Circuit Description

MAF sensor is a high frequency device that measures the rate of airflow through the throttle body. MAF sensor outputs a series of pulses that varies in frequency with airflow. VCM uses this signal for fuel control.

MAF sensor readings during acceleration will be much higher than those during deceleration or idle. VCM calculates what MAF sensor reading should be from the sensor under certain conditions using engine speed (RPM) and barometric pressure parameters. When certain test conditions are met, PCM will compare its calculated MAF value to the actual value received from the sensor. If difference between calculated MAF and actual MAF is too great, DTC P0101 will set.

For duplication of DTC, ensure:

• Other DTCs are not set.
• System voltage is 11-16 volts.
• Canister purge duty cycle is less than or equal to 99.6 percent.
• EGR pintle position and duty cycle is less than 90 percent.
• TP sensor voltage is steady.
• Throttle position is less than 90 percent.