Accessory Power Timeout

Hi all,

I have a 2018 F-150 and plan to try this upgrade. I have a really silly question, but with all the ‘smarts’ installed nowadays I just wanted to verify this. I have a keyed ignition and with the ignition in ACC will the SYNC system get turned off after a timeout because the truck wants to save the battery? I plan to attach a battery tender so killing the battery won’t be an issue I just don’t want the truck to turn off SYNC during the upgrade. I have NAV so I’m expecting a long upgrade. I would hope with a regular keyed ignition that this wouldn’t happen, like the good 'ol days, but I have to ask.

We recommend keeping it on the 3rd key position (where all the lights come on the dash) I forgot what it was called though lol anyways it will not turn off on that position. For the push button start, there’s an option on the dash to turn off the 30 minute auto shutoff.

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Keep it on a charger, you will need a 10 amp charger. Open and close the door once about halfway thru and it will reset the timers for auto off. You can run the vehicle also, but be sure you do the same as you will have 30 minutes to time out in idle. (For an F-150, anyways.)


Not all vehicles have that available from the IPC…but if you do it’s handy. This can be added with FORScan.

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Thanks all… 10A charger, check and key in 3rd position, check; let’s go with ‘RUN’ (so we have OFF-ACC-RUN-START, how’s that sound? :slight_smile: ).

RUN is the correct position. (Known as Key On Engine Off, or KOEO in the Ford Service Manuals).

Ah, yes, thank you, that knocked some dust off the old brain cells.


Hi guys,

Just an FYI in case anyone else needs this info, the upgrade went smoothly (Thanks Cyanlabs!) but even with the key in the KOEO position the truck tried to shutdown to save battery. I had a charger connected so there wasn’t a low voltage situation it had to be based on time. It happened after the upgrade while I was re-connecting my phone, playing with the setup, making sure everything was working, etc. As I was opening/closing the door periodically to check on the status during the update process I don’t know exactly what the time period to shutdown was but it definitely was going to shutdown even with the key in the KOEO position.

Syn3 Updater says to run the engine, i’m guessing by KOEO your engine was off.

That’s correct, the engine was off, I sorta inferred that running the engine was to keep the system up while the upgrade took place and not to kill the battery. I was expecting a long upgrade since I was upgrading from 3 to 3.4 with nav and really didn’t want to idle the engine that long (chores to do on Saturday :slight_smile: so I wasn’t planning on driving during the upgrade). I have a keyed system and keyed systems usually had key position where it would stay on indefinitely. I started this thread as I was concerned about the truck trying to be too ‘smart’ and shut itself off even with the key in the KOEO position. The direction I got indicated that it would not turn off but that was not the case so I reported back so that anyone else with such a question knows the answer.

I see, yeah it’s known that it will turn off if the engine is not running, not sure why you were informed differently, glad you are all sorted :slight_smile:

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