Ford 2009 Mustang Owner's Manual page 11

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 have your vehicle serviced
immediately by your authorized dealer.
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 cap (if equipped):
Illuminates when the fuel cap may
not be properly installed. Continued
driving with this light on may cause
the Service engine soon warning
light to come on. Refer to Fuel
filler cap in the Maintenance and Specifications chapter.
Brake system warning light: To
confirm the brake system warning
light is functional, it will
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
time, seek service immediately from your authorized dealer. Illumination
after releasing the parking brake indicates low brake fluid level and the
brake system should be inspected immediately by your authorized dealer.
2009 05+ Mustang (197)
Owners Guide
USA (fus)
Instrument Cluster
! P
BRAKE
11