Solved - 4hi Light blinking, won't "disengage" 4hi and 4low work fine

@jberry813 Any thoughts from the expert?

 

Not sure. Never had this problem before. From my brief readings seems like many variables involved.

So you unplugged the 4lo? Can you unplug the 4hi? Not sure what this stuff looks like. Where are these sensors? Behind the buttons in dash?

 

they are actuator sensors down on the transfer case. one tells if it's in 4low or not, and one tells it if its in 4hi or not. I accidentally unplugged the 4low one instead of the 4hi one because I think the 4hi one is bad, but I'm not sure.

before today I could engage and disengage my 4hi and 4low with no problems, other than the blinking 4hi light all the time.

 

my 2011 tundra crewmax had a similar problem, I was able to drive but the RPM's were crazy high , it was the 2 knock sensors. rats had chewed through the wires.

 

well, I tried it with both sensors unplugged, and still nothing. At this point I'm thinking something got screwed up with the actuator. why, I don't know, but it won't shift at all. no sounds, no motor noise, nothing.

 

Yeah buddy. I read this problem you posted the other day. Can you unplug both? Then plug back in. Maybe its a sequence hook up.

 

tried that. nothing.

 

When you opened the actuator you said it looked good and clean. Did anything fall out. Some of the readings some people said they opened up and spring fell out.

 

nope. it was all there to my knowledge. I didn't even take the big gear out. it was completely dry and lubricated.

 

Sounding like a switch or wiring situation. Everything mechanically is working. Something is not talking to the right thing.

 

that's what I'm thinking. is there a way to reset the transfer case control module? I'm researching that now.

 

Not sure bud. Let us know what you find out. Might happen to one of us in the future. Haven’t read or heard of this problem before.

 

Thank you! I’ll PM you.

And I do not have a techstream. Actually I’ve never heard of that before. I’ll look into it.

 

Cool! I'll pick one up! is this one the one to get, or is it like cheap OBD2 dongles and they're all pretty much the same?

 

gotcha. I am a Mac guy, although I'm an IT major in school, so I'm fairly tech savvy. Thanks so much for your help!

 

that's funny! great to find someone with a common background (sort of). placed the order for the cable. thanks for your help!

 

Finally got the Techstream and plugged in and ran in my truck. The good news is, I solved the airbag light and the cruise control issue. The clockspring is bad.

The bad news is, no info on the 4x4 system.

Code for the clock spring,
Code for low voltage in the + battery terminal,
Code for open Stop signal.

Any help?

 

Whats up with the ABS/VSC/TRAC? I wonder if that could cause It.

 

That’s the open stop circuit and low voltage + terminal codes.

 

Maybe it sounds counterproductive but you should fix that clock spring and see if that helps. Today’s technical features of these trucks can make one small problem, A big one. Just a thought

 

Wouldn't that abs/vsc/trac be a bad wheel speed sensor or abs ring?

 

Not based on the code.

 

Update:

I got it out of 4low! I did the old bank on the actuator with a hammer truck, and it’s back to where it was before. I think I jammed it up when it got confused about the 4low sensor.


Now it’s back to where it was before. Engages and disengages, but 4hi light blinks.

I’m thinking now that it’s the ADD actuator on the front diff because I can’t hear it engage or disengage with the rear actuator.

 

Nice. So the T-case works, but the axle isn't engaging?

 

disengaging rather.

I did some further exploration, and I seem to feel/ hear the front actuator moving too, so I'm back to the original sensor theory.

 

looks like the sensor wasn't the problem. Now I'm back to the ADD actuator. I've tapped it with a hammer and I can't get it to go. blech.