U0101 and U0106

Smokin07;1547116; said:

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.

TIA

Bill

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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.