Your vehicle is equipped with a computer that monitors the engine’s emission control system. This system is commonly known as the On Board Diagnostics System (OBD II). This OBD II system protects the environment by ensuring that your vehicle continues to meet government emission standards. The OBD II system also assists the service technician in properly servicing your vehicle.
The Service Engine Soon indicator light illuminates when the ignition is first turned to the ON position to check the bulb. If it comes on after the engine is started, one of the engine’s emission control systems may be malfunctioning. The light may illuminate without a driveability concern being noted. The vehicle will usually be drivable and will not require towing.
What you should do if the Service Engine Soon light illuminates
Light turns on solid:
This means that the OBD II system has detected a malfunction.
Temporary malfunctions may cause your Service Engine Soon light to illuminate. Examples are:
1. The vehicle has run out of fuel. (The engine may misfire or run poorly.)
2. Poor fuel quality or water in the fuel.
3. The fuel cap may not have been properly installed and securely tightened.
Get pdf 1999 Sable Owner’s Manual