Circuit Description

Mass Airflow (MAF) sensor measure amount of air entering engine at a given time to determine fuel delivery. MAF sensor information is used for fuel delivery calculations. MAF sensor produces a frequency signal which can be monitored by a scan tool.

Conditions for setting DTC:

• Engine is running.
• No TP or MAP sensor DTCs are set.
• No EVAP DTCs are set.
• EGR DTC P0401 not set.
• MAF related DTCs not set.
• System voltage between 11-16 volts.
• Canister purge duty cycle less than 99.6 percent.
• Change in throttle position is less than 3.9 percent.
• EGR duty cycle not greater than 89.9 percent.
• EGR pintle position not greater than 89.9 percent.
• Engine vacuum is 75 kPa or less.
• Throttle position not greater than 89.8 percent.
• Conditions are met for greater than 2 seconds.