push button 4x4 to 4 on the floor ? ?

[volunteerff21]

Is the front actuator a TLA or is it the servo style.

90% of the time if it's not the front actuator it's the control head in the dash. They are notorious for cold solder joints.

I had a pdf around here somewhere, let me see if i can find it...

Edit: see if my link to the pdf still works in this thread - http://www.gmt400.com/forum/showthread.php?t=17252

Edit 2: crap, looks like it was deleted. Pm me your email if you want it and I'll see if i can find a copy when i get home.

PM sent.

Actuator is servo style.

Somethings I should have mentioned in the first post. I tried replacing the front actuator and transfer case actuator (thing that screws in on top of the T-Case). Neither worked so I returned the parts. About a year and a half ago, right after I bought the truck, I had to replace the dash switch.

 

[great white]

PM sent.

Actuator is servo style.

Somethings I should have mentioned in the first post. I tried replacing the front actuator and transfer case actuator (thing that screws in on top of the T-Case). Neither worked so I returned the parts. About a year and a half ago, right after I bought the truck, I had to replace the dash switch.

Even a new dash switch is suspect.

But it sounds like you're done everything except the actuator and the rotary encoder.

Run the 4x4 DTC retrieval procedure in the PDF file and see what it says....

 

[volunteerff21]

Even a new dash switch is suspect.

But it sounds like you're done everything except the actuator and the rotary encoder.

Run the 4x4 DTC retrieval procedure in the PDF file and see what it says....

Came up with DTC #1

 

[great white]

Came up with DTC #1

Dtc 1 indicates power interruption. It is supposed to clear itself after 5 on/off cycles of the key (ie:run position). If it does not clear, you may have a power problem.

Check all the fuses listed on page 27 of the PDF.

If those aren't the problem, you could have a wiring short or it could be those solder joint on the dash module.

Good news is there is nothing so far indicating the rotary encoder or force motors. Those get expensive.

Another question is can you hear the front axle actuator engaging? Mine is the servo actuator and I can hear it when it engages. If the actuator doesn't engage, then the 4x4 shift process will not complete.

If all that is good, work your way through the troubleshooting charts in the PDF. You may want to even start there after you confirm the fuses are good.

I would also suggest you check the grounds at the engine block. The selectable 4x4 system has a ground wire that goes back to the engine block and if the connection is corroded or has "futz" in the connection it can raise the resistance high enough in the ground circuit that it manifests itself as a power fault. However, when this is the case, you usually start seeing other electrical problems as most of the systems run back to the same engine block point for ground reference...

 

[volunteerff21]

Dtc 1 indicates power interruption. It is supposed to clear itself after 5 on/off cycles of the key (ie:run position). If it does not clear, you may have a power problem.

Check all the fuses listed on page 27 of the PDF.

If those aren't the problem, you could have a wiring short or it could be those solder joint on the dash module.

Good news is there is nothing so far indicating the rotary encoder or force motors. Those get expensive.

Another question is can you hear the front axle actuator engaging? Mine is the servo actuator and I can hear it when it engages. If the actuator doesn't engage, then the 4x4 shift process will not complete.

If all that is good, work your way through the troubleshooting charts in the PDF. You may want to even start there after you confirm the fuses are good.

I would also suggest you check the grounds at the engine block. The selectable 4x4 system has a ground wire that goes back to the engine block and if the connection is corroded or has "futz" in the connection it can raise the resistance high enough in the ground circuit that it manifests itself as a power fault. However, when this is the case, you usually start seeing other electrical problems as most of the systems run back to the same engine block point for ground reference...

I didn't have much time to mess with it last night. A buddy called me up right after my last post needing my help with something. I'll work on it some more tonight and post up the results in a new thread. I feel we've sidetracked this one long enough lol.

I can tell you that last time I checked (several months ago), the front actuator wasn't engaging. Had it unscrewed from the axle, had a buddy push the button, and nada, no movement. Tried replacing it with a new one, and same result.

The truck does have a brand new ground strap from the passenger side head to the firewall, and then firewall to frame.

 

[great white]

I didn't have much time to mess with it last night. A buddy called me up right after my last post needing my help with something. I'll work on it some more tonight and post up the results in a new thread. I feel we've sidetracked this one long enough lol.

I can tell you that last time I checked (several months ago), the front actuator wasn't engaging. Had it unscrewed from the axle, had a buddy push the button, and nada, no movement. Tried replacing it with a new one, and same result.

The truck does have a brand new ground strap from the passenger side head to the firewall, and then firewall to frame.

There's a wring harness ground that goes right to the blcok somewhere. On my diesel, it's on the back passenger corner of the intake manifold. Not specifically sure where it is on a gasser anymore....

 

[TXVortec454]

Does anyone have this PDF great white uploaded years ago???