08 LMM duramax TPS reading

[c5forfun]

2008 Chevrolet 3500 duramax reduced power keeps popping up randomly. 160k on truck, NO CODE comes up. However while driving and logging data, I can clear the "reduced engine power" by clearing all DTC's even though HP tuners is not showing any code?
Some times it comes back in one to two seconds, I can clear it again and it will go for days without coming back?
very frustrating. I have searched and searched but not getting any real good information.

Does anyone know if the TPS reading in HPtuners scanning should be static at 13.7 (once in a while it will jump down to 13.3) if it is reading TPS it should be moving around with throttle position I would think?

The throttle pedal was replaced at one point by previous owner. I have been trying to figure out which wire sends tps information that I am seeing while scanning but no luck yet.
MAF has been replaced.

Is there a separate TPS on the intake? I have searched the internet but have not found anything for a diesel tps other than some sites have tps/app as the accelerator peddle assembly. Are they both located there?

Thanks

[gtstorey]

Have you checked to see what DTC's are disabled in the tune? I have an overboost code disabled in mine (totally different GM vehicle) that will still cause it to reduce boost but doesn't turn on the MIL light or register the code. It will self clear after a restart though with the code off.

[TheMechanic]

You need a more advanced scan tool so you can scan additional modules that can have codes but NOT in the ECM. Such as GPCM

[c5forfun]

This truck is all original and stock, but i will see if there are any DTC's that are disabled, thanks for the idea.

I have used another scan tool Autocel, that did pull up codes in history, which is all associated to items he had changed out.
Why doesn't HP tuners pull up codes from history?

Any ideas on why HPtuners is logging TPS as static at 13.7? if a diesel uses tps, then I understand why it is logged, but i cannot find anything about TPS for diesels?

[gtstorey]

Hpt only interfaces with certain modules ECM/transmission/fuel pump and I don’t know that it can talk to the trans and fuel pump on everything. So there maybe other modules that see a problem. I would think a Reduced Power would at least show up in the ECM.

I don’t know enough about the diesel to speculate on the throttle. And there are often multiple throttle channels that will read different from each other.

[Stroked06Goat]

I'll take a look at my 2010 log when i get my tuning laptop out. Its probably normal if had to guess at that number.

[c5forfun]

I'll take a look at my 2010 log when i get my tuning laptop out. Its probably normal if had to guess at that number.

thanks