FORD 2014 E-450 v.1 - Manual (Page 201)

What You Should Know About Fail-Safe Cooling
If the engine coolant supply is depleted, this feature allows the vehicle to
be driven temporarily before incremental component damage is incurred.
The fail-safe distance depends on ambient temperatures, vehicle load and
terrain.
How Fail-Safe Cooling Works
If the engine begins to overheat, the engine coolant temperature gauge
will move to the red (hot) area and:
The coolant temperature warning light will illuminate.
The service engine soon indicator will illuminate.
If the engine reaches a preset over-temperature condition, the engine
will automatically switch to alternating cylinder operation. Each disabled
cylinder acts as an air pump and cools the engine.
When this occurs the vehicle will still operate. However:
• The engine power will be limited.
• The air conditioning system will be disabled.
Continued operation will increase the engine temperature and the engine
will completely shut down, causing steering and braking effort to increase.
Once the engine temperature cools, the engine can be restarted. Take
your vehicle to an authorized dealer as soon as possible to minimize
engine damage.
When Fail-Safe Mode is Activated
WARNING: Fail-safe mode is for use during emergencies only.
Operate the vehicle in fail-safe mode only as long as necessary to
bring the vehicle to rest in a safe location and seek immediate repairs.
When in fail-safe mode, the vehicle will have limited power, will not be
able to maintain high-speed operation, and may completely shut down
without warning, potentially losing engine power, power steering assist,
and power brake assist, which may increase the possibility of a crash
resulting in serious injury.
200 Maintenance
2014 Econoline (eco)
Owners Guide gf, 1st Printing, November 2012
USA (fus)