Manufacturer communication — 2006 GMC YUKON DENALI XL

• Applies to 1999-2013 GMC Savana, Sierra and Yukon.

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  1999-2013 GMC Savana, Sierra, Yukon

• Applies to vehicles with a V-8 gas engine.

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  with a V-8 Gas Engine

• A slight rough idle with no DTCs or other engine performance concerns; comparison vehicles may show the same concern.

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  Some customers may complain of a slight rough idle with no DTCs or additional engine performance concerns and comparison vehicles may exhibit the same concern.

• In some instances an occasional misfire may register on the Tech 2 at idle, but no DTCs will be stored.

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  In some instances, an occasional misfire may also register on the Tech 2 when the engine is idling but no DTCs will be stored.

Steps to confirm (in the document’s order)

• Compare the concern to a like vehicle; if it is worse than the like vehicle, complete SI diagnosis and repair as necessary.

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  Compare the concern to a like vehicle. If the concern is worse than a like vehicle, complete SI diagnosis and repair as necessary.

Caution

• If SI diagnosis for Rough, Unstable, or Incorrect Idle is inconclusive, or the concern is the same as the like vehicle, consider it an idle characteristic of the vehicle and attempt no repairs.

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  If SI diagnosis for Rough, Unstable, or Incorrect Idle have been completed and are inconclusive or if the concern is the same as the like vehicle, this should be considered an idle characteristic of the vehicle and no repairs should be attempted.