Circuit Description
WARNING: This page is about a different car, the 2003 Lexus SC 430, 2003 Lexus LS 430, 2003 Lexus IS 300, 2003 Lexus GS 430, and 2003 Lexus GS 300. However, it is still accessible from the selected car via links, so may be relevant.
When engine is being cranked, intake airflow is slow, so fuel vaporization is poor. A rich mixture is necessary to achieve good startability. While engine is being cranked, 9-14 volts is supplied to ECM terminal STA. Starter signal is mainly used to increase fuel injection pulse for starting injection control and after-start injection control.
NOTE:
The following test assumes starter cranks normally with ignition in START position. If starter does not crank normally, check and repair starter circuit before continuing with this test.