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Discussion Starter · #1 ·
Hi guys I'm new here I've been trying different threads and searching hard for answers. I've got a check engine light and it says 13 different codes. I hope this explains why my truck has the symptoms it does. I've researched the codes details and wrote down. But I can't distinguish witch is the one I need to address, bc I think one causes another and so on. Is that true?? Heres my codes, p0700,p0735,u1301,u100,u1255,c0306,c0327,c0359,c0379,c0550,b0790,b2725, and c0040. Anyone have this issue b4 please help
 

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Take 'em in their order;
700 triggers the dash light
735 5th gear slip/limp (it didn't like how the shift went)

U1301 Class 2 Short to Battery
That's^^ a big one clue

U0100 Lost Comm With ECM/PCM A
Not good, after the batt short

u1255 and others....domino loss of comm/network issues most likely....back to a short. :frown2:
Hopefully, fuse(s) blew and saved the modules.
 

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Discussion Starter · #3 ·
O my lord, thank u for the info. I'll update the pic and I'm with u i hope the fuses went before the modules. So I guess I'm looking for a short somewhere.
 

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Update, I found that a negative cable to one of the batteries was lose and a ground cable from the firewall to the hood was broke off and...the two wires going to my brakfluid reservoir were ripped out. Surely that was a cpl big items, u think. Man thanks so much for the ideas. I'm sure it didn't fix everything but I know it helped
 

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Update, I found that a negative cable to one of the batteries was lose and a ground cable from the firewall to the hood was broke off and...the two wires going to my brakfluid reservoir were ripped out. Surely that was a cpl big items, u think. Man thanks so much for the ideas. I'm sure it didn't fix everything but I know it helped
I would also look over the rest of the grounds, in particular the one from the engine to the firewall, since you said the other firewall ground was damaged. That ground failing will cause a LOT of check engine lights for communication failures to several modules including the TCCM and some others. May also cause all kinds of weird electrical issues in the cab.

On my 01 that ground was left disconnected after engine work, it melted 2 TCCM's before i found the issue, and all said and done, repairing that ground cleared 13 codes, and corrected issues from the radio not working right, to the cluster going nuts, to the power locks firing on there own. Our trucks, especially the OBS trucks (07 down) are very susceptible to issues from a compromised electrical and charging system.

The hood ground is not that important, its real purpose is to make your AM radio come in cleanly, so i dont think that will contribute to your issue.
 
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