What is the most likely cause of the concern indicated by the PID?

• A. faulty MAF
• B. dirty MAF
• C. faulty MAP
• D. dirty MAP

Answer: (A)

The signal in the PID points to an air flow measurement issue from the sensor that directly measures incoming air mass. When the ECU relies on that reading to meter fuel, a fault in the MAF sensor tends to cause consistently incorrect air mass data, which shows up in the PID as abnormal or non-responsive airflow values as engine speed and load change. A faulty MAF disrupts fueling more reliably than a dirty one, because the sensor may be delivering wrong data all the time rather than just being temporarily contaminated. A dirty MAF can cause similar symptoms, but cleaning it often resolves those readings, whereas a genuine fault in the MAF typically remains, making it the more likely cause. The MAP sensor can also affect readings, but its failure pattern differs (manifold pressure readings that don’t align with engine load/voltage behavior), so it’s less likely to be the source of the PID concern in this scenario.