I was towing from Montrose to Gunnison CO (14500 lb 5th wheel). 2020 6.7L in tow mode with engine brake set to auto. Had just crested a peak going very slow (road construction, going 20-25 mph) - truck went into 2nd gear, was at 3500+ RPM as we started to descend. Then I got the “reduced engine power” message and the truck went up a couple of gears.

As we got to the bottom of the grade I had very little power and the tranny went to 9th gear. I could not get past about 25 mph up the next grade.

Then at the top (post road construction) I tried to accelerate going down grade. Tranny was picking high gears and engine breaking was non existent. I got to about 65 mph and then started getting more “reduced engine messages” - I was on a steep downgrade again. Drove about 15 miles until I could pull off the road.

I pulled out my code reader and it showed a P062B - no other DTCs. No check engine light ever showed up either.

I reset the P062B DTC and power cycled the engine. No more codes and the truck ran fine the rest of the day pulling - up and down mountain passes.

I had about 1/2 tank diesel, DEF is 1/2 full. I have less than 7K miles on the truck. Before the trip I opened the diesel fuel drain (no water in fuel).

What happened???

 

Over temperatures ?

 

No not at all. It was 50 degrees out and the truck was at 192 engine and 202 transmission.

I pulled the Rockies the other day and went up the side of I70 to the Eisenhower tunnel going 60-64 with plenty of pedal to spare. Those temps were in the 215 range and tranny was about 225 peak. It was much hotter 90’s to near 100.

 

You would be in a better position had you not cleared the code. When you clear the code, you also clear the freeze frame data. If you now take your truck to the dealer to figure out what happened, they'll tell you nothing happened since there's no code and no freeze frame data and send you on your way.

Clearing a code does not ever fix a problem. The computer doesn't work that way. It just means you start over again. If whatever set the code resolved, the MIL will self extinguish usually after a couple drive cycles. Whatever set the code still exists and it will happen again. If you had not cleared the code, it would exist in history and the freeze frame data would still be there. The dealer could troubleshoot the problem with that.

Hopefully it's just a reflash thing so it may be worth going to the dealer with the code and they might have a TSB on the problem.

 

If it happens again I won’t clear the code. If it never happens again then probably a one-time extreme condition that triggered it. There were no other DTCs and no CEL.

Very dangerous when towing …

 

One way to make sure you need a tow is to keep driving in the reduced power mode. That's so you can get it to the side of the road.....

 

Google only takes about 5 seconds to give an answer on that. "P062B Internal Control Module Fuel Injector Control Performance"

You are right however, when the truck identified an issue, and you choose to just clear the code and continue towing in the mountains, it was very dangerous.

 

Sounded like he was in the mountains and found a place to pull over eventually, I wouldn’t stop either. Not like oil was pouring out and smoke everywhere..

 

It will need at least a reflash to see if there is an issue with the injectors.

 

Today I saw in Ford Pass that the truck gave 3 warnings that the Diesel Particulate Filter needed cleaning and is full - timed exactly when the Reduced Engine Power messages appeared. Each message time stamped to when the issue occurred. I am thinking the code P062B was something different because I never had a check engine light and it was pending.

The prior 3 days we had been driving around Colorado solo (not towing). I have the display of DPF turned on and never noticed it get above 40%, but I was not paying attention that morning because when towing the DPF% usually goes to zero.

We finished the rest of the trip with no issues (NM, Texas - Big Bend, back through AR, KY, WV and MD). Several thousand more miles towing for a total of 5800 miles.

 

You did the right thing. Damn trucks get frustrating. Mine ran out of fuel with 50mi to empty.

 

Guess I don’t quite follow this dpf cleaning issue.
I thought keeping the DEF from going empty was supposed to regen and “clean” the dpf. Am I missing something here? Are we supposed to regularly take the truck in and have the dpf cleaned?
Troy

 

The Diesel Exhaust Fluid (DEF) and Diesel Particulate Filter (DPF) are two different unrelated systems for two different purposes. DEF fluid reduces NOx emissions. The DPF filter catches soot. Once the DPF filter gets full of soot to a certain level the truck uses extra fuel to increase the exhaust temperature and finish burning that soot into ash and clear it out. The truck does this as needed without input from the driver.

 

But the dpf process can screw u if it happens on a hill. The truck runs weird. Loses power. I dont know why the upper trims dont have a manual regen.

 

Ahhhh. I thought the DEF was there to heat up the exhaust to burn the soot off the DPF. So what does the def have to do with a regen? Does the exhaust regen for dpf and the def? Confusing. And yes, I have actually tried reading about this and can’t get it straight.
Troy