LMM: help please!!! randomly goes into limp mode....

dahminater

heavy-duty diesel mechanic
Mar 16, 2015
4
0
0
born n bread montana
Ok, so my brother bought and 08 gmc 1ton dulley with 70,000 miles, for his new work truck, his girlfriend has been driving it lately and it goes into limp mode randomly, she turns it off for about 20 minutes or so and it's back up n running again, anyway, my bro is about ready to set it up for work and he can not afford for it to go into limp mode on the job, what I'm wondering is, is there anything he can do to permanently fix this problem? He doesn't seem to care what it costs, just needs a reliable truck, oh and it had two codes when scanned p0401, and p0106, egr delete mabie? I'm not really sure about duramax's, I'm used to working on mining equipment and class8 trucks, anyway, any info would be greatly appreciated:eek:
 

sanchezsjmarine

New member
Mar 25, 2015
1
0
0
I had a similar problem. I fixed 2 things. First, my batteries looked old so I had them tested and sure enough, they were shot. Next was my lift pump, not CP3, needed to be replaced. After this, My truck runs like a dream. Maybe this will help you, maybe it wont, but either way, I always welcome any advice any fellow duramax owner can give. Hope you get it figured out.
 

NC-smokinlmm

<<<Future tuna killer
May 29, 2011
5,204
363
83
At Da Beach
Sounds like soneone blocked the egr with a plate. Check in between the uppipe and the egr cooler and look for a tab sticking out where the gasket is. If there is a tab someone blocked it and removed the programming before they sold the truck. If there is no tab there coukd be excessive soot buildup in the cooler itself. I would delete it if that were the case, if there is a plate blocking it just get tuning to block the code...
 

trashygasman

Slowly but Surely
Dec 18, 2008
637
1
18
49
Washington, OK
I had a similar problem. I fixed 2 things. First, my batteries looked old so I had them tested and sure enough, they were shot. Next was my lift pump, not CP3, needed to be replaced. After this, My truck runs like a dream. Maybe this will help you, maybe it wont, but either way, I always welcome any advice any fellow duramax owner can give. Hope you get it figured out.

My dads LMM had a bad battery and it wouldn't let it regen due to low voltage causing it to limp randomly. I would have the batteries checked also.