Diesel Place banner

U0101 and U0106

10764 Views 5 Replies 3 Participants Last post by  Smokin06LLY
U0101 - lost communication with TCM
U0106 - lost communication with GPCM

Truck sat for a month or so without being started. Battery - 06 LLY - was dead - after charge, the truck started right up and ran great but had a CEL. Above are the codes that were pulled. They have been cleared, but I am new to diesels and I want to make sure that the codes were related to the dead battery and I don't have anything further to be concerned about.


1 - 4 of 6 Posts
I forgot to mention that it is completely stock - no aftermarket anything.

I hope to take delivery of the truck Thursday!! :D

Can't wait to tow my 8500 lb fifth wheel rv. S/B night and day from 6.0 Gasser (Great truck, but not enough).

Yeah - the glow plug recall/reflash was done at 46 miles - now has 86.
RayMich;1547544; said:
The ECM will set these codes when the battery is dead. The ECM will have trouble talking to the TCM or GPCM if the battery voltage is below 9 volts. I would clear the codes and keep an eye on the voltmeter just in case the alternator might be acting up, but I wouldn't worry about it too much.

Make sure your batteries are fully charged. My main concer would be if the dead batteries froze in the cold temperatures; if so, you'll very likely have to replace the batteries.
Thank you. Dealer replaced batteries at my request, since all this happened before I take delivery. So I should be good to go.
1 - 4 of 6 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.