Dtc U0115 & U0100 - Diesel Forum

2008GoldThunder · 10-01-2009, 10:34 AM

Anyone experience having DTC: U0115 & U100 [U0115 Lost Communication with ECM/PCM B & U0100 Lost Communication with ECM/PCM A]? How did you get this issue resolved?? As a side note, I had just upgraded my SCT Livewire to the Extreme version and had been operating normally for the last 10 days or so [with Extreme tune set]. I appreciate any insight possible before heading to the dealership. Thank you!

Sincerely,
2008 Gold Thunder

senix · 10-02-2009, 09:16 AM

my guess would be your tuner is having a conflict. Try clearing the codes and take it back to stock and run it awhile. Then go from there. Almost sounds like your PCM is toast.

2008GoldThunder · 10-02-2009, 01:36 PM

SENIX,
Thanks for your response! I cleared the codes, but they come back upon the next startup. The SCT rep stated that the truck will clear the codes after a series of starts [10-20] and 60-80 miles driven. I had none of these issues with the Livewire basic programmer tunes. However, SCT rep also stated that these communication error codes have to do with applying the "new" tunes; not everyone experiences this issue apparently. With regard to you saying that my PCM might be toast, then wouldn't the truck not run. Currently, my truck is operating normally except with the CEL showing.

Sincerely,
2008 Gold Thunder

senix · 10-02-2009, 03:47 PM

What I mean't was there maybe an issue with the pcm itself. But with the additional info you provided it does appear to be with your tuner. Sounds like you are on track to get it figured out with the SCT Rep.

1jeep · 01-24-2010, 01:25 PM

ok, i am running a sct also and just got these codes after changing my fuel filters. Also if i cycle my truck per the maunal for the 6 times i can get teh truck to start but then it dies and wont start again.

Any ideas?

senix · 01-24-2010, 01:33 PM

Quote:

Originally Posted by 1jeep

ok, i am running a sct also and just got these codes after changing my fuel filters. Also if i cycle my truck per the maunal for the 6 times i can get teh truck to start but then it dies and wont start again.

Any ideas?

Still air in the system. You could try and hold down the fuel cutoff switch while cranking, located on the passenger side dash. Open the door and you will see the access door. Hold it down while cranking. Works for me.

1jeep · 01-24-2010, 01:42 PM

tried that, but i will try again, i can only get the truck to start and then die after 20 seconds. I also get the nice little wrench display.

I just tried setting my tune back to stock and still the same, back to try the fuel cut off.

1jeep · 01-24-2010, 01:55 PM

do you crank the engine while holding down the fuel cut off or just power cycle it?

senix · 01-24-2010, 02:15 PM

Quote:

Originally Posted by 1jeep

do you crank the engine while holding down the fuel cut off or just power cycle it?

I held mine down while cranking.

1jeep · 01-24-2010, 02:33 PM

mine stops cranking if i do that

triplee44 · 01-27-2010, 02:23 PM

Quote:

Originally Posted by 2008GoldThunder

Anyone experience having DTC: U0115 & U100 [U0115 Lost Communication with ECM/PCM B & U0100 Lost Communication with ECM/PCM A]? How did you get this issue resolved?? As a side note, I had just upgraded my SCT Livewire to the Extreme version and had been operating normally for the last 10 days or so [with Extreme tune set]. I appreciate any insight possible before heading to the dealership. Thank you!

Sincerely,
2008 Gold Thunder

I had the exact same problem. I posted the whole situation on another site. Basically, you have to tune it to "trans only" a bunch and eventually it will run correctly. I have talked to Rudy's, and Matt from SCT. The same day that it happened to me, it happened to 3 other people I believe. I'm being told that they're working on it but nothing yet.