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. PCM also uses stoplight switch input for fuel cut-off control. DTC P1520 will set when vehicle speed is greater than 19 MPH and stoplight switch remains on. When DTC sets, MIL will illuminate after 2 consecutive ignition cycles in which diagnostic runs with active fault. PCM will record operating conditions at time of failure and store information in freeze frame buffer.