There are a slew of parameters that must be met for it to activate. I think the display will show you why it isn't turning on, on one of the screens. Info:
Refer to pages 166-167 in the 2015 F-150 owners guide/manual.
The system helps reduce fuel consumption by automatically shutting off and restarting the engine while stopped. The engine will restart automatically when you release the brake pedal.
In some situations, your vehicle may restart automatically, for example:
- To maintain interior comfort.
- To recharge the battery.
Note: Power assist steering turns off when the engine is off.
WARNINGs: The engine may restart automatically if required by the system. Switch the ignition off before opening the hood or performing any maintenance. Failure to do so may result in serious injuries due to automatic engine restart.
Always switch the ignition off before leaving your vehicle, as the system may have turned the engine off, but the ignition will still be on and automatic restart may occur.
The Auto StartStop system status is available at a glance within the information display. See Information Displays (page 105).
Enabling Auto StartStop
The system automatically enables every time you start your vehicle if:
- You do not press the Auto StartStop button (not illuminated).
- Your vehicle exceeds an initial speed of 3 mph (4 km/h) after you have initially started your vehicle.
- You have stopped your vehicle.
- Your foot is on the brake pedal.
- The transmission is in drive (D).
- The driver door is closed.
- There is adequate brake vacuum.
- The interior compartment has cooled or warmed to an acceptable level.
- The front windshield defroster is off.
- You have not turned the steering wheel rapidly or you do not have it at a sharp angle.
- The vehicle is not on a steep road grade.
- The battery is within optimal operating conditions (battery state of charge and temperature in range).
- The engine coolant is at operating temperature.
- Elevation is below about 10000 feet (3048 meters).
- Ambient temperature is moderate.
- You have selected 4X2 or Auto mode.
- The trailer is not connected.
- You have not selected Tow haul.
- You have not selected Manual or Sport mode.
Note: The system allows multiple successive Auto StartStop events, but it may not operate in conditions of heavy traffic or in extended low speed operation.
Note: The green Auto StartStop indicator light on the instrument cluster will illuminate to indicate when the automatic engine stop occurs.
Note: If the instrument cluster is equipped with a grey Auto StartStop indicator light, it is illuminated when automatic engine stop is not available due to one of the above noted conditions not being met.
Automatic Engine Restart
Any of the following conditions will result in an automatic restart of the engine:
- You have removed your foot from the brake pedal.
- You press the accelerator pedal.
- You press the accelerator and the brake pedal at the same time.
- The driver safety belt becomes unfastened or the driver door is ajar.
- You have moved the transmission from drive (D) to any gear except park (P).
- Your vehicle is moving.
- The interior compartment does not meet customer comfort when air conditioning or heat is on.
- Fogging of the windows could occur and the air conditioning is on.
- The battery is not within optimal operating conditions.
- You have exceeded the maximum engine off time.
- When you press the Auto StartStop button with the engine automatically stopped.
- The front defroster is turned to the Max setting.
Any of the following conditions may result in an automatic restart of the engine:
- You have increased the blower fan speed or changed the climate control temperature.
- You have an electrical accessory turned on or plugged in.
Note: You may notice that the climate seat fan fluctuates during an automatic restart.
Disabling Auto StartStop
Press the Auto StartStop button located on the center console to switch the system off. The button will illuminate. This will only deactivate the system for the current ignition cycle. Press the button again to restore Auto StartStop function.
Note: If the Shift to P, Restart Engine message appears and the amber Auto StartStop indicator light is flashing, automatic restart is not available. You must restart the vehicle manually. See Information Displays (page 105).
If your vehicle is in an engine off Auto StartStop state and you change the transmission to reverse (R) while the brake pedal is not pressed, the message Auto StartStop Press Brake to Start Engine will appear. You must press the brake pedal within 10 seconds or a shift to park (P) and a manual restart will be required.