ASE - Automotive Service Excellence Practice Test #5 1

Question 1

A technician observes Long Term Fuel Trim (LTFT) values of +22% at idle that drop to approximately +5% at 2,500 RPM. Which condition BEST explains this pattern?

Accepted Answer

A vacuum leak introducing unmetered air primarily at idle

Answer

A faulty mass airflow (MAF) sensor reading low across all RPM ranges

Answer

Leaking fuel injectors causing an overly rich mixture

Answer

A restricted catalytic converter increasing backpressure

Question 2

A downstream (post-catalyst) oxygen sensor displays the same rapid, high-amplitude switching pattern as the upstream sensor. What does this waveform indicate?

Accepted Answer

The catalytic converter has low conversion efficiency

Answer

The upstream oxygen sensor has an open heater circuit

Answer

The catalytic converter is storing and releasing oxygen efficiently

Answer

The downstream sensor signal wire is shorted to battery voltage

Question 3

A vehicle equipped with ABS consistently pulls to the right during a hard stop while ABS is actively cycling. Brake fluid level and pad thickness are within spec on all corners. Which component should the technician inspect FIRST?

Accepted Answer

The right-front wheel speed sensor and tone ring

Answer

The brake master cylinder for an internal bypass

Answer

The left-front wheel speed sensor and tone ring

Answer

The hydraulic control unit (HCU) modulator valve

Question 4

An automatic transmission slips specifically during the 2nd-to-3rd gear upshift under heavy throttle. Fluid level, color, and smell are all normal. No other gear changes are affected. Which component is MOST likely at fault?

Accepted Answer

The 2-3 shift solenoid or its wiring circuit

Answer

The torque converter clutch (TCC) solenoid

Answer

The transmission range (TR) sensor

Answer

The turbine (input) speed sensor

Question 5

A smoke test reveals no leaks in the EVAP system. The purge solenoid opens on command and the vent solenoid closes on command, yet the EVAP monitor continues to report incomplete. Which component is MOST likely preventing monitor completion?

Accepted Answer

A faulty fuel tank pressure (FTP) sensor

Answer

A cracked charcoal canister body

Answer

A stuck-open purge valve

Answer

A loose or missing fuel cap

Question 6

A dial indicator measurement shows 0.009 inch of lateral runout on a front brake rotor. The manufacturer's maximum specification is 0.003 inch. Which customer symptom is MOST consistent with this finding?

Accepted Answer

A pulsating brake pedal and steering wheel shimmy during normal braking

Answer

Brake fade and boiling fluid after repeated hard stops on a steep grade

Answer

A continuous metal grinding noise present only at speeds below 10 mph

Answer

ABS activation on dry pavement at light braking pressure