Multiple error messages, trans starts in 2nd gear, gear indicator not working

[JAKnight]

This morning I remote started my truck and as I got closer it shut off. That's never happened. When I got in and started the truck it displayed multiple errors dealing with stability track, parking assist, ABS. I also noticed the gear indicator is not working. When I put it in gear (Allison 6 speed) it went into gear hard which it never does. I pulled away and it was in either 2nd or 3rd gear from a standstill, which has also never happened. When I stopped and put the truck in park it does not unlock the doors like it is supposed to do. Any ideas on what might be wrong? I've never had any problems at all with the truck until this. Any help is appreciated.

[808]

Believe your model has the dual battery setup.  Mine is a single battery setup but it has done weird things as soon as the battery loses some power (voltage OK but loss of CCA).  My last battery I replaced, it was causing stabilitrak messages while turning (electronic steering heavy load), dash would flicker on and off with the infotainment system.  The previous time my battery went out, it also had all kinds of warning lights flash on the dash, weird locking of the doors and windows, etc.  I believe it threw a code for low voltage to the BCM or something like that too - low voltage to the BCM and all kinds of things go haywire.  Don't know why it would affect your trans, but if the trans computer talks to the BCM, I'd guess that might be why.

 

I'd first check the batteries for not only voltage, but cold cranking amps as well.  Two off my bad batteries appeared to be normal by multimeter test but the cranking test showed they were down on juice.  I have had a battery die in my 2015 in less than a year - I'm on my 4th or 5th battery now lol.