Truck won’t start help *fixed*

I have a 2016. The past few days stormed where I live, drove through some pretty deep puddles. Truck ran fine yesterday, today it started dying if I didn’t keep the rpm’s up. Got it home and let it sit for a while. Started it up and it ran fine for a good 10 mins. Went back out to start it up just now and it starts and immediately dies. Try start it up again and nothing, 4lo and 4hi are flashing and there’s the transmission high temp warning. Unplugged the battery and it did the same thing. No codes being thrown. Tried searching and couldn’t find anything. Any suggestions would be appreciated.

edit- transmission high temp isn’t showing anymore, traction is lit up now.

 

How deep is deep? I avoid deep water because the alternator is down low in the engine compartment.

 

Did you get water in the air filter?

 

Maybe a foot deep. Water was splashing and flying everywhere though.

 

No. Checked that and it’s all dry

 

Get battery checked, recharged or swap it for a new one... low and dying batteries do wonky things...

 

Thanks! Will try that tomorrow.

 

You might try jumper battery to confirm before you buy a battery.

 

And don't forget to swap your rear diff oil. Unless you have already done the rear diff breather mod you probably sucked some water in there.

 

Did you check for a hidden CEL? I think some readers can find one even if the light isn’t on.

I’d guess water got in the AIP.

 

Given the background I'd suggest looking deeper into the battery.

After that it is likely water in a connector. I'd start with the speed sensors.

 

How do I check for a hidden cel?

seen that graph, none match up to what I’m reading on my dash. I’m stumped. Gonna try put a jumper on the battery when I get home.

 

Some code readers can do it. I think if you go to an auto parts store, they will check for free, but the truck has to start first to get there. Maybe see if an auto parts store that does loaner tools has one.

 

I tried 2 obd scanners and both had no codes.

 

Now both obd scanners won’t read.

hooked up a battery jumper and no change

 

Damn dude, this sucks. How fast were you going when you hit the water?

 

So your saying that the scan tools say "no communication with the vehicle" ?
If so you need to figure out why. Get ahold of shop manual for your year truck and go through the flow chart diagnosis. You gonna need a dvom

 

20-25mph. My daughter likes flying through puddles, won’t be doing that again. Lol

 

Everything worked intermittently, scanner worked today. Still no codes

 

Problem solved. Looks like it was the hypertech power programmer. Not sure if it’s coincidence it happened after the storm or if it just crapped out. Removed it and all lights on dash are gone and runs like a champ.

 

Glad to hear it!

 

I was just given one by a guy who sold his truck. Was looking up reviews and found this thread.
Seems it has two units that work together. One is mounted in the engine bay, the other is in the driver footwell area.
From where it suggests I mount the engine bay unit it looks like it would get wet from driving through deep water at a fast rate.

Besides this issue, how did it work for you? Worth the trouble to put on?