Pulling timing but not sure where?

[02sierra4x4]

We have a 5.3L, 12587603OS we are trying to find where our commanded timing is getting skewed. Seems to be pulling 3 degrees above 4000rpm but only at WOT or close to. We have been through all the standard tables, IAT, ECT, Ethanol,Torque management, Fuel Mixture Corr. ETC. We went to a COS to see if that would help, still the same. Any help would be appreciated. See calibration below, Thanks:mrgreen:

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[joecar]

Log the pids GM.EST_xxxx_DMA these may give a clue as to what is pulling timing

( EST = electronic spark timing )

[02sierra4x4]

We have and have not seen anything register as far as retarding the timing. I will post the log in the original post. thanks for the reply!!

Brandon

[joecar]

Also look carefully at the spark modifier tables in the tune.

And also the burst knock tables.

[02sierra4x4]

Also look carefully at the spark modifier tables in the tune.

And also the burst knock tables.

We will recheck all of the modifiers, we have zeroed out the burst knock tables but will see what those modifiers look like as well and retest, thank you.

Brandon

[02sierra4x4]

We verified all modifiers are zeroed out and checked burst knock again at least what we know to check. Here is the log with the modifiers zeroed out.

Brandon

Here is the log

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[joecar]

hmmm... try doing a full flash.

[02sierra4x4]

hmmm... try doing a full flash.Tried full flashing it a few times, no luck. we are trying an operating system with different segment calibrations in hopes for a different outcome.

Sent from my SM-G930V using Tapatalk

[02sierra4x4]

Tried different segments, still no change.

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Is there any cons to changing operating system to one that is similar to the one pulled from the PCM??

thanks to all who have gave it some thought,

Brandon