2020 3500 Diesel DPF Issue and Replacement

JW2020 · July 9, 2021

I have a GMC 3500 DRW that just had the DPF replaced at 8,200 miles which is unacceptable really. I use the truck to pull a 16K Fifth Wheel and was 550 miles into my trip when the reduced engine power notification came on and the MIL went off. The codes thrown were P2463 and P0422. What is interesting to me is that no warning messages or notifications to keep driving the vehicle for regens were given until this popped up. Also, during that 550 miles, nearly a full tank of DEF was consumed which makes no sense for multiple reasons. In fact, I think the truck uses way too much DEF anyway. So, it was using the DEF and not putting out any warnings whatsoever. Apparently code P2463 is set as a result of excessive soot loading. According to what I have found, excessive loading occurs at around 140% after its made multiple attempt to regen and you've ignored messages. According to the dealership, this sucker was at 237%. I don't understand how that's possible with zero warning and continued consumption of DEF other than some other issue, but it was operating normally according to the documents they gave me. However, the also performed a recall that I was never informed about. N202300791 Which is a reprograming of the Reductant Control Module, but when I asked if that could have caused it, they had no idea. So, i wanted to see if anyone else had a similar problem like this. I am concerned that while they replaced the DPF under warranty, if it wasn't the Module, then this could happen again. This truck is really only used for this particular trailer, so after getting it to the closet dealer, I flew home and got my 2020 GMC 3500 SRW and used it to tow the trailer back. Same exact trailer, engine and everything, except for the DRW part. The SRW only used about 1/4 Tank of DEF for the complete 600 miles to get the trailer and the 600 miles back with the trailer. So, that makes me wonder if there isn't something wrong with the Dually...although maybe it was the Module. Thanks in advance for any thoughts on this!

Alan Juden · July 9, 2021

7 hours ago, JW2020 said:

I have a GMC 3500 DRW that just had the DPF replaced at 8,200 miles which is unacceptable really. I use the truck to pull a 16K Fifth Wheel and was 550 miles into my trip when the reduced engine power notification came on and the MIL went off. The codes thrown were P2463 and P0422. What is interesting to me is that no warning messages or notifications to keep driving the vehicle for regens were given until this popped up. Also, during that 550 miles, nearly a full tank of DEF was consumed which makes no sense for multiple reasons. In fact, I think the truck uses way too much DEF anyway. So, it was using the DEF and not putting out any warnings whatsoever. Apparently code P2463 is set as a result of excessive soot loading. According to what I have found, excessive loading occurs at around 140% after its made multiple attempt to regen and you've ignored messages. According to the dealership, this sucker was at 237%. I don't understand how that's possible with zero warning and continued consumption of DEF other than some other issue, but it was operating normally according to the documents they gave me. However, the also performed a recall that I was never informed about. N202300791 Which is a reprograming of the Reductant Control Module, but when I asked if that could have caused it, they had no idea. So, i wanted to see if anyone else had a similar problem like this. I am concerned that while they replaced the DPF under warranty, if it wasn't the Module, then this could happen again. This truck is really only used for this particular trailer, so after getting it to the closet dealer, I flew home and got my 2020 GMC 3500 SRW and used it to tow the trailer back. Same exact trailer, engine and everything, except for the DRW part. The SRW only used about 1/4 Tank of DEF for the complete 600 miles to get the trailer and the 600 miles back with the trailer. So, that makes me wonder if there isn't something wrong with the Dually...although maybe it was the Module. Thanks in advance for any thoughts on this!

@JW2020, I have recently had a similar situation. I have a 2020 Silverado 3500 SRW with 33,000 miles. I'm from Missouri and we were doing a 10 day trip in Colorado to various places in mid-June. The family and I were pulling our 5th wheel toy hauler and had come over a mountain pass and stopped to take pictures. I left the truck idle because we were only stopping for a few minutes (maybe I should have used the high-idle switch when I stopped).

When I got back to my truck after the few minutes of being stopped, there was a message on the screen saying to "please continue driving...". It apparently tried to do a regen while sitting there idling. Of course we were going DOWN the mountain so we weren't getting super high on the RPM's. My truck also gave the message about reduced engine power. I have a bluetooth OBD reader and use the "Torque" app (on Android) to read engine codes. I only had a single code which was P2463 (Diesel Particulate Filter Restriction - Soot Accumulation). We had about an hour to complete our drive to get to the campsite and as we drove to our campsite, the truck and trailer started tugging almost as if I was having transmission issues which scared the hell out of me. I believe it was from the reduced engine power whenever I would hit the pedal.

I called a local dealership in Alamosa, CO and they were all booked up. We decided we'd hit the Sand Dunes National Park as planned in the morning and head out a day early so that we could move to our next destination and get the truck looked at by a dealership that said they could squeeze me in up in Gunnison, CO. Well, the next morning we are heading back to the camper after visiting the sand dunes and about 1.5 miles away from our campground when the truck lost all power. The truck would start and idle, but then shut off after about 5 seconds. I started getting a 2nd code at that time which was a P2453 (Diesel Particulate Filter Differential Pressure Sensor Circuit Range/Performance). Had to have the truck towed to the local shop that was all booked up (on June 15) and I just got the call the other day that my truck is done. My truck and trailer have been sitting in two different spots in Colorado for nearly a month while the truck is fixed.

GM Assistance really saved the day for us because they said "as long as the fix is covered by the warranty" they'll pay for the tow to the next location ($1,200 - for 3 hours away).

To top it all off, last year (2020) in June I had owned the truck for a month and it had around 13,000 miles (it was used) and the entire exhaust needed replaced because of a similar DPF issue but it didn't make the truck stop running or reduce the engine power.

I'm heading to Mexico for a vacation this weekend and picking my truck/trailer up next weekend in a "quick" 30+ hour road trip...wish me good luck.

foxrider805 · January 29, 2022

Read this post and have very similar issues with my truck. 2020 6.6 3500 approx 27,000 miles. Noticed my truck was constantly reving up when thrown into park. I live near the coast in California cold Mornings are around 30f days are 60-70f.

After a few weeks of the truck reving up it finally stopped doing it as it was random. The other day coming up a steep grade it through an engine code P002. Took the truck to the dealer, the outcome: I need a new dpf. Of course part is on back order and expect it in 3 weeks. Read some threads about a module that controls the def fluid??? Not sure cause or reason my truck sees mostly freeway use.

JW2020 · January 29, 2022

On the high idle part, was that generally during the cold morning hours or any time of the day you put it in park? The truck will high idle when it is cold outside in park. Just curious because I’m not sure the two are interrelated. But at 27K you shouldn’t need a new DPF, that’s for certain. Have them check the various bulletins out there and see if your truck qualifies for the module replacement. It couldn’t hurt and you certainly don’t want to pay for a new DPF out of warranty. That’ll add up to several thousand. I haven’t checked, but I’d imagine these would be considered part of the powertrain and have the longer warranty. The concerning part is the DPF is considered a consumable and isn’t necessarily warranty replaceable because improper maintenance and ignoring prompts could cause failure. I believe the fact they replaced mine under warranty means something else is going on and they know it’s a problem. Hopefully they get the part soon.

Njmurvin · January 31, 2022

If I'm reading the 2020 warranty correctly, DPF should be covered for 5yrs/50K according to the Federal Emissions Warranty. In California, that's extended to 7yrs/70K.

Galaxy · January 31, 2022

There is a new bulletin released for 2020 trucks with L5P. #21-NA-214. In case you have DTCs P2002, P2463, P2459, P144E, P0421, P0422, P0106 and/or P20EE, ECM and TCM may have to be updated with a new program.