Engine Performance (A8)Question 101 of 120
A knock sensor allows the PCM to:
a.Measure exhaust oxygen
b.Detect detonation and retard ignition timing to protect the engine
c.Control the fuel pump
d.Read vehicle speed
Explanation
The knock sensor detects the vibration of detonation so the PCM can retard timing and prevent engine damage. Persistent knock can come from low-octane fuel, carbon buildup, or overheating. A faulty sensor may cause reduced performance or a code.
Practice all 120 questions free — no signup required.
Related questions on this topic
- Technician A says the MAF sensor measures the mass of air entering the engine so the PCM can meter fuel. Technician B says a dirty MAF can cause hesitation and fuel-trim errors. Who is correct?
- A P0420 code (catalyst efficiency below threshold) most often indicates:
- In a modern coil-on-plug ignition system, each coil:
- The EVAP system is designed to:
- A loose or missing fuel cap most commonly sets which type of code?
- Technician A says low fuel pressure can cause a lean misfire and hesitation. Technician B says a clogged fuel filter or weak pump can lower fuel pressure. Who is correct?
Last reviewed: · editorial process
PrepPass Editorial Team · Verified against ASE Automobile Certification Series (A1–A8) · How we review