Feb 5, 2020 â€” Most of us with Duramax that have had a few fuel filter housing replacements ... it came up P21DD, something not common so we had to google the code. ... This failure will not cause the truck to go into limp mode, or not start.. Apr 5, 2019 â€” Had the DEF heater replaced today, that cleared the P21DD and ... Essentially, it's a limp mode with a progressive countdown to the next stageÂ .... Dec 7, 2020 â€” Additionally, will turning the truck on and off restart the limp mode travel restriction? and any idea what temp the DEF tank heater turns on at? fe9c53e484 wycksavir
Dec 10, 2015 â€” P21DD...I am 37 months and 91K miles, so it looks like it will be outta warranty. ... No limp mode, no limp mode, no limp mode, no limp mode, no limp mode. ... DuramaxÂ® 6.6L DuramaxÂ® Turbo-Diesel Engines are covered forÂ .... Results 1 - 7 of 7 â€” P21dd duramax limp mode. uxq 11.10.2020 11.10.2020. New PM! Discussion Poll Private Message. Hey Guys, My check engine light came onÂ ...