Note. If DTCs P0100, P0101, P0110, P0115 and P0120 are output together, check circuit E2 (White wire) between terminal No. 18 at ECM harness connector E8 and splice E9. Repair as necessary. See WIRING DIAGRAMS article.
Note. For component location, see appropriate illustration in THEORY & OPERATION article.
Circuit Description
Mass Airflow Meter (MAF) meter uses a platinum hot wire maintained at a constant temperature. Airflow past meter affects temperature and current flow through MAF meter. DTC is set when ECM detects either throttle valve is fully closed and MAF meter output is more than 2.2 volts for more than 10 seconds with engine speed at 900 RPM or less, or VTA circuit signal is .63 volt or more and MAF meter output is less than 1.06 volts for more than 10 seconds with engine speed at 1500 RPM or more. Possible cause is defective MAF meter.
Diagnostic Aids
Using Toyota hand-held tester or scan tool, check for any other DTCs. If other DTCs exist, diagnose and repair those DTCs first and retest. If only DTC P0101 exists, replace MAF meter.