2018 OffRoad 4hi flashing

I was doing some very light wheeling… put it 4lo/rear locker/crawl control just to exercise everything up a gravel hill. Once atop the hill, switched to 4hi without issue. Before I returned to pavement, switched to 2hi. It physically switched, but… the 4hi indicator continues to flash. It will not go back into 4hi either.

 

In case you did not controllably and intentionally try this in your attempts ... switch to neutral, then change into or out of 4hi, then into drive. While you can in theory change to/from 4hi in motion, this "reset method" can make it rethink.

 

Thanks. And yes, tried it. Also, disconnected battery for a couple of hours and tried again. Checked wires at transfer case as well.

 

Completely flat spot seems to help. MT transmission here....sometimes a roll back, roll forward, stop clutch in, jiggle the stick, reverse, back to first....eventually one of those seems to get it....but flat land helps the most. Any incline or tilt to the road and it gets tricky.

 

If it is no longer binding as if it’s in 2WD (based on your description that it shifted), it probably only shifted either the ADD or t-case, but failed on one of them. If either of them are in 2WD mode, then you will be in 2WD. They both have to be engaged to achieve 4WD.

So, first step is to get under the truck and try to turn the front driveshaft. If it turns freely, then you have some sort of electrical/reporting problem. If the driveshaft is locked, then the truck is correct about flashing the light and you then have to figure out if it’s either the ADD that didn’t shift or the t-case.

 

Thanks everyone. It ended up being the 4wd actuator, which had water in it. Found the same exact issue on YouTube.

 

I was going to suggest maybe that solenoid got full of water, good you figured it out. Curious, did you do any water crossings? If so, how long ago?

 

Yeah, went swimming two summers ago High centered, over an inch of water in the floorboard. Good news, Warn winch worked underwater. Anyway, 4wd has been working ever since, until now. The actuator is supposed to be sealed. So for future adventures, it now has rtv as well as the gasket. Maybe it will be waterproof now instead of water resistant.

 

Good move! I don't off road much, and damn sure avoid water crossings. But, if or when I need to replace mine, the new one will get the sealant treatment beforehand.