I have a 2018 XLT that is having an issue restarting. I work about 1 mile from a gas station and first noticed this when I would stop for gas on my way home. I start the truck at work just fine...drive to the gas station and shut it off to pump. Go to restart and it will not turn over. Everything powers up just fine, but it just will not start. When I turn the key to the start position, everything shuts off like normal, but no start. Let off the key and everything comes back. Eventually (few minutes) the truck will start just like nothing happened. I thought it may be because it wasn't up to temp yet, but tried to shut off/ restart when I got home from work (25 minute drive) it is the same deal. If I let it sit for about 10 minutes or so, it starts like normal. Any ideas?

 

Anyone?

 

I would take it by the auto parts store and have them check the battery/alternator out first. If those are ok I would be looking at the starter next.

 

First make sure your battery connections are clean. They can look good but not be clean enough because of an oxide film that is a poor conductor. We need to eliminate that a poor connection first.
When same "no start after warm" happen to me it turned out to be a failing start relay and I would guess there is a 30% chance this is your issue. I am not familiar with newer (2018) model details. Take a look at your owners manual and find the location of your start relay, the relays are generally about 3/4" cubes in the fuse box.

1) Before you start this next sequence take a picture so that you can identify the correct fuse/ fuse slot in case confusion arises. If you can determine the fuses associated with the starting circuit pull them one at a time and inspect and then reinstall. If you do not know what fuses are in the starting circuit pull ALL of them one at a time and inspect and then reinstall. The pulling and reinserting has the effect of refreshing the contact surfaces between the fuse stabs and the fuse box receptacle.
2) Option 1 - Purchase and install a new start relay ( cost around $12-$20)
Option 2 - For the relay you need to identify (mark all the relays and take a picture before you start) the start relay and pull (wiggle) it free then look for corrosion on the stabs, unlikely but this can be an issue. Next pull another relay and compare it with the original start relay, if they are identical then (same number stamped on them) mark them for future reference.
Since your issue is intermitent you need to wait for it to happen again and the swap to two identical relays in a timely fashion and see if the issue goes away. This may take a couple of attempts to pin down the relay as your real issue.
I am sure others will chime in with thoughts concerning solutions to your issue.
Hope this helps!

 

Thanks Jimboy! I will try that.

A little more information to add... I am running a Livewire TS+ tuner and the 93 performance / tow tune from 5 Star.
I am sure the tunes have nothing to do with what is going on, but just to make sure, I have returned to stock for a while.
According to the tuner, while the truck is running, I am at about 14.5 volts, which tells me that the alternator is ok.
When it is having the no-start issue, I am at about 12.1 to 12.3 volts. After trying to start the truck, there is no drop in voltage like if a component is drawing it down.
Steps were:
1.) turn key to "on"
2.) wait for gauges to read
3.) try (unsuccessfully) to start the truck multiple times
4.) turn off the key
5.) wait about 10 seconds go to step 1 and start over

I drove home from work today (20 minutes or so) and stopped to get the mail at the post office. Shut the truck off for about 3 minutes while I was getting the mail and sat in front of the post office for about 10 minutes waiting for the truck to re-start. Frustrating...
It only seems to happen if I shut the truck off for a short time and try to restart. Starts perfectly if it sits for seemingly any time greater than about 20 minutes.

It was not throwing a CEL, but I checked codes right after my original post and it was showing a P0316 Engine misfire Detected on Startup (First 1000 Revolutions) and a P061A Internal Control Module Torque Performance.
I reset the codes and they have not come back since.

 

Anyone got a copy of the starting circuit wiring diagram for 2018 2.7L? If so, please post.

 

Bought a new AGM battery and installed today. Couple if questions....

1.) Could the BMS be causing the no start issue? The way I read things, BMS will shut down things to make sure the starter will still start the truck. I am having the exact opposite of this....

2.) Do I need to go to a dealer for a BMS reset, or does the flash the headlights 5 times and hit the brake pedal three times method work?

 

Which starting system do you have? There are many. Seems more likely that you have some sort of computer problem.

https://www.fordservicecontent.com/F...US_09_2018.pdf

 

Not sure what you mean by starting system. I have an actual key and not a button if that is what you are referring to. Also, I am not getting any messages on the screen.

 

Try the other key, it may be an immobilizer issue.