Trouble with 4 wheel drive

I noticed after purchasing the truck and trying to go into 4wd it would not go in after leaving it on the 4hi selector and turning the vehicle on and off it would go in fine, same thing to get it back into 2wd. When the key is in the on position but vehicle is not running it will go in and out fine. Any ideas what this might be?

 

Was it flashing? Sometimes you just need to move forward a little or backup a little, slowly. Occasionally turning the wheels helps too (slightly not hard).

 

Yes light flashes, I have tried park, neutral, drive, and driving at a slow speed. I’ve left it for a few mins flashing waiting to see if it would switch over and still nothing.

 

Got it, hmm that does indicate an issue then, may be a sensor or the actual actuator has an issue, others will know more.

 

When it's in 4 Hi, with the truck running and stopped, if you shift to neutral and put it in 4 Lo, then shift to drive and start moving forward, does it shift into 4 Lo?

 

Any issue with speed sensors?

Does the cruise control work?

 

Haven’t tried the 4lo will try that tomorrow. And speed sensors seem to be spot on no issue with cruise control.

 

More info that might be helpful. https://www.tundras.com/threads/2007-2020-transfer-case-actuator.61182/