[Hillbillyff]

So we towed our camper through the Appalachian mountains this past week. On the way there and the way back towards the end of the trip the check engine light came on and locked the tow/haul mode off. Once the truck cooled after being off and not towing anymore then the light would go off and could resume tow/haul mode as needed. I had already previously installed a small aux cooler and it had def helped with keeping the tranny temps down they didnt get past 210 the whole trip but I think they averaged high enough for enough hours for the computer to throw the check engine light and kick off tow/haul mode.
My questions are has anyone else experienced this issue? Should I install an upgraded aux tranny cooler that has the fan also or should I think about going up to a half ton or 3/4 ton diesel truck? I want to continue towing in the mountains but not sure if my 2.8 duramax is up to that task or not.

 

[DieselDrax]

Your issue was unrelated to the transmission temps, you need to connect a code reader and see if any permanent codes are stored. Trans temp will never throw a CEL before warning of high trans temp, which is triggered around 270F. 210F for trans temps while towing is just fine and isn't hot.

Something else is going on, need to find out what instead of throwing random parts at the truck without knowing why it's throwing codes.

 

[Hillbillyff]

Awesome advice thanks. Just went to Autozone and had them read the code. It is P228C Fuel pressure regulator 1 control performance-low pressure. Now to figure out why.

 

[DieselDrax]

Awesome advice thanks. Just went to Autozone and had them read the code. It is P228C Fuel pressure regulator 1 control performance-low pressure. Now to figure out why.

How many miles since you last replaced the fuel filters? What does the DIC say the fuel filter life % is at? If there's insufficient fuel flow under load caused by restricted filters then that can trigger that code. Might drive fine just cruising around or not towing but the fuel demand while towing, especially up grades, could be showing an issue with fuel flow. Replacing the fuel filters may be all you need to do, depending on how many miles it's been since they were last replaced.

 

[Hillbillyff]

How many miles since you last replaced the fuel filters? What does the DIC say the fuel filter life % is at? If there's insufficient fuel flow under load caused by restricted filters then that can trigger that code. Might drive fine just cruising around or not towing but the fuel demand while towing, especially up grades, could be showing an issue with fuel flow. Replacing the fuel filters may be all you need to do, depending on how many miles it's been since they were last replaced.

Yeah i had just replaced them recently, there is 96% left on them according to DIC.

 

[SFLTruck]

Yeah i had just replaced them recently, there is 96% left on them according to DIC.

I had a buddy of mine have a similar issue, only when towing and digging into the throttle pedal his truck would throw a code. It turned out to be algae growth in his fuel tank. It was limiting flow to the point under heavy loading it was dropping line pressure and throwing a code. Moral of that story is use a fuel additive or B20 if it's available once in a while to keep that from happening. I would still check the fuel filters (yourself) and even just swap them out as they're cheap enough. This way you can give them a visual inspection. Again a cheap test, run a few tanks of additive dosed fuel in the higher end of the mixing scale and see if that resolves the problem.

 

[Hillbillyff]

So i think I have figured out the issue. I had been using 0W20 oil instead of 5w30. I had researched and looked like it was ok to use. I think it has caused several issues. On my previous trip with the camper we were stuck for an extra day and i had to take it in to the dealer to get a service regen. On this latest trip also i had a warning as well saying low oil pressure and turn off the truck a few times. I think the 0w20 being thinner overall could have contributed to all these issues. I read that the code P228C is a generic code and also could be oil related so i will be changing back to 5 w 30 today.

 

[SFLTruck]

So i think I have figured out the issue. I had been using 0W20 oil instead of 5w30. I had researched and looked like it was ok to use. I think it has caused several issues. On my previous trip with the camper we were stuck for an extra day and i had to take it in to the dealer to get a service regen. On this latest trip also i had a warning as well saying low oil pressure and turn off the truck a few times. I think the 0w20 being thinner overall could have contributed to all these issues. I read that the code P228C is a generic code and also could be oil related so i will be changing back to 5 w 30 today.

I could see that causing low oil pressure, that 0w stuff is for the 3.0 inline LM2. The fuel rail pressure DTC still makes me wonder.....

 

[Hillbillyff]

Also i put this in my other thread but i have been using Dexos 1 Gen 2 instead of Dexos 2 the whole time i have owned this truck. Ugh the logo is confusing. Anyways i think that has played a role here also. I called a diesel shop and he said it should be ok as long as i just go back to the dexos 2 oil. Damn i gotta pay attention better that that.

 

[DieselDrax]

The dexos2 logo is blue, that makes it easy to differentiate. Yeah, GM really messed up with their stupid naming.

 

[Hillbillyff]

Thanks. Yeah i see that now. I saw the swoosh and the Gen 2 and thought it was Dexos 2. Fortunately my autozone has the dexos 2 and i just changed it.

 

[bigoilbob]

So we towed our camper through the Appalachian mountains this past week. On the way there and the way back towards the end of the trip the check engine light came on and locked the tow/haul mode off. Once the truck cooled after being off and not towing anymore then the light would go off and could resume tow/haul mode as needed. I had already previously installed a small aux cooler and it had def helped with keeping the tranny temps down they didnt get past 210 the whole trip but I think they averaged high enough for enough hours for the computer to throw the check engine light and kick off tow/haul mode.
My questions are has anyone else experienced this issue? Should I install an upgraded aux tranny cooler that has the fan also or should I think about going up to a half ton or 3/4 ton diesel truck? I want to continue towing in the mountains but not sure if my 2.8 duramax is up to that task or not.

Yes. In our case it was a bad EGT. But I would get it coded, per DD. I would stay stock and keep towing.