Technician A says the learned LTFT corrections are used as a new base line for STFT. Technician B says the STFT values are constantly adjusted by the PCM to correct for rich/lean running conditions. Who is correct?
A) A only
B) B only
C) both A and B
D) neither A nor B

Question

Quizplus · Accepted Answer

Both technicians are correct. Technician A is correct in stating that learned Long Term Fuel Trim (LTFT) corrections serve as a new baseline for Short Term Fuel Trim (STFT) adjustments. Technician B is correct in stating that the Powertrain Control Module (PCM) constantly adjusts STFT values to correct for rich or lean running conditions.

Technician a Says the Learned LTFT Corrections Are Used as a New