Circuit Description
WARNING: This page is about a different car, the 2005 GMC Yukon XL, 2005 Chevrolet Suburban, and 2005 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
The powertrain control module (PCM) uses the following readings in order to calculate the predicted mass air flow (MAF) rate:
- The throttle position (TP)
- The barometric (BARO) pressure
- The intake air temperature (IAT)
- The engine revolutions per minute (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.