Servo Motor for Variable Vane turbo

[JohnnyR]

How do you tell if the servo motor for the variable vane turbo on an '05 LLY is working correctly? Will it set an error code?

[More Power]

You can read more about the LLY and VNT trouble codes here (http://www.thedieselpage.com/duramax/lly2004.htm). :)

Jim

[JohnnyR]

Thanks for the info, Jim. I read this some tiime ago and forgot about it. Do I assume correctly that if I had a servo motor problem, an error code cited in the article would be showing up w/an OBD tool or on the DIC?

[More Power]

If the problem is producing a drive-ability issue, it should produce a code viewable via an OBD II reader.

Jim

[JohnnyR]

Thanks again, Jim.
Only issue per say is that it smokes heavily when you floor it, and fuel mileage dropped a little. Had them plug a code reader in at Autozone but nothing showed up.

[More Power]

Change the fuel filter and verify that the air filter is clean. If you're using an aftermarket oiled-gauze or oiled-foam air filter element, I'd want to clean the MAF sensor using an automotive spray solvent.

If the problem is still there, and assuming you're not using some sort of performance program, you may want to schedule a visit with your local GM dealer service department. Mention your concern about heavy black smoke, and suggest they evaluate the VNT and EGR. Both systems can be "exercised" with a Tech II to verify proper operation.

Jim