Glad to hear it worked. I suspect that inserting the key powers the dash, so you need to hit "OK" button before inserting the key. At least that's the way my truck seems to work with trying to enter this mode.

 

I know it works on most new Ford vehicles, however; the procedures may differ. I have an 06 Fusion that cannot do this although most other Ford vehicles of the same model year can. I'm sure there are a few (the hybrids?) that can't.

 

So does that same procedure work on 2011+ Super Duty's?

 

This video shows him using other buttons. Maybe there are different key combos to enable test mode?

 

Those who can access the dash engineering mode can diagnois 90% of all battery charging system issues.
Step to the digital voltmeter in the display. Do not pay attention to any other battery display.
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FOR original AGM battery equippage.
A. At rest after setting 8 hours, the AGM voltage should be close to 12.3 volts. Note: this voltage range is NOT at 100% full charge level (by intent and design).
B. When cranking, the voltage will flutter fast but show the starter loading during cranking. It should not go below 10 volts by more tha a tenth on a good battery.
C. After the motor starts and runs about 2 minutes, the voltage should be about 14.6 +/- .1 volts.
Note the digital voltmeter only reads to the nearest tenth of a volt and rounds either up or down, which is no problem.
The above is based on battery in good condition and a fault free charge and control system.
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For A.; the voltage is the state of battery charge (SOC) after about 8 hours rest with the egine off, all doors closed and locked. The sytem uses this refernce as a parameter.
For B; the cranking voltage drop is due to the normal high current being drawn by the starter under load turning the motor over and will be unstable..
For C; the charge voltage applied to the battery to recover the charge. The truck will stay at this voltage as long as it runs to both recharge and run the vehicle systems and is temperature sensitive to a small degree (battery temp.) and lewnth of cranking time..
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All the above depnds on
1. The battery state of health.
2. The temperature of the battery, especially in winter..
3. Alternator output.
4. Battery cable connections, cleanlyness and tightness or any combination of the above.
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These are my reading based on the difference between an aged battery and a new Motorcraft of the same size in a trouble free 2018 5L system..
Cranking becomes very much faster than the old battery..
If you see any of the voltages too far away from the above and experience an issue, decide what the issue most likely will be based on what the voltages are in the three parts of the sequence.
For more info, do search request for ..General Bullitin II.. on battery charging and maintaince, a Ford document.
In this Doc you will see the SOC range % and max charging voltage (AGM). Charge voltage levels are diffewrewnt between an AGM and a Lead Acid type batteries.
One battery should not be subbed for the other without a program change in the BMS program and a reset done in the BMS. This cannot be done correctly by just removing a battery cable for any amount ot time.
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Low state of charge can be insufficient time for recharge after the last time the vehicle was driven, battery age/condition, low Alternator put put etc..
Al these will be reflected in the values observed above
They are especially critical to Stop/Start operation..
Good luck.