Negative spark advance at throttle tip in. Why?

[rossp]

This problem left me stranded the other day. I got my efi live scan tool hooked up and I noticed the timing going to -20 at throttle tip in. The truck will only idle. With any throttle input it is pulling a ton of timing. I happened to unplug the tps and the truck is drivable. I can't seem to figure out why all of a sudden it started doing this. I have attached a tune and log file.

[rossp]

A little more insight to this problem. This has happened on two separate occasions. Both times on a whim I have reflashed the pcm and the problem has dissapeared for a few days. This really concerns me as I do not want to end up stranded because of this. Does anyone have any insight into this.

[swingtan]

{B5915} is currently set to -20, so that's where the minimum timing is coming from.

{A001} and {A002} were both detected as "out of range", and checking the rest of the tune shows a number of torque management tables are also out of range. {B1901}, {B6611} for example. It's very possible that the out of range tables are causing the ECM to randomly pull timing. I'd go through the tune and ensure any table listed as out of range is set correctly. For "%" tables 100% should be OK, for other tables like torque limits, set them '1" below the listed maximum.

Simon.