2WD-4WD mode change malfunction

Thank you sir @BigWhiteTRD i appreciate your help! I’m going to try to get them to pick it up tomorrow. It’s stuck on 4Lo as of now.

 

Does the warranty cover that? My truck is only a few months old..

 

Should, But you never know what the dealer may say you damaged off-roading (which is not covered)... Wash it as well as you can, especially on the undercarriage.

 

Thank you! I will.

 

Did you go over deep water during off-roading?

 

yeah their was water...

 

Might have shortened the actuator. It might start working again after drying if nothing fried.

You might also want to change diff fluids unless you have a breather, water can get into them pretty easily if submerged. I don’t know if that is also an issue with tcase, someone else can chime in on that.

 

Thank you so much! I’ll keep all those in mind!

 

There is about a 99% chance that the vent (rubber tube) is off of the front ADD actuator.
(stolen picture from a 4 runner or something, but it looks the same to me)


Water can enters the actuator thru the vent line if is broken or pulled off. If it enters the actuator, the ECU will see the leakage current to ground for the actuator motor circuit.

Actuator almost certainly will need to be removed if the vent is compromised, If it has corroded it will need to be replaced. The front diff oil should be replaced too (if the vent line is compromised.)

 

Agree with others. Based on what causes most problems with this system, 99% chance the ADD actuator on the front axle hates life.

 

Good morning , so I turned on my truck this morning and it’s back on 2WD!!! The 4L and the hazard light are no longer on!

 

I get the feeling you’re just twisting knobs. So you parked it with the selector switch in 2HI and it shifted from 4LO to 2HI while you slept?

 

Yes sir!

 

That’s impossible lol. It must have already been in 2HI but the switch inside the transfer case wasn’t reporting that.

You can feel the difference between low range and high range right?

 

OP, did you try to go from 4 LO to 2wd right away? Bypassing 4 HI?

 

Yeah I felt the difference

 

So my truck was flashing 4LO last night while being on 2WD, but I woke up this morning with no flashing lights on dash board.

 

Probably a sensor got wet and stopped working, and the started working again after drying. I dont know where the position sensor for 2/4wd or 4wd-low is, but if it is inside the diff or the tcase, that indicates water got in. I would make sure the fluid is water-free. Also make sure the sensor and the actuator are dry, otherwise they can corrode.

 

So there is about Zero chance the problem is gone for good. And the freeze frame data is stored in the ECU for the dealer to investigate... you definitely want the issue recorded (when its convenient)...

The truck will try to change to the current dial setting when you turn on the ignition... if the root issue (maybe water shorting the add motor) was no longer there, the truck will successfully shift into the appropriate mode.

Make no mistake, this is almost certainly the truck's ECU failsafe trying to protect the truck... So the root cause of the ECU check will return...

 

And add a diff breather mod