Engine Performance & Diagnostics Flashcards
6 cards from real ASE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Engine Performance & Diagnostics flashcards as text
What is the primary purpose of an engine control module (ECM)?
Answer: To regulate fuel injection and ignition timing
The ECM manages engine functions such as fuel injection, ignition timing, and emissions control to ensure optimal performance.
Which sensor is responsible for measuring the oxygen levels in the exhaust system?
Answer: Oxygen sensor
The oxygen sensor monitors exhaust gases to help adjust the air-fuel mixture for efficient combustion and lower emissions.
What could cause a vehicle to have poor fuel efficiency?
Answer: Faulty oxygen sensor or clogged injectors
Factors such as faulty oxygen sensors, clogged fuel injectors, and incorrect tire pressure can lead to decreased fuel efficiency.
Why is it important to diagnose misfires in an engine?
Answer: To prevent engine damage and performance issues
Engine misfires can lead to reduced power, poor fuel economy, increased emissions, and potential damage to engine components if not addressed.
What tool is commonly used to diagnose engine problems by retrieving trouble codes?
Answer: OBD-II scanner
An OBD-II scanner is used to retrieve diagnostic trouble codes (DTCs) from the engine control module, aiding in pinpointing engine issues.
Which of the following is a symptom of a failing catalytic converter?
Answer: Reduced engine performance and rotten egg smell
A failing catalytic converter can cause reduced engine performance, increased emissions, and a rotten egg smell due to unprocessed fuel vapors.