Need help with service 4 wheel drive

racerx520 · February 12, 2021

Hey everyone, I know this is a question asked a lot but I can't get to the bottom of my issue and I'm looking for help. I saw the videos of the ground wires on the body mount under the driver's side door, but I only have 1, yet I still cleaned it up with no improvement. I do not own a tech 2, so I brought my truck to a shop and they got a code c0306 for the transfer case motor.
Before this....I replaced the actuator (new), transfer case motor (used), transfer case module (used) and the 4x4 switch (new). After the diagnosis I put in a new transfer case motor and put the original module back. The truck still had a constant message of service 4 wheel drive.

This is where it gets odd to me...I was convinced this was an electrical issue so I put dielectric grease on the actuator, transfer case motor, and transfer case selector connectors. I also changed out the trans fluid and found some metal dusting on the magnetic drain plug.

NOW I don't get the message upon start up, but if I drive a little bit it will come up. But if I shut the truck down for longer than 2 mins (seriously I turned it off at a traffic light) then the message goes away.

I feel like I'm still chasing an electrical issue, but I don't want to pay a shop when I'm this deep in it. Any help is appreciated!

Sharpz · February 12, 2021

What you need to make sure of is that you have a good ground all the way to the actuator, and to the shift motor. Jumping in a ground might be the way to go if not. It doesnt mean this is your problem, but once eliminated you can move on. Your issue to me does sound electrical so if you have an ohms meter, check what you are getting at these two plugs, and then at your switch also while engaging/disengaging. If these test good, then try disconnecting your battery for about 10 minutes and see if this problem goes away. The other thing is have you tested if this truck is going in an out of 4 wheel drive? Can you hear the motor engage?

racerx520 · February 20, 2021

I had the truck at a local shop with a reputable mechanic. Long story short, after having it for 2 days he said he found a loose pin connector nowhere near the transfer case but part of a larger connector (wouldn't specify into what system) and tightened it. I haven't had an issue yet.