ASE Ignition Systems 2

Question 1

What typically causes carbon tracking on a spark plug boot or ignition coil tower?

Accepted Answer

Compromised insulation allowing voltage to arc along the surface to ground

Answer

Carbon tracking results from high-voltage arcing along the surface of degraded insulation, depositing conductive carbon that creates a permanent low-resistance path causing misfires.

Question 2

What is the primary function of the ignition control module (ICM)?

Accepted Answer

Switch primary coil current on and off to induce secondary high voltage

Answer

The ICM switches the primary coil circuit on and off based on PCM signals; when primary current is interrupted, the collapsing magnetic field induces high voltage in the secondary winding.

Question 3

Which spark plug electrode material offers the longest service life in modern vehicles?

Accepted Answer

Platinum or iridium

Answer

Platinum and iridium have extremely high melting points and corrosion resistance, allowing extended service intervals of up to 60,000–100,000 miles.

Question 4

Abnormally high secondary ignition circuit resistance most commonly indicates what condition?

Accepted Answer

Worn spark plug electrodes, a wide plug gap, or damaged spark plug wires

Answer

High secondary resistance is most often caused by worn plug electrodes with increased gaps, carbon/oil fouling, or deteriorated high-voltage spark plug wires.

Question 5

In a distributor-less ignition (DIS) system, what does the camshaft position sensor determine?

Accepted Answer

Which cylinder is on its compression stroke to fire the correct coil

Answer

The camshaft position sensor provides cylinder identification — telling the PCM which cylinder is approaching TDC on compression so the correct coil is fired.

ASE - Automotive Service Excellence Certified Tech Practice Test

ASE - Automotive Service Excellence Certified Tech Practice Test

ASE Ignition Systems 2