U0100 Diagnostic Trouble Code Discussion for January 2026
Lost Communication With ECM
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| Help Request | Posted | |
| 2017 GMC Sierra 2500 HD SLT 6.6L No Start VIN: 1GT12TEY4H U0100: No communications with ecm. Checked battery's both good also checked fuses all good, but fuse 51 under hood fuses is ecm 30 amp fuse is good but has no power key on or off, check resistance at dlc between pin 6 and 14 reads 60 ohms. Relay 64 run/crank looking at relay from front of t... |
January 06, 2026 |
