When I say our truck went into “limp mode” what I mean is the dash displayed an “engine power reduced” message. The truck is a 14 Silverado 3500 diesel dually. Before that message popped up the dash told me that the truck needed to run a regeneration (regen) cycle and clean out the diesel particulate filter (DPF), or something like that.
I found out several interesting facts about the LML Duramax engine during this experience.
- The truck will enter limp mode after about three minutes of driving.
- While in limp mode you can only get up to 32 MPH, going downhill.
- It can only run the regen cycle over 35 MPH.
- If you turn the truck off and restart it you’ll get another three minutes to get over 35 MPH.
- Once you’re able to get over 35 MPH you have to drive about 30 miles for the regen cycle to complete.
- The truck will run, and sound, much better afterwards.
Yes it can be a little scary when your work horse truck suddenly doesn’t work. Luckily with a google search, a code scanner, and some trial and error I was able to figure it out. We were just lucky that it wasn’t a travel day.