Possible Causes
WARNING: This page is about a different car, the 2003 Toyota Prius. However, it is still accessible from the selected car via links, so may be relevant.
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.