Air Flow Meter/Sensor Relay: Description and Operation

Mass Air Flow Relay:

Due to contaminants in the atmosphere, a residue may build up on a Mass Air Flow (MAF) Sensor sensing wire. To maintain an accurate reading from the sensor, a burn-off cycle will occur when the ignition is turned off after the the engine has been running a specific amount of time and the engine is warmed up.

The burn-off function is enabled when the ECM energizes the MAF sensor burn-off relay. With the MAF sensor burn-off relay energized, voltage will be supplied to the MAF Sensor. Voltage will also be supplied through the normally closed set of contacts in the MAF power relay in some models which will supply 12 volts to the MAF Sensor.