Black plate (16,1)Cadillac ATS Owner Manual - 2013 - CRC - 10/5/125-16 Instruments and ControlsMalfunctionIndicator LampA computer system called OBD II(On-Board Diagnostics-SecondGeneration) monitors the operationof the vehicle to ensure emissionsare at acceptable levels, helping tomaintain a clean environment. Themalfunction indicator lamp comeson when the vehicle is placed inService Only Mode, as a check toshow it is working. If it does not,have the vehicle serviced by yourdealer. See Ignition Positions onpage 9‑16.If the malfunction indicator lampcomes on while the engine isrunning, this indicates that theOBD II system has detected aproblem and diagnosis and servicemight be required.Malfunctions often are indicated bythe system before any problem isapparent. Being aware of the lightcan prevent more serious damageto the vehicle. This system alsoassists the service technician incorrectly diagnosing anymalfunction.Notice: If the vehicle iscontinually driven with this lighton, the emission controls mightnot work as well, the vehicle fueleconomy might not be as good,and the engine might not run assmoothly. This could lead tocostly repairs that might not becovered by the vehicle warranty.Notice: Modifications made to theengine, transmission, exhaust,intake, or fuel system of thevehicle or the replacementof the original tires with otherthan those of the same TirePerformance Criteria (TPC) canaffect the vehicle's emissioncontrols and can cause this lightto come on. Modifications tothese systems could lead tocostly repairs not covered by thevehicle warranty. This could alsoresult in a failure to pass arequired Emission Inspection/Maintenance test. SeeAccessories and Modifications onpage 10‑3.This light comes on during amalfunction in one of two ways:Light Flashing: A misfire conditionhas been detected. A misfireincreases vehicle emissions andcould damage the emission controlsystem on the vehicle. Diagnosisand service might be required.To prevent more serious damage tothe vehicle:. Reduce vehicle speed.. Avoid hard accelerations.. Avoid steep uphill grades.
