FORD 2011 F-550 v.2 - Manual (Page 378)

When fail-safe mode is activated
You have limited engine power when in the fail-safe mode, so drive the
vehicle with caution. The vehicle will not be able to maintain high-speed
operation and the engine will run rough. Remember that the engine is
capable of completely shutting down automatically to prevent engine
damage; therefore:
1. Pull off the road as soon as safely possible and turn off the engine.
2. Arrange for the vehicle to be taken to a service facility.
3. If this is not possible, wait a short period for the engine to cool.
4. Check the coolant level and replenish if low.
WARNING: Never remove the coolant reservoir cap while the
engine is running or hot.
5. Re-start the engine and take your vehicle to a service facility.
Driving the vehicle without repairing the engine problem
increases the chance of engine damage. Take your vehicle to a
service facility as soon as possible.
Engine fluid temperature management (except 6.8L V10)
Your vehicle has been designed to pull a trailer, but because of the added
load, the vehicle’s engine may temporarily reach higher temperatures
during severe operating conditions such as ascending a long or steep
grade while pulling a trailer in hot ambient temperatures.
At this time, you may notice your engine coolant temperature gauge
needle move toward the H and the POWER REDUCED TO LOWER
TEMP message may appear on the message center.
You may notice a reduction in the vehicle’s speed caused by reduced
engine power. Your vehicle has been designed to enter this mode if
certain high temperature/high load conditions take place in order to
manage the engine’s fluid temperatures. The amount of speed reduction
will depend on the vehicle loading, towing, grade, ambient temperature,
and other factors. If this occurs, there is no need to pull off the road.
The vehicle can continue to be driven while this message is active.
WARNING: To reduce the risk of collision and injury, be
prepared that the vehicle speed may reduce and the vehicle may
not be able to accelerate with full power until the fluid temperatures
reduce.
Maintenance and Specifications
378
2011 F-250/350/450/550 (f23)
Owners Guide, 2nd Printing
USA (fus)