4wd serv and wont shift out of 4 low

[Granite Crystal 1500]

So the three year old battery died on my 2022 big horn. Parked the truck in the drive and then attempted to start it the next morning. I pushed the start button and the dash light up like a Christmas tree. 4wd serv, 4wd low & 4wd high constantly flash. Starter did not work. I replaced the battery and it started. 30 seconds later the dash lit up again. Tried all the simple tricks like disconnecting the battery all night and still the same result. Took it for a drive and it will not shift out of 4 low. Checked all the connections I thought would be involved. Still no change. has anyone else had a similar issue?

 

[HSKR R/T]

So the three year old battery died on my 2022 big horn. Parked the truck in the drive and then attempted to start it the next morning. I pushed the start button and the dash light up like a Christmas tree. 4wd serv, 4wd low & 4wd high constantly flash. Starter did not work. I replaced the battery and it started. 30 seconds later the dash lit up again. Tried all the simple tricks like disconnecting the battery all night and still the same result. Took it for a drive and it will not shift out of 4 low. Checked all the connections I thought would be involved. Still no change. has anyone else had a similar issue?

Need to get a scan tool on it and see what codes it's throwing. Something seems like it might be fried. Could also let it sit overnight with battery hooked up . Maybe just needs time.

But I'd definitely be trying to scan for codes

 

[Granite Crystal 1500]

Thanks for the scan tool advice. That was my next attempt. I will see what the codes are and go from there.

 

[Snekpete]

Lighting up like a Christmas tree is potentially the CAN-C Star connector failure. There are a bunch of threads on this. Search on "star connector" and/or "Bus Issue".

 

[Granite Crystal 1500]

Lighting up like a Christmas tree is potentially the CAN-C Star connector failure. There are a bunch of threads on this. Search on "star connector" and/or "Bus Issue".

Thanks for the advice. I will look those up.

 

[Granite Crystal 1500]

Well here is the update to my issues. I replaced the front differential axle lock actuator (68399418aa) with no change on the tree lights and sill stuck in 4 low. I then ordered the "dealer only" transfer case gear motor (68679351aa) and with the holidays waited for it to arrive for a few days. Received the replacement gear motor and installed it. Finely got it into 2wd! Took it for a short drive and now it will not shift into 4wd auto or any 4wd mode. Got a code reader to say its U0403-00 Implausible Data Recieved from T-Case.
Tried all the "simple" TCCM resets and nothing reset. The good part is the Christmas tree lights are gone but all the 4wd selections just flash and does not switch out of 2wd.

I have scheduled an appointment at the local Ram dealer early next week. I'll post when I get some feedback from the dealer if the control module is fried.

 

[kapinallinen2]

Interesting to see what the cause is.
I would bet on the CAN-C but who knows.