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duramax codes

  1. 2020 duramax died

    2020+ LM2 Duramax Powertrain
    My son-in-law bought a brand new Chevy 3500 CC Long box two weeks ago. exactly one week after he got it (1000 miles on vehicle) it started making horrific knocking noises then shut off and would not start. Towed to dealer and they could figure it out (no codes) they drained all fuel and...
  2. Need help with Codes and spedo

    04.5-05 LLY Duramax Powertrain
    Ive had a few strange issues, possibly because mice urinated in the under fuse panel, I cleaned and used diaelectric grease the best I could Problem 1 The speedometer ready 80 mph at idle, Codes are as follows 674 0004 4800 0580 A480 which has been clear for a while 401 and 101, 74 also...