2009 g8 gxp

[jah81592]

Anyone had the issue of the trims showing 0 (zero-flat line) while on the dyno. But when you get on the street they act properly. I suspect that it is something tied into the traction control. -j

[joecar]

Is PE enabling while on the dyno...?

Post a log from the dyno.

[jah81592]

I don't think so. The reason i say that is I have tuned tons of E38 vehicles and no issues so far. It occurs once the tires turn over and the traction control/stability trac comes on. After that i get a flat line. I don't have any load on the roll at this moment. So...I would suspect that we are not in PE mode. I will post a file later. Thanks for your assistance so far. Oh yeah- did this with the bone stock tune as well.-j

[jah81592]

Here ya go. This is a completely bone stock unflashed tune. This is the way it came from GM.

[ScarabEpic22]

Here ya go. This is a completely bone stock unflashed tune. This is the way it came from GM.

That a log file, not a tune.

[jah81592]

Exactly, this is a 100% stock vehicle that it was doing this with. I was asked to post a log file. Here is the stock tune file. It doesn't matter tuned or untuned it does it.-j

[joecar]

In that log file, are you referring to where advance drops down into those zero spikes...?

[swingtan]

I think it's the STFT's disabling, which I also think is the TC activating. Do the US based cars have the ability to turn off TC via a button, or is it just via the tune?

[joecar]

US cars usually have a switch to turn off TCS.

[jah81592]

I cannot explain why the fuel trims zero out. It is only happening on the dyno. Stock or tuned.

[swingtan]

Any chance that your constant knock is causing STFT to disable? I've rarely seen an engine knock so consistently.......

Simon.