Cooling System: Description and Operation
Engine Cooling
NOTICE: The engine cooling system is filled with Motorcraft(R) Specialty Orange Engine Coolant. Mixing coolant types degrades the corrosion protection of Motorcraft(R) Specialty Orange Engine Coolant. Do not mix coolant types. Failure to follow this instruction may result in engine or cooling system damage.
NOTICE: Stop-leak style pellets/products must not be used as an additive in this engine cooling system. The addition of stop-leak style pellets/products can clog or damage the cooling system resulting in degraded cooling system performance and/or failure.
NOTE: The addition of Cooling System Stop Leak Pellets darkens the coolant.
The cooling system consists of the:
- radiator.
- cooling fan motor and shroud.
- degas bottle.
- radiator drain valve.
- coolant pump.
- thermostat housing.
- block heater (if equipped).
Engine coolant provides freeze protection, boil protection, cooling efficiency and corrosion protection to the engine and cooling components. In order to obtain these protections, the engine coolant must be maintained at the correct concentration and fluid level in the degas bottle.
When adding engine coolant, use a 50/50 mixture of engine coolant and distilled water.
To maintain the integrity of the coolant and the cooling system:
- Add Motorcraft(R) Specialty Orange Engine Coolant. Mixing coolant types degrades the corrosion protection of the original coolant. Do not mix coolant types.
- Do not add alcohol, methanol, brine or any engine coolants mixed with alcohol or methanol antifreeze. These can cause engine damage from overheating or freezing.
- Ford Motor Company does NOT recommend the use of recycled engine coolant in vehicles.
Fail-Safe Cooling
The vehicle has a strategy built into the PCM that will control the engine if it starts to overheat.
Stage 1 of the strategy will commence if the engine starts to overheat. The Cylinder Head Temperature (CHT) sensor transmits a signal to the PCM, which then moves the temperature gauge pointer into the red zone.
If the engine is not switched off and the temperature continues to rise, the Powertrain Check Lamp is illuminated. This indicates to the driver that the engine is approaching critical limits and should be stopped. At this point DTC P1285 is set in the PCM which can be retrieved using a scan tool.
Stage 2 of the strategy will commence if the lamp and temperature gauge are ignored by the driver. The PCM will start to control the engine by cutting out 2 cylinders and restricting the rpm to below 3,000 rpm. Simultaneously the Malfunction Indicator Lamp (MIL) will be illuminated. This indicates that long term engine damage can occur and vehicle emissions will be affected. At this point DTC P1299 is set in the PCM which can be retrieved using a scan tool.
Air is then drawn into the deactivated cylinders. This helps to control the temperature of the engine internal components. The deactivated cylinders are alternated to allow even cooling of all the cylinders.
NOTE: If the driver is using a high percentage of throttle travel (for example, an overtaking maneuver) when the PCM starts engine deactivation (Stage 2), the deactivation will be delayed for 10 seconds.
NOTE: After 2-cylinder operation has begun, the engine will not revert to 4-cylinder operation, even if the temperature should fall, until the ignition is switched off and then on again.
NOTE: The MIL can only be extinguished by using a scan tool after the fault has been rectified and the DTC cleared.
Stage 3 of the strategy will commence if the engine temperature still continues to rise. This will result in the engine being totally disabled before major engine damage or seizure occurs. The Powertrain Check Lamp will begin to flash, indicating to the driver that the engine will be switched off after 30 seconds. This allows the driver time to choose a suitable parking place.
Coolant Flow Diagram
NOTE: Black arrows indicate hot, white arrows indicate cold.
