Hard code P242F

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Bruce F

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Joined
Nov 21, 2024
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Location
Woodstock, IL
2015 F5500 6.7 264k miles.
Truck has gone into a "derate" no/low power.

Message center is constantly saying "exhaust system regen in process filter 100% full..."

It will not to the regen on it's own.
I clear the code and it is back instantly, without starting the engine.

Am I to understand the ECM is monitoring the exhaust pressures before and after the filter to determine is it is plugged?

I'd think when the engine is off the differential pressure would equalize and the code would clear??

Any insights where/what to check with this?
 

06 Dodge

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Location
Forest Grove, Oregon
Ram Year
2022
Engine
6.7L CTD
2015 F5500 6.7 264k miles.
Truck has gone into a "derate" no/low power.

Message center is constantly saying "exhaust system regen in process filter 100% full..."

It will not to the regen on it's own.
I clear the code and it is back instantly, without starting the engine.

Am I to understand the ECM is monitoring the exhaust pressures before and after the filter to determine is it is plugged?

I'd think when the engine is off the differential pressure would equalize and the code would clear??

Any insights where/what to check with this?
Ya may want to find a friend who has AlfOBD and can do a stationary regen along with all codes that may be hidden, then check your EGR, worn, broken or lose wires.....
 
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Bruce F

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Joined
Nov 21, 2024
Posts
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Location
Woodstock, IL
It would help if you list all the actual codes.

Sorry for the late reply.

There were a few. Some stored, some active.

P242F (as stated in the title) was the hard code that would not clear.
P1451, P2463, P0607, P0420, P2560 were some (I think all) of the codes encountered.

The coolant low code (2560) was rectified by closing the switch circuit until such time as the truck can come in and pull the inner fender to replace the magnetic switch.

The control module performance (P0607) I see now is a TCM code. This code was not in the truck upon initial scanning. I thought when it came up it was because the DPF DPS had been unplugged and the key turned on (I dismissed it at the time). Now I'm wondering if there may be a transmission issue in the future.
However, like I stated, it was not in the ECM when the truck came in.

Here is how the "repair" ended.
I had a friend come with their scanner(s). We told the ECM we had changed the DPF differential sensor so that the hard code would reset.
Once that was reset a stationary regen was possible using one of his scanners.
A short drive of 2 miles resulted in "normal" power (I've never driven this truck running properly, so don't know what it is supposed to feel like). Truck would accelerate pretty well, had turbo boost pressures that seemed normal (5-15psi).
While slowing to turn around and come back to the shop the 100% full message came on again, but no loss of power. We did another stationary regen (each took around 70-80 minutes).
I later drove for close to 10 miles, the 100% message again came on and that the truck was going to regen. I kept driving at an elevated rpm 4th(?) gear, and message then stated regen was done.

P0420 code popped up (this had been a stored code when I got the truck in the shop).
I cleared this code.

I then drove it for another trip to see what happens.
After 5-10 miles all was normal. I continued for another 5-10 miles, still normal. I kept going in a large circle debating if I should go back to the shop. After 25 ish miles I decided to deliver the truck back to the customer's yard. 55 miles total mostly around 45-60mph on country roads, no more messages or CEL.

Customer is happy to have the truck back.
I've instructed the owner to notify me when ANY messages, CEL, or drive ability issues come up, so I will find out sooner and can address, rather then when it goes into derate.

This exhaust system is not suited to the work use this truck does.
It is a small pumper truck for porta potties. So it spends a large portion of the day sitting at slightly above idle (1100rpm) pumping, then drives maybe a couple miles to the next stop. Maybe a couple times a day gets up to 50-60 mph. Truck probably never goes on the highway nor is under a heavy load. We live in IL and there's no hills to climb here.

Thanks to all who have responded and any other future suggestions are welcomed.

Bruce F
 
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