Getting a code after my tuner was installed

[Lb7x2]

Hello. Just got a couple questions for anyone who can answer them, I’ll start from the beginning.
I recently installed a dsp5 switch in my 2001 LB7. Had brought it to a guy who flashed 5 tunes on my ecm. On the ride home my truck went into “limp mode” so I pulled over, let the truck sit for a minute, and restarted the truck. It was back to normal. Well just within the past 4 or 5 days I’ve had my service engine light on and noticed when I’d shut my truck off and start it for work the next day it would be in “limp mode”.. so Id have to stop up the road shut it off turn it on and it’s good... until next time. I brought it to a local mechanic today who plugged in his scanner and the only code Its bringing up is (P1781 Engine Torque Signal or Transmission MIL Request). Yesterday and today I’ve noticed now it is starting to shift hard into and out of gear. Anyone else have this issue before or could tell me what is going on? All of this happened in sequence to how I explained above.
Thanks!

 

[2004LB7]

See here

LB7: - Trans Limp and P1781 / P0700 under load acceleration

Hi Folks. Hoping someone out there can help with my issue... Haven't found much info out there on the interwebs... Here's the scoop: Truck is a 2002 Duramax with Allison and 293K on the clock. Trans was rebuilt in May (maybe 20k on it since). I have a SuperChips DashPaq tuner on it for...

www.duramaxdiesels.com

 

[Lb7x2]

Couldn’t find an exact diagnosis on that post. My truck seems to be acting a bit different but thanks for the reply

 

[2004LB7]

Read through and do what is mentioned in post #10

 

[Lb7x2]

Read through and do what is mentioned in post #10

Okay thanks! I’ll check that tomorrow!

 

[Lb7x2]

Read through and do what is mentioned in post #10

How do I locate the wire from the ecm to the tcm? Do you know which PIN number it would be?

 

[2004LB7]

This is from that post

"Referencing the 03 FSM, assuming 02 is same: there are 2 +12v power pins on the TCM that come from the ignition switch, C1-2 and C1-4 (pink wires) and one +12v always hot from the battery at C1-3. C1-1 and C1-5 are grounds (black wire with white trace). Manual is not super clear here, but it appears that the TCM ground pins tie into the ground point G102, which is on the right side of the engine block, just in front of the starter."

 

[dndj]

Post above covers the TCM power and ground circuits. The single wire circuit associated with P1781 which the TCM requests MIL to the ECM is C1 pin 25 on the TCM and C2 pin 53 on the ECM - dark blue wire. This is info for the GMT800 03-07, I know there are some differences in the 01-02 trucks so keep that in mind.

I would put the ECM tuning back to stock and see if the problem goes away. My guesses are wrong base OS was used in the tunes (who's tunes BTW?) or a possible wiring issue when the DSP switch was installed.