Article first published (Updated 2013-12-07)