All of a sudden the truck started acting like it had a miss

[mulcher812]

So while out running some errands today all of a sudden my truck started acting like it had a miss. I limped it home and pulled the codes to find a P0602 - ECM fueling calibration error. I cleared the code reset the ecm to stock settings and started the truck up and it's still there. I reprogrammed the truck to lvl 6 started it back up and still no change. Is there a way to check if its VP or the ECM? Thanks in advance to the help everyone.

[Mopar1973Man]

P0602 is a Smarty thing.

 

Now if the error code comes back while stock then you might want to read over the error code.

http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/59-obdii-error-codes-cummins/203-p0602-ecm-fueling-calibration

[mulcher812]

Thanks Mike thats where I started with that info and returned everything to stock from the smarty but it was still there. I'm going to try and do a battery disconnect and reset to see if this changes anything.

[Mopar1973Man]

Battery disconnect does nothing. All you need to do is turn your key OFF to reset the computers. Even time you turn the key ON the computers do a fresh reboot. This tells me the ECM does indeed have internal issues and should consider re-flashing the ECM with true stock software and seeing if that fixes it. If not the on-board flash PROM is damaged and not holding data properly.

[mulcher812]

Ok so I somehow managed to clear the code but the rpm's are still surging and the truck isn't feeling correct.

[TFaoro]

Fuel pressure? Miles on VP? Is it one cylinder or many?

[mulcher812]

Fuel pressure is 18 at idle and 16 at wot. VP has about 120k on it. I used a modis and shut off each cylinder and it changes but once returned to operating it doesn't fix the rough idle.