Service Engine Soon Indicator
The SERVICE ENGINE SOON indicator is controlled by the Powertrain Control Module
(PCM) through circuit 419. The PCM will turn the indicator on for approximately three seconds during engine start-up for a bulb check. The PCM will illuminate the SERVICE ENGINE SOON indicator to warn the driver that an engine control malfunction has been detected which may affect engine performance. For more information, refer to
Engine Controls.
Computers and Control Systems