Mass Air Flow (MAF) sensors measure the weight and rate of air moving through a passage of a known volume or size. MAF sensors utilize hot wire or thick film technology. Signals generated may be analog or digital depending on the manufacturer. As more air passes through the MAF sensor the voltage or frequency increases proportionally. The EMS uses this information to calculate injector pulse-width and spark advance. Performance issues from MAF sensor failures range from no-start conditions to stalling, hesitation, stumble and improper air/fuel mixtures.
A faulty MAF sensor due to loose connections, bad grounds, high resistance in the circuit, or opens in the circuit can cause the following symptoms: