auto 4x4 not engaging

[iggy1718]

Is there a sensor that monitors the wheel slip and can it break and not let the system engage? Where is it also if there is one?

 

[dmac0923]

first off are your 4x4 and 4wd low lights cycling on and off when you first start the truck?

if they arent lighting up then its your control module located behind the passenger side kick panel

 

[iggy1718]

no all the lights are working fine and everything works when I switch to low or high but the auto doesnt work. I have replaced the transfer case with another exact one and it was fine before. Is there a speed sensor somewhere that detets the difference in rotation of the output shafts that could have gone bad?

 

[zonianbrat]

I wish I actually had this problem. When you find out what it is please post it up. Many people do the BWM to have your "problem". I am considering doing it as I would rather be the one to know when to put it in 4x4 rather than the truck!

 

[gijoecam]

first off are your 4x4 and 4wd low lights cycling on and off when you first start the truck?

if they arent lighting up then its your control module located behind the passenger side kick panel

Huh?? Not sure what you're talking about, but I suspect you have your generations wrong... Second-gen's controls are all in the IP.

no all the lights are working fine and everything works when I switch to low or high but the auto doesnt work. I have replaced the transfer case with another exact one and it was fine before. Is there a speed sensor somewhere that detets the difference in rotation of the output shafts that could have gone bad?

If 4high and 4low work properly, it's not a GEM issue. If it's strictly 4auto not locking, it's not likely a sensor either... THe system would detect a fault and flash the lights if a sensor was out of whack. My money would be on the TOD relay (Torque On Demand Relay). It's located on the passenger side of the dash, to the right of the stereo, almost behind the edge of the air bag.

That's where I'd put my money...

-Joe

 

[dmac0923]

Huh?? Not sure what you're talking about, but I suspect you have your generations wrong... Second-gen's controls are all in the IP.



If 4high and 4low work properly, it's not a GEM issue. If it's strictly 4auto not locking, it's not likely a sensor either... THe system would detect a fault and flash the lights if a sensor was out of whack. My money would be on the TOD relay (Torque On Demand Relay). It's located on the passenger side of the dash, to the right of the stereo, almost behind the edge of the air bag.

That's where I'd put my money...

-Joe

yea sorry about that with the gens, ive had that control module behind the pass kick panel go bad on my brothers 01 sport and my 02 ranger.

 

[iggy1718]

Thats where i will start also thx

 

[wingman98]

has anyone found a fix to this problem? Sorry for the Bump

 

[Dave98XLT]

I have a similar problem, and I started another post.

The part about the dash lights coming on during startup is nice to know.

My shift motor is working, too, get a good clunk into 4WD-Low.

However upon wheel slip in 4wd-auto I get a gouging noise like it is trying to engage, but no front wheel power.

Also with the switch in 4WD-high there is no front wheel power either.

Is there a way to jumper the "torque on demand" relay to test out the clutch? Or should I get a replacement relay? Is there a way to check codes or otherwise check the sensors (OBD2 or flashing lights, etc)

If I figure this thing out maybe I will write up a sticky thread procedure like the no-start thread (best thread on this site if you ask me).

I can't seem to find anything concise on how to troubleshoot this except the brown wire mod which I am not interested in doing except if it is a last resort.

 

[Dave98XLT]

So I checked the voltages at the "torque on demand" relay and found it is getting 12V on the blue wire and the yellow wire. But is is only getting about 2V on the brown wire. So I think I will try to locate another "torque on demand" relay and swap it out.

Also the 2nd Gen wiring diagrams are tremendously helpful.