Well pretty sure I need a new actuator motor, at the very least. But I wanna run this by you all. Unlike most that seem to have a rear locking issue, I am getting two different system faults.

- Tranmission fault, reduced traction. When this happens I can drive around just fine and even select programs, etc. There is no apparent issue.

- Transmission fault, stop safely. When this happens I get ABS, Traction, brake (not parking) lights. And if I drive it then I end up with EAS being upset and while it does not say or indicate on screen that it lowered, it has to access.

Either fault only happens at startup and right now I get either 100% of the time. If I get the "stop" message I can restart and get just reduced traction. I ran codes on all the systems. Transfer case had a TON of codes but they never came back after clearing so they may have been stored from something prior. EAS, Engine, trans, terrain control - all clear of faults. Only two consistent faults are "clutch actuator stuck" and "clutch position is not learnt". I am not hearing any screeching from the rear, but every time I start up and shutdown I get a mechanically hum from the rear diff. Like the actuator motor is operating. Sounds normal. No clunk, no screeching.

Thoughts before I dig into this too deep?

 

The bit about the clutch position certainly points at the actuator....the 2nd transmission fault though, with the "stop safely" bit....I feel like I had that years ago and it was diagnosed as a Transfer Case Module...my memory is foggy though.

 

"clutch position is not learnt".

is definitely the diff motor.

 

Small update. Truck seems to be operating fine except the errors above. I even took it on some trails and the rear diff appeared to lock when commanded. So operationally its okay. The transfer case had yet to show any faults, but the rear diff is occasionally shows pretty much every code it can generate.

Powertrain control module RAM error
Powertrain control module ROM error
Trans Fluid temp sensor B - circuit low input
Trans Fluid temp sensor B - circuit high input
Cluth temp too high
Sys voltage too low
Sys voltage too high
And the list goes on.....

But as before, no other system is generating any faults. Trans is good, transfer box, etc. So as of now I am going to have to examine wiring or possible replace the rear diff module. While I am sure I need a rear diff software update and may have to replace the actuator, this problem seems new and unrelated now. Will update when I can dig into it deeper.

 

That list of faults almost makes me think corroded ground

 

...it could lead to the clutch packs failing and the diff "clanking" periodically.