4 hi works fine. 4 low not working, no 4x4 low light, new 4x4 motor and vacuum solenoid, I can manually move the transfer case in low with a wrench. Old and now new motor doesn’t move enough to engage the low position. In neutral and foot on brake. Honestly I can’t remember when the low part went out. The high gets used all the time.
help!
thanks,

tested the selector switch. #2-#3 pin had 600,270,130 ohms. 2h, 4h,4l.

 

A worn shift fork would be my first guess
Most malfunctions with the 4 low involve being stuck in 4 low
That also happens when the shift fork wears out
If the motor is moving when you command 4 low but is not moving far enough, the fork is the problem IMO
Tear down and inspect the transfer case

 

Thanks!
I marked the new motor with a sharpie with the truck off the ground at 2wd and 4h but it just doesn’t move other than these two spots. With the truck off the ground, in neutral and the TCM off I can manually turn the TC into all 3 positions.somethings not telling the motor to rotate to that position. I have a new vacuum solenoid installed, but that didn’t work.

 

Are you shifting into 4LO at the proper point? If I remember correctly, it needs to be done in neutral, and it helps if you are slightly moving. I’m guessing some condition isn’t satisfied, and the computer won’t let it shift.

 

That is what I am thinking then, the truck does not see neutral or the limit switches in the motor are not recognizing where they are at
That motor needs to go from 4 hi into neutral and then into 4 low, it needs to know each position, or the processor will not let it shift
Low is a safety issue and so shifting into low is where ALL the parameters must be met
I swear some used to have to have the E brake applied
Try that just in case
I looked yours up, (well, I looked up a 04 I think) yours should just need to be in neutral
Maybe the module is not seeing neutral
What year is it? Better grab a service manual

 

Thanks,
also abs pump runs continuously. I took the fuse out, like a year ago. The brake and abs light stays on of course.
Do you think these two systems are intertwined causing 4low problems?
I did insert the abs fuse, turn selector switch to 4low, neutral, brake and hear a clunk from under the truck, but still no 4low light or 4low gear. It is in a gear because a can drive it. Did this several times, then unplugged the fuse again.
Also found a random vacuum hose that’s disconnected from something. Under the air filter housing, close to the abs pump. Maybe 1/8” black. Can’t find where the end goes. Looks like the other end goes to the drivers side wheel.

good grief!

 

There are vacuum lines that go to the IWE actuators at the hub, that might be what you're looking at. That shouldn't effect the transfer case shifting because there is no feedback for whether the hubs are locked or not. There is also an open tube for the venting on the actuators as well.

If the systems were on the same fuse, having it out would make it so nothing on either system work. I still think you have an issue with input on the drive train system. I do know there is a delay on mine when switching to 4LO, making sure it is in neutral. You could have an issue with your range indicator/neutral safety.



Here's what my live data looks like. Neutral indicated only in neutral, not park. It will not shift from HI to LO in anything but neutral, but 4HI to 2HI and back is available any time.

I would recommend buying or borrowing one of these readers. This one was about $99 like 4 years ago, and it's been a godsend.

 

Would this be a Vehicle Communication Module they refer to in the diagnostic repair download?

 

That's the dealership diagnostic module they use, with their laptop and software that's quite expensive. I've got a Launch CRP123, it was $99 on special from Amazon years ago. It's more than paid for itself.

 

Yes, I’m thinking of getting one. It’s almost impossible to diagnose vehicles now without it. I think they went up to like $130-$150.