Service Engine Soon Indicator Lamp

The Service Engine Soon indicator lamp should turn on when the ignition switch is in the RUN position and with the engine off. The lamp should turn off 1-5 seconds after the engine starts. If the lamp stays on, or turns on while driving, this may require service to the emission control system. Refer to A Powertrain On Board Diagnostic (OBD) System Check or A Powertrain On Board Diagnostic (OBD) System Check or A Powertrain On Board Diagnostic (OBD) System Check in Computers and Control Systems.