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Duramax Fifth Generation: 2011-2016 (LML) Discuss the fifth generation (2011-2016) of the 6.6L Duramax diesel engine & associated components. Engine related discussion ONLY.

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Old 10-09-2019, 03:55 PM   #1 (permalink)
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0ct 9 '19
Background : my 2013 3500 tried to kill me - no joke - suddenly with no warning, went into REDUCED ENGINE POWER mode. Coming up the grade out of Kingman, AZ towing our 11,000 lb. boat & trailer. At night in the rain. Speed went from normal Interstate cruising speed ( 65 - 75 mph) to 10 mph - not even giving me time to pull over - luckily, the big rig 0TR behind me was able to slow down in time and signal others.

Bottom line - I am scared now of it again going into "limp mode". Some of us use our trucks as trucks, meaning when towing, you go into limp mode, your truck is effectively disabled.

Some more background - if you run low on DEF, your truck's computer will warn you, several times, hundreds of miles in advance. When your DPF needs service, you get NO warning. Not funny.

Yes, of course I am trying to arrange for a full delete. In the meantime, DPF Alternatives in Phoenix (a nation-wide franchise) did a good job of cutting my DPF out, cutting it apart, cleaning it, re-installing with "quick disconnect" fitti9ngs & I got a guy to clear the entire history.

Truck now normal - again, while I await a "full delete". I just got a "engine check light". My 0BD II "reader" says P0420 "permanent" (1) Cat system low efficiency (2) three way cat TWS low efficiency. I can "clear" the "engine check" light with my own OBD reader, but it does show in the history as "permanent".

Question to you GM/Chev computer buffs. I am scared to use the truck now for what I use it for - towing - for fear it will go limp on me. Is this a "soft" or "hard" code....specifically, is there ANY way the computer can use this code to trigger another "REDUCED ENGINE POWER, again effectively disabling my truck without warning?

2013 Chev. 3500 Duramax/Allison crew cab pick up 80K miles at purchase. ( June 2018 ) White in color. Bone-stock except for air shocks in rear (to compensate for removing one rear spring from the spring-pack to give a decent ride on those occasions when not towing heavy loads ! ). Added small winch in pick-up bed to help load our jet ski up its ramp. Normal use is towing approx. 11,000 lb. trailers ( our Bayliner on its 3 axle, or my '38 Packard V-12 in its "box" trailer. Air box modified to accept a cabin air filter the system was obviously originally designed for!

Last edited by OkDually; 10-09-2019 at 05:07 PM. Reason: sig
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