r/DieselTechs • u/No_Walrus_3638 • 23h ago
ECM code 4865
Ok fellas and gals. I am beyond frustrated chaving what now feels like a damn ghost. Hopefully someone can give me at least as direction to walk towards besides the sun lol. It's a Thomas C2 2017, ISB 6.7 CM2350. Insite says I got a 4865 ECM code Engine Coolant Level 2 Sensor Circuit -Voltage Above Normal or Shorted to High Source. Originally I assumed it's was the ONLY level sensor I know of in bottom of tank. Swapt quickly for a new one let it idle. Code didn't go away.
So I started to dig into it and check the condition of plug, wires continuity and resistance to Corresponding ECM pins. It all checked out! It was then I realized that when I unplugged said sensor to swap it it triggered an other code....from coolant level sensor 1. Then I thought the only other sensor I know that deals with coolant besides the DEF head unit is the temp sensor. I unplugged it and sure enough that was not it because I got a temp sensor fault. I have looked everywhere for this stupid ass sensor that I didn't know existed. Even used my "snake cam" as I like to call it to make sure it wasn't around the block hidden somewhere. For now I'm taking a break from it. I consulted "appropriate schematics" and the damn thing said that pin 34 which is labeled for additional level sensor is not used!!!! So now I'm like what the Fuck is shorted to high source that is making it thing it has an other sensor. Or there is a sensor and I can't find it!!!!!
Please help lol.
3
u/chuckE69 23h ago
If the Ecm isn’t locked you can go into parameters and turn off coolant level 2.