ASE4 Computerized Engine Controls 3

Question 1

When using a scan tool to monitor freeze frame data, the technician can determine:

Accepted Answer

The engine operating conditions at the moment a fault code was set

Answer

Freeze frame data captures a snapshot of sensor values at the exact moment a fault code was triggered, aiding diagnosis.

Question 2

A knock sensor DTC is set and the engine has excessive spark retard. The knock sensor circuit tests good. The NEXT step is to:

Accepted Answer

Check for carbon deposits causing actual detonation

Answer

If the knock sensor and circuit are good, actual detonation from engine problems like carbon deposits may be triggering the sensor correctly.

Question 3

The VVT (Variable Valve Timing) system uses which parameter to control camshaft advance?

Accepted Answer

Oil pressure delivered via ECM-controlled solenoids

Answer

VVT systems use engine oil pressure directed by ECM-controlled solenoids to hydraulically advance or retard the camshaft timing.

Question 4

A P0016 code (Crankshaft/Camshaft Correlation Bank 1, Sensor A) is stored. This indicates:

Accepted Answer

The camshaft is not in the expected position relative to the crankshaft

Answer

P0016 means the ECM detected a correlation error between CKP and CMP signals — the cam and crank timing do not match the expected relationship.

Question 5

What is the purpose of the ECM's adaptive fuel strategy (long-term fuel trim)?

Accepted Answer

To learn and compensate for long-term changes in engine components

Answer

Long-term fuel trim allows the ECM to permanently adjust base fuel delivery to compensate for gradual changes like injector wear or sensor drift.

ASE4 - ASE Automobile Engine Performance Practice Test