Other night the truck did a regeneration.
The next morning the check engine indicator light came on, manual says it concerns the exhaust emissions (not a check engine light I guess).
I opened up the OBDLink EX that I had bought recently.
Installed the FORScanSetup2.3.37.beta*****
Followed the directions to read the onboard computer:

===PCM DTC P244A:00-EC===
Code: P244A - Particulate Filter Differential Pressure Too Low (Bank 1)
Status:
- DTC Maturing - Intermittent at Time of Request
- Malfunction Indicator Lamp is On for this DTC
- Test not complete
...
===END PCM DTC P244A:00-EC===

===OBDII DTC P244A-C===
Code: P244A - Particulate Filter Differential Pressure Too Low (Bank 1)
Status:
- Confirmed - malfunction is confirmed
Module: On Board Diagnostic II
===END OBDII DTC P244A-C===

I wanted to leave the indicator light tripped so when the service technician takes a look at the vehicle.
The product says it is capable of resetting the indicator light, but I only had it connect and read the current state.
After I disconnected the OBDII EX adapter, I turned the key over and the indicator light was still tripped.
Our other vehicle is in the shop and supposed to pick it up tonight, so I have not had the truck into the shop yet.
In the meantime my wife drove the truck to work a few times ~ additional 30 miles total.
Today I noticed the indicator light is no longer on. The particulate filter percentage is back up to 40%, in-town driving.

Why would the indicator light go out? Would the truck's computer auto reset it?

thanks

 

If the fault is intermittent and the truck goes through a defined set of restarts with no fault, it will turn off the light. However, the code should still be stored unless you reset it. I had the same issue with NoX sensor, light turned off, code was still there, on the way to dealer light turned back on, which made it even easier. But even with light off code is still stored for diagnoses.

 

I haven't taken it to the service center yet.

truck went through another regeneration, it was at 65% so I was not watching or expecting a regeneration and I was only on the highway for a few exits, got to my destination and went to shut the truck off when I noticed it say 25%, the light did not come on, wondering if it needs to get down to 0% before that same error would trip

 

Went through another regeneration, then two months while not doing a regeneration the check engine light came on during startup.
We were moving and the OBDLink cable is in the storage unit somewhere, so I haven't looked yet to see that it is the same error, but I expect it is.
Two more regenerations, the first was my wife driving and she said it took the normal time, the latest I was driving and it took long like I mention in the initial post, but this time it was hot summer out.
Now that are settled I climbed under the vehicle and was looking around the front DPF parts found a sensor cable torn.
Where we lived vehicles would occasionally have wires chewed by some animal, probably field mice, especially if it sat for any length of time, which this did.
In any case, is this a sensor cable I can replace myself?
If so, how do I find the part number to order it?
or should I take it to the dealership and tell them what I want done?

 

Probably have to replace the whole sensor. If an animal chewed it, your insurance might cover it, although may be below the deductible.