Circuit Description

PCM receives an on/off signal from stoplight switch. When PCM receives an off signal from stoplight switch, PCM will allow A/T Torque Converter Clutch (TCC) to lock-up. DTC P1520 will set when engine is at normal operating temperature and stoplight switch remains on. When DTC sets, MIL will illuminate. PCM will record operating conditions at time of failure and store information in freeze frame buffer.