Customer Satisfaction-Transmission Overheat in Extreme Cold Ambient Temperatures-Reprogram TCM

Certain 2006-07 Chevrolet Silverado HD and GMC Sierra HD model vehicles, located in Alaska; and Canadian Yukon and Northwest Territories only, and equipped with an Allison 1000 Transmission (RPO MW7) and Duramax 6.6L Diesel V8 (RPOs LLY/LBZ/LMM - VINs 2/D/6) engine, may have limited or no transmission fluid (oil) flow through the transmission oil cooler after sitting for an extended period of time, such as over night, during extreme cold temperatures, less than -40 °F or °C. If the "Elevated Idle Mode", cabin heater performance option is operative and the engine is allowed to idle for an extended period of 15 to 30 minutes while cooler flow is limited, the transmission fluid may overheat, resulting in transmission damage, and subsequent failure.

Dealers are to reprogram the Transmission Control Module (TCM).

Involved are certain 2006-07 Chevrolet Silverado HD and GMC Sierra HD model vehicles, located in Alaska; and Canadian Yukon and Northwest Territories only, and equipped with Allison 1000 Transmission (RPO MW7) and Duramax 6.6L Diesel V8 (RPOs LLY/LBZ/LMM - VINs 2/D/6) engine and built within these VIN breakpoints:

Important: Dealers are to confirm vehicle eligibility prior to beginning repairs by using the GM Vehicle Inquiry System (GMVIS). Not all vehicles within the above breakpoints may be involved.

For dealers with involved vehicles, a listing with involved vehicles containing the complete vehicle identification number, customer name, and address information has been prepared and will be provided through the applicable system listed below. Dealers will not have a report available if they have no involved vehicles currently assigned.

-- US GM - GM DealerWorld Recall Information

-- Canadian GM dealers - GMinfoNet Recall Reports

The listing may contain customer names and addresses obtained from Motor Vehicle Registration Records. The use of such motor vehicle registration data for any purpose other than follow-up necessary to complete this program is a violation of law in several states/provinces/countries. Accordingly, you are urged to limit the use of this report to the follow-up necessary to complete this program.

Do not attempt to order the calibration number from GMSPO. The calibration numbers required for this service procedure are programmed into control modules via a Techline Tech 2® scan tool and TIS 2 WEB website with the following calibration updates:

2006-07 Chevrolet Silverado HD and GMC Sierra HD: Use data version 12.5 for 2007 or later, available on TIS 2 Web 12/17/07 .

If you cannot access the calibration, call the Techline Customer Support Center and it will be provided.

Notice: Due to the time requirements of programming a controller, it is recommended that an external power source be used to maintain system voltage. Stable battery voltage is critical during programming. Any fluctuation, spiking, over voltage or loss of voltage will interrupt programming. To ensure trouble-free programming, GM recommends using one of the following external power sources:

The ignition switch must be in the proper position. The Tech 2® prompts you to turn ON the ignition, with the engine OFF. DO NOT change the position of the ignition switch during the programming procedure, unless instructed to do so.

Make certain all tool connections are secure, including the following components and circuits:

DO NOT disturb the tool harnesses while programming. If an interruption occurs during the programming procedure, programming failure or control module damage may occur.

DO NOT turn OFF the ignition if the programming procedure is interrupted or unsuccessful. Ensure that all control module and DLC connections are secure and the TIS terminal operating software is up to date.

Refer to the appropriate service procedure in SI to Reprogram the Transmission Control Module (TCM) Operating System and Calibration.

All customer requests for reimbursement for previous repairs for the condition will be handled by the Customer Assistance Center, not by dealers.

A General Motors Customer Reimbursement Procedure and Claim Form is included with the customer letter.

Important: (For GM Only) Refer to the GM Service Policies and Procedures Manual, section 6.1.12, for specific procedures regarding customer reimbursement and the form.

Customer requests for reimbursement for previous repairs for the condition are to be submitted to the dealer by December 31, 2008.

All reasonable customer paid receipts should be considered for reimbursement. The amount to be reimbursed will be limited to the amount the repair would have cost if completed by an authorized General Motors dealer.

When a customer requests reimbursement, they must provide the following:

Claims for customer reimbursement on previously paid repairs are to be submitted as required by WINS.

Important: Refer to the GM Service Policies and Procedures Manual, section 6.1.12, for specific procedures regarding customer reimbursement verification.

The General Motors Courtesy Transportation program is intended to minimize customer inconvenience when a vehicle requires a repair that is covered by the New Vehicle Limited Warranty. The availability of courtesy transportation to customers whose vehicles are within the warranty coverage period and involved in a product program is very important in maintaining customer satisfaction. Dealers are to ensure that these customers understand that shuttle service or some other form of courtesy transportation is available and will be provided at no charge. GM Dealers should refer to the General Motors Service Policies and Procedures Manual for Courtesy Transportation guidelines.

Submit a Product Claim with the information indicated below:

Refer to the General Motors WINS Claims Processing Manual for details on Product Recall Claim Submission.

General Motors will notify customers of this program on their vehicle (see copy of customer letter included with this bulletin).

All unsold new vehicles in dealers' possession and subject to this program must be held and inspected/repaired per the service procedure of this program bulletin before customers take possession of these vehicles.

Dealers are to service all vehicles subject to this program at no charge to customers, regardless of mileage, age of vehicle, or ownership, from this time forward.

Customers who have recently purchased vehicles sold from your vehicle inventory, and for which there is no customer information indicated on the dealer listing, are to be contacted by the dealer. Arrangements are to be made to make the required correction according to the instructions contained in this bulletin. A copy of the customer letter is provided in this bulletin for your use in contacting customers. Program follow-up cards should not be used for this purpose, since the customer may not as yet have received the notification letter.

In summary, whenever a vehicle subject to this program enters your vehicle inventory, or is in your dealership for service in the future, you must take the steps necessary to be sure the program correction has been made before selling or releasing the vehicle.

Dear General Motors Customer:

We have learned that your vehicle may have limited or no transmission fluid (oil) flow through the transmission oil cooler after sitting for an extended period of time, such as overnight, during extreme cold temperatures -40 °F or °C or less. If the "Elevated Idle Mode" cabin heater performance option is operative and the engine is allowed to idle for an extended period of 15 to 30 minutes while cooler flow is limited, the transmission fluid may overheat, resulting in transmission damage, and subsequent failure.

Your satisfaction with your 2006-07 Chevrolet Silverado HD or GMC Sierra HD pick up truck is very important to us, so we are announcing a program to prevent this condition or, if it has occurred, to fix it.

What We Will Do: To prevent this condition from occurring, your GM dealer will reprogram the Transmission Control Module (TCM). This service will be performed for you at no charge.

What You Should Do: To limit any possible inconvenience, we recommend that you contact your dealer as soon as possible to schedule an appointment for this repair.

This is not the same reprogramming that we offered to customers in 2006. You should have this new reprogramming completed even if the earlier reprogramming was completed, and GM will reimburse you for the cost of the earlier reprogramming.

Customer Reply Form: The enclosed customer reply form identifies your vehicle. Presentation of this form to your dealer will assist in making the necessary correction in the shortest possible time. If you no longer own this vehicle, please let us know by completing the form and mailing it back to us.

Reimbursement: If you paid for TCM reprogramming for this condition before December 2007, GM will reimburse you for the reprogramming cost. The enclosed form explains what reimbursement is available and how to request reimbursement if you have paid for repairs for this condition.

If you have any questions or need any assistance, just contact your dealer or the appropriate Customer Assistance Center at the number listed below. The Customer Assistance Center’s hours of operation are from 8:00 AM to 11:00 PM, EST, Monday through Friday.

Courtesy Transportation: If your vehicle is within the New Vehicle Limited Warranty your dealer may provide you with shuttle service or some other form of courtesy transportation while your vehicle is at the dealership for this repair. Please refer to your Owner’s Manual and your dealer for details on courtesy transportation.

We sincerely regret any inconvenience or concern that this situation may cause you. We want you to know that we will do our best, throughout your ownership experience, to ensure that your GM vehicle provides you many miles of enjoyable driving.

Scott Lawson

General Director,

Customer and Relationship Services

Enclosure

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