Service 4 wheel drive after dead battery on 08 Silverado

XJ Eric

New member
Hey guys,
this morning went out to start my truck and the battery was pretty weak. 15 below zero temp.

My 08 Silverado LT Z71 with 189K miles had to be jumped and it's saying I have to service the 4 wheel drive. I hit the onstar button and they run the diagnostic. It comes up with lost communication with transfer case control module. I've been scouring the net trying to figure this out and nothing.

I've also noticed that it won't accelerate hard when I put the pedal down. It's got decent power but it won't rev.

Thoughts?:helpme:
 

whitexj98

New member
Remote start is disabled with MIL lights...

Lost Communication With Transfer Case Control Module is DTC U0102

There's a lot of diag for it but a few highlights:

-will cause the transmission to go into default gears
-A low battery condition was present, so some control modules stop communicating when battery voltage drops below a certain threshold.
-Battery power was restored to the vehicle and control modules on the communication circuit did not all re-initialize at the same time.

Is your battery good??
 

XJ Eric

New member
I erased the codes with a scanner. I tried pulling the 4wd fuse both when the truck was running and when it was off. No go on all tries
 

Johnnie Walker

Piece of Fish!
NAXJA Member
Push button 4wd I am guessing? TC 4wd actuator has probably failed. Maybe VSS?
As far as the battery, when was it last replaced? Have you actually had it tested to confirm good working? Just because it has been charged, and you can drive your vehicle does not always mean it is up to par. Go to your local Carquest/other parts store and have it tested.
 

XJ Eric

New member
Not push button exactly. Its the turn dial. But it is electronic. The lights arent lighting up on the dial any more. Its just strange that it died when the battery did. I know the jump start didn't do it. It was saying it needs service before I jumped it.
 

Johnnie Walker

Piece of Fish!
NAXJA Member
I meant electronic, forgot that they switched to knob. Electronic parts, sensors, etc. typically do not like low voltage to "run". Well, the service 4wd usually means that the actuator is failing. At least that has been my experience in working with newer GM products.
Your local parts store should carry, at least, the dorman replacement part.
 

XJ Eric

New member
Would it work If I borrowed a switch off of someone else's truck? Or does it need to be programmed at the dealership? I'm hearing crazy things like a new switch won't work (even if it is the problem) until I get it programmed at the dealership.
 

POSJ

New member
Do you have a heated garage? If not: take it to auto-hobby and pay the overnight fee and let the truck warm back up. Disconnect the battery all night and put it on a charger out of the vehicle. This will let the remaining charge on a few of the capacitors drain and hopefully once the truck is warmed back up to a better temp you can reconnect the battery and give the truck a fresh start with everything restarting at the same time. It is only a few bucks to leave it overnight and if it fixes it it's worth a shot. Minot has a way of killing vehicles, I was there 07-10 and my 07 Duramax had a rough winter one year.
 

XJ Eric

New member
Ive pulled the fuse and I disconnected the battery over night nothing worked. Put the battery on a charger overnight as well. Didn't pull it out of the truck though. Nothing helped. What does the warming the truck do?
 

POSJ

New member
My MAF would freeze intermittently and you might have something of the same nature but on a TC sensor.
 

POSJ

New member
I had to drive it at 25 mph in limp mode all the way from base to south hill one day...
 

XJ Eric

New member
Well it got to 40 today so maybe something thawed out. I was in the field so I didnt get to do anyyhing about it. Always in the field when the weather is good. Damn
 
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