Manufacturer communication — 2006 GMC YUKON DENALI XL

• 2006-2013 GM passenger cars and light duty trucks with V8 gasoline engines only.

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  2006-2013 GM Passenger Cars and Light Duty Trucks Equipped with V8 Gasoline Powered Engines Only

• GM is seeing a growing number of engine, transmission and catalytic converter part failures caused by non-GM (aftermarket) engine and transmission control calibrations.

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  General Motors is identifying an increasing number of engine, transmission and catalytic converter part failures that are the result of non-GM (aftermarket) engine and transmission control calibrations being used.

Possible causes

• Altering the GM-released calibrations subjects the engine, transmission, transfer case, driveshaft and rear axle to stresses GM did not test.

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  When alteration to the GM-released engine or transmission control calibrations occurs, it subjects powertrain and driveline components (engine , transmission, transfer case, driveshaft and rear axle) to stresses that were not tested by General Motors.

Steps to confirm (in the document’s order)

1. Check for a non-GM calibration whenever a hard part failure is seen on internal engine, transmission, transfer case or rear axle components, and before disassembly, repair or replacement of those assemblies under warranty.

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   GM recommends performing this check whenever a hard part failure is seen on internal engine, transmission, transfer case or rear axle components, and before disassembly, repair or replacement of an engine, transmission, transfer case or rear axle assembly under warranty.

2. The engine calibration verification is also recommended whenever diagnosis calls for catalytic converter replacement.

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   It is also recommended that the engine calibration verification procedure be performed whenever diagnostics determine that catalytic converter replacement is necessary.

3. With the Tech 2, photograph the Vehicle Information screen showing the entire VIN, the (Engine) Calibration ID and the Verification No.

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   Take a CLEAR digital picture of the Tech 2® Vehicle Information screen showing the entire VIN, (Engine) Calibration ID and Verification No. (Numbers).

4. If the Tech 2 shows all zeroes for the Verification Numbers, update the Tech 2 with the latest software from TIS2WEB.

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   If the Tech 2® that you are using displays all zeroes for the Verification Numbers as shown, then perform the following steps: 1. Update the Tech 2® with the latest software from TIS2WEB.