OBD port FORD F250 SUPER DUTY 1999 Owners Manual

What you should do if the Check Engine/Service Engine Soon light
illuminates
Light turns on solid:
This means that the OBD I system has detected a malfunction.
Temporary malfunctions may cause yourService Engine Soonlight 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.
These and other temporary malfunctions can be corrected by filling the
fuel tank with good quality fuel. After three driving cycles without these
or any other temporary malfunctions present, theCheck Engine/Service
Engine Soonlight should turn off. (A driving cycle consists of a cold
engine startup followed by mixed city/highway driving.) No additional
vehicle service is required.
If theCheck Engine/Service Engine Soonlight remains on, have your
vehicle serviced at the first available opportunity.
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.
Service engine soon (California only)
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.
TheService Engine Soonindicator 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.
SERVICE
ENGINE
SOON
Instrumentation
9

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 yourService Engine Soonlight 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.
These temporary malfunctions can be corrected by filling the fuel tank
with good quality fuel and/or properly installing and securely tightening
the gas cap. After three driving cycles without these or any other
temporary malfunctions present, theService Engine Soonlight should
turn off. (A driving cycle consists of a cold engine startup followed by
mixed city/highway driving.) No additional vehicle service is required.
If theService Engine Soonlight remains on, have your vehicle serviced
at the first available opportunity.
Light is blinking:
Engine misfire is occurring which could damage your catalytic converter.
You should drive in a moderate fashion (avoid heavy acceleration and
deceleration) and have your vehicle serviced at the first available
opportunity.
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.
Air bag readiness
Momentarily illuminates when the
ignition is turned ON. If the light
fails to illuminate, continues to flash
or remains on, have the system
serviced immediately.
Instrumentation
10