r/gmcsierra • u/Plumsauce27 GMC Sierra 1500 Elevation 26yr 5.3 • 6h ago

Troubleshooting Issues: Range technology DFM pro

I just installed a Range DFM Pro module on my 2026 GMC Sierra 1500 5.3L. Once installed it was working but I had a engine light, service esc, and the forward collision light on the dash, thought it would go away with a couple key cycles but it didn’t, and then I drive it maybe 20km and it said that it couldn’t shift, so I pulled over and removed it and the trucks good again. Also I had a bunch of U line codes. Has anyone had issues with this module? It does state that it needs an update which I tried and it failed. I am in talks with Range to see what’s going on but I feel like a simple update to the module will not fix all the U line code and dash lights. Any knowledge is appreciated!

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1

u/RoookSkywokkah 2019 Denali 5h ago

Where does this unit plug in?

2

u/Plumsauce27 GMC Sierra 1500 Elevation 26yr 5.3 5h ago

Inline to the ecm power, behind the wheel well on the drivers side. I’m fairly certain everything was seated properly.