Code 48, Mass Airflow Sensor: Notes
WARNING: This page is about a different car, the 1994 Cadillac Fleetwood. However, it is still accessible from the selected car via links, so may be relevant.
Mass airflow meter measures amount of induction airflow. This information is used by PCM to determine adjustments to air/fuel ratio. MAF sensor is a hot-wire type. Sensor maintains hot wire at a predetermined temperature. The greater the airflow across the hot wire, the more current is required to maintain hot wire temperature. Sensor changes the current requirements into a frequency signal which is read by the PCM. The PCM calculates airflow based upon this signal.
NOTE:
Test numbers refer to numbers on diagnostic charts.
- Determines if fault is a hard failure or an intermittent condition.
- Checks for 5-volt reference from PCM.
- Verifies both ignition voltage and a good ground circuit are available.