Circuit Description
WARNING: This page is about a different car, the 2007 Isuzu i-370, 2007 GMC Canyon, and 2007 Chevrolet Colorado. However, it is still accessible from the selected car via links, so may be relevant.
The powertrain control module (PCM) uses the following information to calculate an expected airflow rate:
- The throttle position
- The barometric pressure (BARO)
- The manifold absolute pressure (MAP)
- The intake air temperature (IAT)
- The mass air flow (MAF)
- The engine speed (RPM)
If the PCM detects the airflow rate is more than expected, DTC P0121 sets.