The truck is a 2016 5L Supercrew 4x4 107k. Lastnight driving home about 25 miles mostly interstate in moderate rain (wipers on low, good visibility, no standing water). We drive home running 60-65 mph most of the way when we get off at the exit to our area the wrench light comes on. Truck idling fine no odd behavior turn the radio down a pay attention type moment. We drive for another 1.5 miles on paved city street to our home roll in the drive way to my spot and before I could put it in park the truck just dies 1st thing I noticed was the charge light but that was just a side effect of the engine being off I presumed at the time.

Truck would crank without starting and continued cranking even when I let the key roll back to on. Stopped cranking when turned key to off position. Turned key back to on position all appropriate warning indicators come on. I got the wrench light not the check engine light I just wanted to see if it was operational in addition to the other indicators trying narrow the issue down.

After letting the truck sit for 5 minutes I push the remote start button on the key fob and it starts right up no issue. I walk back out to the truck unlock the door get in and put the key in the ignition turn it to run and the engine dies. So now it's fishy it'll run on remote but not normal. And with the key once it starts cranking out continues to crank until the key is turned back to off.

This morning I go out put the key in and it fired right up no light no issue just like normal. Plugged my scanner in, no new DTC's did a all module scan nothing current.

No visible water intrusion in the footwells or under the hood up near the cowl area and fuse box. I'm at a loss as to what's lurking. The truck hasn't given me any real issues to date.

it did have some module codes that weren't current the last code when I searched indicated I should have turn the HVAC off before the test maybe.

 

Do you keep your fob separate from your key chain/ring, or do you have a pound or two of keys hanging off of it?

 

That all there is. These new keys are to big to put on a ring with anything else.

 

The reason I asked is because the weight of a key ring will wear out the ignition switch. Then contact is off and on for some of the ignition controlled modules. That could still be your problem though. Next time it happens, jiggle the key and see what happens.

Another thing it could be is water dipping on the modules on the passenger side of the firewall. The PCM, TCM, Airbag, and transfer case modules are there. If you had it in for service, and someone didn’t close the lock lever, that would be the likely spot. Or, you may have had the vacuum pump replaced, or some other work done in that area and one of the harnesses got damaged.

 

I figured that's what you were thinking about the keys I'll have to see in the huddling thing.

I drove this evening and it didn't do anything wrong.

Hasn't been in for any service work. I don't trust anyone to work on my ride. I tried to start it a couple times last night. I had pulled it up to close to a bush to work on it not knowing it was going to die out. I managed to get it started with the remote start and put the key in and feather the gas long enough to get it backed up to a more accessible area for working on it. Oddly enough it didn't have any symptoms this morning.

 

Electrical problems can be frustrating. And when one unexpectedly goes away, you're always waiting for it to return at any minute.

 

Problem never has repeated, drove in rain for several hours on the way to the coast. It's been through several rain storms since. No clue as to what happened that night.