Circuit Description

Mass Airflow (MAF) meter uses a platinum hot wire which is maintained at a constant temperature by controlling the current flow through the hot wire. Current flow is then measured as an output voltage. MAF meter may also be referred to as airflow meter. DTC is set when ECM detects an open or short in MAF meter circuit for more than 3 seconds with engine speed at 3000 RPM or less. If DTC P0100 exists, ECM will operate in fail-safe mode which keeps ignition timing at 5 degrees BTDC. Possible causes are:

• MAF meter circuit is open or shorted.
• Defective MAF meter.
• Defective ECM.