2010 Ford Mustang Owner's Manual - Page 13

Instrument Cluster Service engine soon: The service engine soon indicator light illuminates when the ignition is first turned to the on position to check the bulb and to indicate whether the vehicle is ready for Inspection/Maintenance (I/M) testing. Normally, the service engine soon light will stay on until the engine is cranked, then turn itself off if no malfunctions are present. However, if after 15 seconds the service engine soon light blinks eight times, it means that the vehicle is not ready for I/M testing. See the Readiness for Inspection/Maintenance (I/M) testing in the Maintenance and Specifications chapter. Solid illumination after the engine is started indicates the On Board Diagnostics System (OBD-II) has detected a malfunction. Refer to On board diagnostics (OBD-II) in the Maintenance and Specifications chapter. If the light is blinking, engine misfire is occurring which could damage your catalytic converter. Drive in a moderate fashion (avoid heavy acceleration and deceleration) and contact your authorized dealer as soon as possible. WARNING: Under engine misfire conditions, excessive exhaust temperatures could damage the catalytic converter, the fuel system, interior floor coverings or other vehicle components, possibly causing a fire. Check fuel fill inlet (if equipped): Illuminates when the fuel fill inlet may not be properly closed. Continued driving with this light on may cause the service engine soon warning light to come on. Refer to Easy Fuel™ "no cap" fuel system in the Maintenance and Specifications chapter. Brake system warning light: To ! P confirm the brake system warning light is functional, it will BRAKE momentarily illuminate when the ignition is turned to the on position when the engine is not running, or in a position between on and start, or by applying the parking brake when the ignition is turned to the on position. If the brake system warning light does not illuminate at this 13