Exhaust Fluid Poor Quality Duramax 2024. Driving home the other night on an 11 hour drive, i got the warning saying diesel exhaust fluid quality poor, and then a countdown from 100 miles until speed limited to 65 mph. Had a check engine light pop up about cylinder 3 glow plug open.

In this video i go through all the steps to troubleshoot poor quality def warning. I’m working on this 2015 chevy silverado duramax (i’m new too def systems) and has on the dash “exhaust fluid quality poor” and “speed limited to 4 mph”.