I think I'm stuck in AWD

[RockStarr1]

I think that I'm stuck in AWD. A week or so ago I started noticing that I was getting worse gas milage than usual, eventually I determined I was in AWD. There is no "service 4WD" light on my dash, but the amber colored lights on my ATC only come on with ignition...sometimes. When I try to shift to ANYTHING, nothing happens, no noise, nothin'. I've read some of the posts on this, and I tried the 8 fuse and all that did was make the "service 4WD" light come on, on my dash. So my Quetion is...Is the next step to go get the module reprogrammed? If so, how much should that cost? Thanks

[RayVoy]

Not sure how u determined how u are stuck in AWD. But if u are, the front axle shafts should be fully engaged, and they would turn the front drive shaft. So, a quick way to test this is to see if ur front drive shaft is turning. Crawl under and mark the frt drive shaft, move the truck a few feet, look at ur mark to see if it moved.
This, of course, only gives us a starting point, but we would at least know if ur stuck in awd.

[RockStarr1]

I swear it was doing everything i described. The last thing I did before I posted the thread was mess with the 8 fuse and the light on the dash came ON. Now I go back out to make sure I'm stuck in AWD and everything is fine, I'm in 2hi, no lights on the dash, but the ATC lights are working, suction sound when i shift and everything. It has been doing this for at least a week or so. Fidgety little things aren't they. thanks

[RayVoy]

Hey, these things seem to need a reboot every once in awhile. A lot of guys have fixed numerous problems by disconnecting the bat for 10 mins. Seems to reset all of the computs.

Ray

[njVoyXL03]

Not sure how u determined how u are stuck in AWD. But if u are, the front axle shafts should be fully engaged, and they would turn the front drive shaft. So, a quick way to test this is to see if ur front drive shaft is turning. Crawl under and mark the frt drive shaft, move the truck a few feet, look at ur mark to see if it moved.
This, of course, only gives us a starting point, but we would at least know if ur stuck in awd.

Or you can dig a ditch and tell one of ur buddies to drive over you and you watch which axle moves and which don't
:thumbsup: :undecided :m2:

[RayVoy]

Or you can dig a ditch and tell one of ur buddies to drive over you and you watch which axle moves and which don't
:thumbsup: :undecided :m2:

I like it, or,, u could try the "Speed" method. Get on a dolly, tied under the truck while ur buddy drives above 50 mph:laugh: :laugh:

[hatchet669]

I like it, or,, u could try the "Speed" method. Get on a dolly, tied under the truck while ur buddy drives above 50 mph:laugh: :laugh:

i think the easiest and safest way would be to find a gravel lot and just floor the pedal... but i like ur idea makes it more fun

[jaylind]

While reading the last few posts I seem to keep hearing music from Indiana Jones..(flash back to the first movie as he used his whip to slip under the truck while moving)

JAy

[RayVoy]

While reading the last few posts I seem to keep hearing music from Indiana Jones..(flash back to the first movie as he used his whip to slip under the truck while moving)

JAy

We'll do anything to fix a broken truck, but I don't have a whip.:dielaugh:

[Dave]

If it was stuck in A4WD then your vehicle would be vibrating like crazy when turning on dry pavement (part-time systems don't like to be activated on dry roads). That is probably the safest way to find out if it is stuck in A4WD. Drive it too long in the dry with an active front axle and you'll just be stuck.

[HappyCamper]

My 2002 LS has the auto trac awd system. I don't know if this changed in the later years or not but the front wheels do not receive power until the rear wheels spin. Therefore all previously mentioned methods in this thread would work fine for checking if the vehicle was stuck in 4wd but not in awd.

[the roadie]

If it was stuck in A4WD then your vehicle would be vibrating like crazy when turning on dry pavement (part-time systems don't like to be activated on dry roads). That is probably the safest way to find out if it is stuck in A4WD. Drive it too long in the dry with an active front axle and you'll just be stuck.Sure about that? 4HI and 4LO are bad modes for dry pavement, but A4WD needs to detect significant wheel slippage before the transfer case clutches engage. Slow turns in parking lots won't trip the sensors, just like slow turns won't fire off the automatic G80 locker.

There was a detailed discussion (with my colorful drawing - remember?) about why 4HI and 4LO would cause dry parking lot scrubbing, and it was not at all about the presence or absence of a differential locker. It was about the difference in turning radii between the front and rear differentials, with torque transfer between the front and rear due to the transfer case. But in A4WD mode, at low speed, and dry pavement with no wheel slippage, the clutches won't be engaged, there's no torque transfer, and no bind-up.

On Happycamper's post: You're right about full-time AWD (Autotrak) not sending power to the front wheels all the time, but any truck that has a 4HI and 4LO options, will have a front axle disconnect and show a A4WD option on their transfer case control, not AWD. The AWD system always allows the front wheels to spin the shaft from the front differential to the transfer case, or else the transfer case could not detect wheel slippage. The shaft is actually being spun from the front, not the back. But just because the shaft is turning doesn't mean torque is being transferred. That's up to the transfer case clutch pack. Reading the theory of operation from the service manual is what enlightened me to the state of the hardware.