When is a full flash needed?

[cagedup]

Hey guys for about 8 months I've been getting into tuning and trying to learn it the best I can on my on. My question is when is a full flash needed. I've helped several of my friends with there tunes and I never had to do a full flash. Just curious. Thanks


Sent from the back 40

[ScarabEpic22]

Depends what PCM/ECM/TCM we're talking about. Some, like the Cummins ECMs, need to be full flashed every time. Most GM vehicles only need to be full flashed IF you're upgrading to a COS/patching the OS. Most Duramax ECMs only need to be full flashed when going to DSPx, then cal flashes (LB7/LLY I believe needs to be full flashed to change some of the tunes).

[cagedup]

I'm only talking about late model GM gas engines. I was thinking it had something upgrading the OS but wasn't completely sure.


Sent from the back 40

[ScarabEpic22]

Gen IV stuff, only if there is an OS patch or COS upgrade being applied.

[cagedup]

Cool thanks man


Sent from the back 40

[GMPX]

Erik is correct on late GM ECM's, it is a misconception that a full flash is needed to correct tuning problems or remove gremlins from the tune.

[joecar]

Gen III: if changing OS's, or if enabling LC via cax.