Exhaust Gas Recirculation Valve Misbuilds

General Motors has decided to conduct a Voluntary Emission Campaign involving certain 1999 Chevrolet Silverado and GMC Sierra model trucks, equipped with 4.8 L (RPO LR4) and 5.3 L (RPO LM7) engines. These vehicles may have been built with the wrong Linear Exhaust Gas Recirculation (LEGR) valve. This could lead to a condition in which the valve would limit the required air flow rate and may fail a diagnostic test. If the LEGR valve fails, it can result in setting a Malfunction Indicator Lamp (MIL). If the MIL is ignored, the vehicle may fail to meet applicable emissions requirements.

To correct this condition, dealers are to inspect the EGR valve for a correct bar code number or a stamped production part number code and, if necessary, replace the valve with a new EGR valve.

Also, in order to correct a potential EGR valve rapid cycling condition in ambient temperatures between 1° and 4°C (34° and 39°F) that could set an EGR Malfunction Indicator Lamp (MIL), dealers are to take this opportunity to reflash the PCM in the GMT800 trucks equipped with the 5.3 L (RPO LM7) engine, only.

Involved are certain 1999 Chevrolet Silverado and GMC Sierra model trucks, equipped with 4.8 L (RPO LR4) and 5.3 L (RPO LM7) engines and built within the following VIN breakpoints:

Important: Dealers should confirm vehicle eligibility through VISS (Vehicle Information Service System) prior to beginning campaign repairs. [Not all vehicles within the above breakpoints may be involved]

Involved vehicles have been identified by Vehicle Identification Number. Computer listings containing the complete Vehicle Identification Number, customer name and address data have been prepared, and are being furnished to involved dealers with the campaign bulletin. The customer name and address data furnished will enable dealers to follow-up with customers involved in this campaign. Any dealer not receiving a computer listing with the campaign bulletin has no involved vehicles currently assigned.

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

Parts required to complete this campaign are to be obtained from General Motors Service Parts Operations (GMSPO). Please refer to your "involved vehicles listing" prior to ordering parts. Normal orders should be placed on a DRO = Daily Replenishment Order. In an emergency situation, parts should be ordered on a CSO = Customer Special Order.

Important: It is estimated that only 16% of involved vehicles will require LEGR valve replacement. Please order parts accordingly.

The following table shows the GMT800 5.3 L engine calibration to use for reflash, available on 1999 Techline CD disc number 3 or later. Do not order these flash calibrations from GMSPO.

Customers will be notified of this campaign on their vehicles by General Motors (see copy of typical customer letter included with this bulletin - actual divisional letter may vary slightly).

In order to ensure full protection under the emission warranty, and the right to participate in future recalls, the customer notification letter recommends that customers have their vehicles serviced as soon as possible. It also advises that failure to do so could legally be determined to be lack of proper maintenance. The vehicle may fail a state or local emission inspection test if the recall work is not completed.

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

Dealers are to service all vehicles subject to this campaign 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. This could be done by mailing to such customers a copy of the customer letter accompanying this bulletin. Campaign 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 campaign enters your vehicle inventory, or is in your dealership for service in the future, please take the steps necessary to be sure the campaign correction has been made before selling or releasing the vehicle.

When a California emissions campaign is completed by a GM dealer, the dealer must provide the vehicle owner a "Proof Of Correction Certificate" which the owner may need to present to the California Department Of Motor Vehicles (DMV) when renewing their vehicle registration. Without this correction certificate, the owner may be unable to renew their vehicle registration.

Additional Certificates can be obtained, at no charge, from Dealer Support Materials by calling 1-888-414-6322, Monday-Friday, 8:00 am to 5:00 pm Eastern Standard Time. Ask for GM Item Number 1825 when ordering.

Figure 1

Each vehicle corrected in accordance with the instructions outlined in this Product Campaign Bulletin will require a "Campaign Identification Label". Each label provides a space to include the campaign number and the five (5) digit dealer code of the dealer performing the campaign service. This information may be inserted with a typewriter or a ball point pen.

Each "Campaign Identification Label" is to be located on the radiator core support in an area which will be visible when the vehicle is brought in by the customer for periodic servicing. When installing the Campaign Identification Label, be sure to pull the tab to allow the adhesion of the clear protective covering. Additional Campaign Identification Labels can be obtained from Dealer Support Materials by calling 1-888-414-6322 (Monday-Friday, 8:00 am to 5:00 pm Eastern Standard Time). Ask for Item Number S-1015 when ordering.

Apply the "Campaign Identification Label" only on a clean, dry surface.

Submit a Product Campaign Claim with the information indicated below. Refer to the General Motors Corporation Claims Processing Manual for details on Product Campaign Claim Submission.

Dear <Division(s)> Customer:

This notice is sent to inform you that General Motors is conducting a customer satisfaction recall campaign, involving an emission component, that includes your vehicle.

General Motors has decided to conduct a Voluntary Emission Campaign involving certain 1999 Chevrolet Silverado and GMC Sierra model trucks, equipped with 4.8 L and 5.3 L engines. These vehicles may have been built with the wrong Linear Exhaust Gas Recirculation (LEGR) valve. This could lead to a condition in which the valve would limit the required air flow rate and may fail a diagnostic test. If the LEGR valve fails, it can result in setting a Malfunction Indicator Lamp (MIL). If the MIL is ignored, the vehicle may fail to meet applicable emissions requirements.

To correct this condition, your dealer will inspect the EGR valve and, if necessary, replace it with the correct EGR valve. Also, for owners of trucks equipped with a 5.3 L engine, dealers will reflash the calibration software in the PCM. This service will be performed for you at no charge .

Please contact your dealer as soon as possible to arrange a service date and to assure parts availability. Instructions for making this correction have been sent to your dealer. Please ask your dealer if you wish to know how much time will be needed to schedule, process and repair your vehicle.

Should your dealer be unable to schedule a service date within a reasonable time, you should contact the appropriate Customer Assistance Center at the number listed below:

The enclosed customer reply card identifies your vehicle. Presentation of this card 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 postage paid reply card and returning it to us.

In order to ensure your full protection under the emission warranty made applicable to your vehicle by State or Federal Law, and your right to participate in future recalls, it is recommended that you have your vehicle serviced as soon as possible. Failure to do so could legally be determined to be lack of proper maintenance of your vehicle. Also, your vehicle may fail a state or local emission inspection if this recall is not accomplished.

The California Air Resources Board (CARB) requires vehicle emission recall campaigns be completed prior to California registration renewal. Uncorrected emission recall campaigns will result in the inability to renew your California vehicle registration.

At the time of emission campaign completion, your California dealer will issue a "Proof Of Correction Certificate". Keep this certificate and, if required, present it to the Department of Motor Vehicles when renewing your California registration as proof of campaign completion.

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

<Division(s)>

General Motors Corporation

Enclosure