That's exactly what that is, the range position sensor. Maybe it's the brains and the motor is the brawn. In the older TCs they're integrated.
Stuck in 4WD
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That's exactly what that is, the range position sensor. Maybe it's the brains and the motor is the brawn. In the older TCs they're integrated.
That is what I was thinking. The TCCM knows exactly what position it has the TC in as the sensor is keyed. Likely you just pop the motor in and the TCCM displays whatever position the TC is in on the switch. You change the position selection and the TCCM tells the motor how many steps to go right or left and has the sensor to know when it got there.
Still wonder why the need for motor learn in that last bit of the shop manual that James displayed above. The guys making the video don't mention anything about starting in a particular position (like neutral) and no motor learn at the end...
After all this, I sure hope it turns out to be the motor and not just the sensor, or the TCCM or chafed wires from the harness coming loose and rubbing on the front axle drive shaft. I guess all that preliminary debug does make sense... 
Who knows, maybe some or all of the tests will get done when the motor is replaced. If I was going under there, I'd be curious and would do the tests before changing the motor out. It's just a couple of readings with a DVOM.
George B
¯\_(ツ)_/¯
When I have changed a stuck actuator I just looked at where the new actuator was positioned and moved the shift shaft to match and installed it.
You know, thinking about it, I wonder if the shop manual fragments James posted are for the right year? With the setup in the video, the resistance range test would be on the sensor and if not within that rheostats proper range, it would call out replacing the sensor, not the actuator (motor).
Also, I think the OP better check RPO's before buying anything.
Except that the component test is on the motor/actuator lock circuit, not the range selection. The lock circuit keeps the motor from moving when not changing modes.
Was this on your '13?
So basically, with this fault code, it is just checking that the coil in the lock solenoid is OK. If the lock solenoid is not bad, then it has to be the TCCM at that point.
I definitely would be doing the multimeter checks called out in James post before buying parts, especially with the revelation of the separate sensor and motor.
I went out and doubled checked and I do have the old style (RPO NP8) on my 2007 Yukon (but also have the rotary switch, like the NQH), so have the old style TC Motor with the integrated position sensor ring. The new style with the separate sensor and motor assembly (RPO NQH) I guess actually started in 2008, at least in Yukons.
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George B
¯\_(ツ)_/¯
No, I admit it was on my NBS but The control system works on the same principal. Also used the same process on our Envoy.
I went and read the troubleshooting that was shared. Thats not too hard to do.
It seems on the later models the motor and position sensor is separated. It looks like there isn’t any need to set the transfer case in a synchronized position between the motor and the TC, as the position sensor is not part of that pair. The TCCM knows what position the TC is in and only needs to tell the motor how far right or left it needs to go to select the commanded position.
On my 2007, it is the same as your NBS with the motor and TC keyed to each other. It is interesting to dig into the subtle changes in model years. In my '07, I have the NP8 TC/motor (old style, which implies the push button style TC drivers control), but I have the modern NQH style rotary switch. I guess they handle the differences in the TCCM calibrations.
I am still stumped what the motor learn does.
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George B
¯\_(ツ)_/¯
Thats good info. Thanks for sharing it. I may be just muddying the water here. Goi g to sit back and see what how this plays out.
Ha, you can't be muddying it any more than I already did, tracking on the old style TC motor install. It looks like the new style is a 10 minute job. Pop the old one out and install the new one. Done. I think... except for that pesky motor learn...
Ha, you can't be muddying it any more than I already did, tracking on the old style TC motor install. It looks like the new style is a 10 minute job. Pop the old one out and install the new one. Done. I think...
That's why you got the old style one.... so it would be a challenge.
And, yeah, we sure provided a lot of info that doesn't necessarily apply!
Well, selfishly, it applies to me, which is largely why I am spending the time. I want to keep that beast a while. The more I know now, the less aggravation when something breaks, and I know it will.That's why you got the old style one.... so it would be a challenge.
And, yeah, we sure provided a lot of info that doesn't necessarily apply!
This is a shot in the dark but my 04 has had a lot of these issues did you try the start in reverse to reset all the controlers? On a 2004 turn the key to on but dont start it. Put it into reverse then try to start it in reverse. It obviouly wont start in reverse but it resets all the controlers. I had to do this to reset the speedometer and air conditioning actuators. It should reset the 4x4 controller…
UpAndDown
Full Access Member
Just wanted to update this thread. Finally got around to working on the truck yesterday. It was the control module. I replaced it with the Dorman unit that has a programming procedure and it works again. Thanks again for all of the help. This is a great site.
Just got a dealer quote of $660 to replace the actuator motor. Just hoping that's not a 'guess'.
