Circuit Description

When engine is being cranked, intake air flow is slow, so fuel vaporization is poor. A rich mixture is necessary to achieve good startability. While engine is being cranked, battery voltage 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.

DTC is set if there is no starter signal to ECM. Possible causes are:

• Open or short in starter signal circuit.
• Open or short in ignition switch or starter relay circuit.
• ECM.