Customer Satisfaction - Transmission Performance-Reprogram Computer Module

*********THIS PROGRAM IS IN EFFECT UNTIL AUGUST 31, 2008.**********

On certain 2007 four-wheel drive Chevrolet Silverado and GMC Sierra vehicles, the combination of the 4.10 ratio axle gear sets and the body control module (BCM) calibration could cause vibration in the driveline. This vibration could crack the transmission housing or transfer case adapter, reducing the performance of the transmission.

Dealers are to reprogram the BCM to attain highway speeds of up to 138 km/h (86 mph).

Involved are certain 2007 Chevrolet Silverado and GMC Sierra vehicles 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 GMinfoNet Recall Reports. Dealers will not have a report available if they have no involved vehicles currently assigned.

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.

No parts are required for this program.

IMPORTANT CALIBRATION INFORMATION

Contact the Techline Customer Support Centre at 1-800-828-6860 English or 1 800 503 3222 (French) for programming assistance to obtain the 138 km/h (86 mph) speed calibration. To ensure that you are provided with the correct calibration, you must refer to field action bulletin 07201 and ask the Customer Support Centre for the 138 km/h (86 mph) speed calibration. Also, provide the Customer Support Centre with the vehicle identification number (VIN).

Reprogram the body control module (BCM). Use the Tech 2 Pass-Thru Method for reprogramming the BCM. Follow the instructions below.

Notice: Before reprogramming, please check the battery condition to prevent a reprogramming error of any of the modules due to battery discharge. Battery voltage must be between 12.5 and 13 volts during reprogramming. If the vehicle battery is not fully charged, use jumper cables from an additional battery. Be sure to turn off or disable any system that may put a load on the battery, such as automatic headlamps, daytime running lights, interior lights, heating, ventilation, and air conditioning (HVAC) system, radio, engine cooling fan, etc. A programming failure or control module damage may occur if the battery voltage guidelines are not observed. Only use approved Midtronics charger or jumper packs, etc. to maintain proper battery voltage during programming.

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 Tech 2 software is up to date.

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. 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:

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 of a condition on your 2007 Chevrolet Silverado or GMC Sierra that could reduce the performance of the transmission. If your vehicle is driven at speeds of 143 km/h or higher, the vehicle's drive train may be subjected to vibration that overtime can cause a crack in the transmission housing and result in the loss of transmission fluid.

Your satisfaction with your 2007 Chevrolet Silverado or GMC Sierra is very important to us, so we are announcing a program to prevent this condition.

To prevent this condition from occurring, your GM dealer will reprogram the vehicle's body control module to attain highway speeds of up to 138 km/h. This service will be performed for you at no charge until August 31, 2008 .

To limit any possible inconvenience, we recommend that you contact your General Motors dealer as soon as possible to schedule an appointment for this repair. By scheduling an appointment, your dealer can ensure that the necessary parts will be available on your scheduled appointment date.

You may be contacted by a dealer other than the dealer who sold or is currently servicing your vehicle. Please be advised that you may take your vehicle to the General Motors dealership of your choice to have the recall service work completed.

This letter identifies your vehicle. Presentation of this letter to your dealer will assist their Service personnel in completing the necessary correction to your vehicle in the shortest possible time.

We are sorry to cause you this inconvenience; however, we have taken this action in the interest of your continued satisfaction with our products.

Customer Support Department

General Motors of Canada Limited

07201