Auto Start-Stop not consistent

[Salwans]

Any one else notice inconsistent Auto Stop-Start behavior on their EB?

On most trips, my Auto Start-Stop appropriately kicks in. On occasion however, it doesn’t kick in even when I haven’t turned on the A/C. I initially attributed it to the low winter temperatures (in the 30-40’s) requiring the engine to warm up, but now we’re in 80-100 degree weather and it still doesn’t kick in some of the time. Anyone else see the same behavior? Any thoughts on why?

Sponsored

 

[Platinum2]

I recall the OM describing certain scenarios that can cause this, but I don't remember specifically what they are. It is normal.

 

[kcamp317]

If there's a large demand for the A/C (in hot weather) many times the start/stop system is temporarily disabled by the computers to keep up.

 

[The Weatherman]

What kcamp317 said. Plus the battery charging level will effect how the start/stop engages.

 

[Trucklet]

I know it's a totally different vehicle, but I recently bought a Chrysler with Auto Start/Stop and there's a laundry list of criteria it constantly checks to see if it's appropriate to cut the engine. I'm not sure how many of these Ford also uses, but a few examples:
If the engine isn't up to operating temp
If the climate control is still working to get to set temperature
If you're stopped on an uphill incline greater than some amount
If your front wheels are turns greater than some amount (often prevents activation in drive-thru)
If you stopped just moments prior (stop and go traffic)
If battery isn't topped off
If your seatbelt isn't buckled
If it doesn't like the cut of your jib.

If interested, the Maverick has a screen on the instrument cluster screen that shows you the status of the start/stop logic. That's how I learned all of these reasons on the Chrysler, anyway. It'll tell you "why" it's not activating and eventually you figure it out (and stop caring, haha).

 

[KevCuRaoi]

Any one else notice inconsistent Auto Stop-Start behavior on their EB?

On most trips, my Auto Start-Stop appropriately kicks in. On occasion however, it doesn’t kick in even when I haven’t turned on the A/C. I initially attributed it to the low winter temperatures (in the 30-40’s) requiring the engine to warm up, but now we’re in 80-100 degree weather and it still doesn’t kick in some of the time. Anyone else see the same behavior? Any thoughts on why?

It is normal. Are you on a hill? Steering wheel turned?

Numerous factors are checked before the engine shuts off. For Ford GSB about auto start-stop operation:


Typical Auto Start-Stop System Inputs (Input From Other Vehicle Systems)

• Vehicle speed is 0 kph (0 mph)
• Accelerator pedal is released.
• Brake pedal is applied
- Brake on/off switch activated (indicates ON)

• Clutch pedal cruise control deactivator switch indicates the clutch pedal is released. Clutch pedal in full TOP position of travel. (manual transmission only)
• Brake system pressure is approximately 482 kPa (70 psi) or greater
• ABS is not active
• Brake booster vacuum is present and a vacuum change does not occur while the vehicle is stopped
• Gear selector lever in ‘N’ neutral for manual transmissions and ‘D’ drive for auto transmissions
• Battery temperature is between 5° C (41° F) to 60° C (140° F)
• A/C system is OFF, or there is no change in the A/C system request while the vehicle is stopped
• If the A/C system is ON, ambient temperature should be less than 35° C (95° F)
• Road grade while stopped is less than 15%
• All doors remain closed and the occupied front seats have the seat belt latched.
• The 110v alternating current inverter (if equipped) is under 10w electrical load and the electrical load does not change while stopped
• Trailer harness is not connected
• Tow/haul mode is not active
• 4WD (if equipped) is in the 2WD position and does not change while stopped
• Electronic locking differential (ELD), if equipped, is not engaged
• In-car temperature is steady and no change is requested from the heating or A/C system
• Engine coolant temperature is at the normal operating temperature
• Max A/C or defrost is not selected
• Blower fan control is at one speed setting and a speed change request does not occur while the vehicle is stopped
• Rear defrost is not selected and a rear defrost request does not occur while the vehicle is stopped
• Battery and charging system voltage is greater than 11.3 volts
• Electrical load is less than 65 amps and a voltage or amperage load change does not occur while the vehicle is stopped
• Steering wheel angle is less than 90° from the center position and a steering input change does not occur while the vehicle is stopped
• Hill start assist is not active
• Automatic transmission fluid temperature is less than 110° C (230° F)
• Fuel level is greater than 1/8 full and the low fuel warning is not active
• Auto start-stop system restarts are limited to 10, unless the vehicle speed exceeds 4 km/h (2.5 mph)
• Auto start-stop functionality operates independently only from vehicles equipped with electronic brake boost (EBB)

Sponsored