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Changes to DEF Limp Mode

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jenninr

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[MOD: replaced link with approved agency link]

www.epa.gov

At Iowa State Fair, EPA Administrator Zeldin Announces Diesel Exhaust Fluid (DEF) Fix | US EPA

EPA Administrator Lee Zeldin announced new action to protect American farmers, truckers, and other diesel equipment operators from sudden speed and power losses caused by diesel exhaust fluid (DEF) systems.
www.epa.gov www.epa.gov


It sounds like DEF limp mode changes are coming and they won't be nearly as harsh. "It’s a similar story with heavy-duty pickups, which will only be limited to 45 mph after 4,200 miles or 80 hours with low DEF levels."
 
Last edited by a moderator:
Amazing. Half the reasons the truck goes into limp mode are unnecessary entirely. Any failure to do with the DEF/SCR system should have a similar range before limp. I should be able to get home with my camper on a dead NOx sensor, DEF pump, DEF heater, DEF level sensor, DEF injector, EGR valve, EGR cooler bypass valve, throttle valve, etc.

Give me that software update for my 2014 now.
 
I just went through a DEF derate about a month ago. I live in far northeast, remote and very rural California. While traveling home from a trip the "Service DEF System, See Dealer" warning came up and gave me 91 miles before derate. My closest dealership, which is my dealer, was 110 miles away, while home was 96 miles away. I chose home, and when it it hit that 91 miles derate threshold another warning came up that told me the truck would go into actual 5mph limp mode at either the next engine shutdown, refueling, or extended idle time (what that time is I do not know).

The truck operated normally and I got it home without a derate. I had it towed to a local mechanic who got me back on the road. I haven't taken it to a dealership yet (my dealership's very good mechanics both jumped ship and went to work for the local municipality), but I'm hoping it was simply a glitchy sensor. Something like this proposal would give us some breathing room to get our trucks safely to the right place without the hassle and expense of towing.

Gawd, the EPA is an awful agency staffed with truly awful people. I hope Admin Zeldin can make it a more sensible PUBLIC SERVICE agency.
 
jenninr said:
It sounds like DEF limp mode changes are coming and they won't be nearly as harsh. "It’s a similar story with heavy-duty pickups, which will only be limited to 45 mph after 4,200 miles or 80 hours with low DEF levels."
Click to expand...
Please share this info. Thanks.
 
Wonderful. So how do we get our trucks reprogrammed for this change? Are the manufacturers/dealers just gonna do it for free?
 
IMHO, I wouldn't hold your breath.

Unless NHTSA makes it a safety recall and compels automakers to flash a mandatory recall fix, even if they make something available, you'll have to pay for it.
 
Brutal_HO said:
IMHO, I wouldn't hold your breath.

Unless NHTSA makes it a safety recall and compels automakers to flash a mandatory recall fix, even if they make something available, you'll have to pay for it.
Click to expand...
Yup, thats exactly what I think..... we'll be paying for it.
 
Tims Ram said:
ErikTheRed: you are a funny guy!!! You said dealers do it for free.......:)
Click to expand...
I just paid $350 bucks for a gawdamm key fob for my Jeep. And the parts guy gave me a 'deal'. I doubt Stellantis or the dealerships will cut off a potential revenue source by actually doing the right thing by providing good customer service.
 
Is it as simple as software change to eliminate DEF? Seems there has to be some hardware changes?

What we might see if they start with new models and leave existing trucks with DEF still no easy way to delete.
 
sstoner911 said:
Is it as simple as software change to eliminate DEF? Seems there has to be some hardware changes?

What we might see if they start with new models and leave existing trucks with DEF still no easy way to delete.
Click to expand...

It's not an elimination, it's an easing of the derates and limp modes.
 
Seems to be a lot of confusion with SCR/DEF and "harming" engines. Most people didn't realize it was mandated for limp mode if it had the system if there was any problems with it. The engine would run fine without it.
 
CaptainMike said:
I just paid $350 bucks for a gawdamm key fob for my Jeep. And the parts guy gave me a 'deal'. I doubt Stellantis or the dealerships will cut off a potential revenue source by actually doing the right thing by providing good customer service.
Click to expand...
My local RAM dealer wanted to charge me standard blinker bulbs that I could (and did) get from NAPA for $2.50 for $37.00!! I asked him if he thought I was an idiot and he just laughed. "That's what we charge," he embarrassingly told me.
 
jenninr said:
[MOD: replaced link with approved agency link]

www.epa.gov

At Iowa State Fair, EPA Administrator Zeldin Announces Diesel Exhaust Fluid (DEF) Fix | US EPA

EPA Administrator Lee Zeldin announced new action to protect American farmers, truckers, and other diesel equipment operators from sudden speed and power losses caused by diesel exhaust fluid (DEF) systems.
www.epa.gov www.epa.gov


It sounds like DEF limp mode changes are coming and they won't be nearly as harsh. "It’s a similar story with heavy-duty pickups, which will only be limited to 45 mph after 4,200 miles or 80 hours with low DEF levels."
Click to expand...
I hope so. My truck is at my local diesel shop stuck in 5mph derate mode because they can't clear it. They replaced the DEF pump and a few other things but can't clear the derate. They're going to try to get the OEM software tomorrow to reset the ecm but if they can't, they're saying I'll have to take it to the dealer.

I'm out of warranty at 72k miles, just a pain in my ass to deal with this. It's been in the shop since last Friday morning at 8 am and I can't imagine the ass pain the dealer will be.

I need to move to Canada for about 3 days and shed weight, I hate this system so much.
 
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