July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!

Service Engine Soon Indicator

When the ignition is in the ON position the bulb will prove out. During vehicle operation, the malfunction indicator lamp (MIL) illuminates when the PCM has detected a fault. If a fault is detected the PCM sends a signal to the instrument cluster via the SCP (J1850) line and turns on the MIL lamp.