Circuit Description

The powertrain control module (PCM) uses the following readings to calculate the predicted mass air flow (MAF) rate:

• The throttle position (TP)
• The barometric pressure (BARO)
• The intake air temperature (IAT)
• The engine RPM

The PCM compares the predicted MAF value to the actual MAF value, and to the speed density calculation, in order to verify the proper throttle operation.