Helppp!! I have a 2009 Tahoe , it will run perfectly fine for weeks and all the sudden the line under the gear ( gear indicator ) will go out and the truck goes into limp mode . When it first happens the scanner doesn’t communicate, let it sit for two weeks jumped it and got a u0013 which I think because it was dead and also got a i0100 code . But now the indicator is back and it’s running fine . I pulled the fuse box up and don’t see any corrosion or anything . However the stabilitrac light is on but not pulling no codes . Anyone know where I can start ?
I have an '09 and those codes don't appear in the shop manual for it. The U0100 does show up in the shop manual for my 2013. It says that the first code is probably the offending module that can no longer communicate on the network. When I pull up that list, U0013 is not on it.
When we pull up codes, most of them are followed by a 2 digit symptom code, like U0423 00 or U0423 71, these tell us exactly the malfunction with that code.
Ok, the U0100 shows up in the 2009s Control Module U Code List, it means communication has been lost with the ECM.
One thing I would do before any more diagnostics is to make sure the battery is fully charged or replaced if it is 3+ years old. A bad cell in a good battery that passes tests can even lead to weird readings like this. Check the positive and negative cables for corrosion too. You might also unplug the connectors at the ECM under the hood and inspect them for corrosion and carefully plug them back in as well.
Are you using a code reader to pull codes or something more advanced?
