Fuel Trim

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Feb 28, 2022 | 05:14 PM

Swens

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From: Tucson, AZ.

Fuel Trim

I've worked with a lot of scan tools over the years. On the German brands when a hard fault is cleared the short and long term fuel trims were reset automatically.
It was good to see an immediate change in short term trim after a related repair.
With our cars is the same true? A fault clear via the DIS or scan tool, or a manual reset? Or at all?
I just replaced all of my hardened injector seals. The engine runs smoother for sure. Just would be nice to confirm the change and by how much.

Mar 1, 2022 | 07:48 PM

C5MSG2004Vert

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From: New Jersey

Quote:

Originally Posted by Swens

When my C5 has problems with the fuel trims because of a Vararam install. I thought resetting the codes from the DIC reset the fuel trims but that's not true. Just checked it

Last edited by C5MSG2004Vert; Mar 1, 2022 at 11:35 PM.

Mar 1, 2022 | 08:23 PM

C5 Diag

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From: Cape Coral, Florida

The fuel trims will not reset if a DTC is cleared…if you have a decent scan tool you should have a “fuel trim reset” usually under “special functions”.

Mar 1, 2022 | 08:24 PM

Swens

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From: Tucson, AZ.

Quote:

Originally Posted by C5 Diag

The fuel trims will not reset if a DTC is cleared…if you have a decent scan tool you should have a “fuel trim reset” usually under “special functions”.

Would love to have one.

Mar 1, 2022 | 11:40 PM

C5MSG2004Vert

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From: New Jersey

Quote:

Originally Posted by Swens

Would love to have one.

If you need to reset the LTFTs just disconnect the battery for a few minutes. After removing the battery cables you can touch the cables together to assure all voltage has been removed from the PCM.

Mar 8, 2022 | 12:12 AM

douglasjre

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Quote:

Originally Posted by C5MSG2004Vert

If you need to reset the LTFTs just disconnect the battery for a few minutes. After removing the battery cables you can touch the cables together to assure all voltage has been removed from the PCM.

Would this reset the radio so it no longer works