CAMPAIGN:MASS AIR FLOW SENSOR FAILURE-INSPECT/REPLACE

MODELS AFFECTED: 1987 CENTURYS, LESABRES, SOMERSETS AND SKYLARKS EQUIPPED WITH 3.OL AND 3.8L PORT FUEL INJECTED ENGINE

General Motors has determined that certain 1987 Buicks equipped with 3.OL or 3.8L fuel injection engines were assembled with a MAF (mass air flow) sensor that may contain cracked sensor foils.

It is possible that this MAF sensor could cause the vehicle's Service Engine Soon Light to turn "on" (Trouble Code 34), and emission system to operate in the backup mode. Also, the engine may intermittently not stay running at the closed throttle position, with no SES light indication.

DEALER ACTION

To correct this condition on vehicles involved, dealers are to inspect, and if required, replace the MAF sensor as instructed in the Technical Procedure of this bulletin.

VEHICLES INVOLVED

Certain 1987 Centurys, LeSabres, Somersets and Skylarks equipped with 3.OL (VIN Code L) or 3.8L (VIN Code 3) fuel injected engines within the following vehicle breakpoints:

SERIES ENGINE PLANT FROM THRU & INCLUDING ------ ------ ----- ---- ---------------- Centurys 3.8L Doraville HD400001 HD405271 (LG3) LeSabres 3.8L Flint HH400001 HH409294 (LG3) Somersets 3.OL Lansing HM000036 HM001790 & Skylarks (LN7)

DEALER CAMPAIGN RESPONSIBILITY

Dealers are to service all vehicles involved in this campaign, at no charge to owners, regardless of mileage, age of vehicle, or ownership. Whenever a vehicle subject to this campaign is taken into your new or used car inventory, dealers are to take the steps necessary to be sure the campaign correction has been made before reselling the vehicle.

In addition, dealers are to perform the campaign on all affected vehicles as they are brought in for any kind of service.

DEALER MATERIAL

If your dealership has vehicles involved in this campaign, you will receive the following items:

o Listing of all vehicles involved in this campaign shipped to your dealership. o One (1) Campaign Identification Label per vehicle involved. o One (1) MAF Sensor for each vehicle.

Involved vehicles have been identified by Vehicle Identification Number computer listings. Computer listings contain the complete vehicle identification number, owner rame and address data, and are furnished to the involved dealers with the campaign bulletin. Owner name and address data will enable dealers to follow-up with owners involved in this campaign.

These Computer listings may contain owner 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.

OWNER NOTIFICATION

Owners of vehicles involved in this campaign will be notified by Buick Motor Division (see copy of owner letter included with this bulletin).

PARTS INFORMATION

The MAF (mass air flow) sensors will be furnished "no charge" for each vehicle by Buick. There are 2 MAF sensors involved and their usage is identified by the following part numbers:

Sensor Part # Model Usage ------------- ----------- 25007835 Century - 3.8L Engine 25007834 Somerset & Skylark - 3.OL Engine 25007834 LeSabre - 3.8L Engine

The sensors will be shipped via UPS and identified for Campaign 87-C-2. Replaced or unused sensors are to be returned as instructed in Parts Disposition section of this bulletin.

TECHNICAL PROCEDURE

1. Raise vehicle hood, cover fenders, and inspect MAF sensor. Refer to illustration.

a. If the sensor has a white paint dot on it's side as shown, no further action is required except to apply a Campaign Identification Label.

b. If the sensor does not have a white dot, replace it with correct part furnished by Buick. Refer to Parts Information Section for correct part number usage.

Refer to Page 6E3-Cl-8 in the 1986 Buick Chassis Service Manual for sensor replacement.

2. If the MAF sensor was replaced, start vehicle engine and note if there is a SES light "on" which would indicate incorrect wiring connection at the sensor. Correct as required and clear stored code.

3. Install a Campaign Identification Label.

Each label provides a space to include the campaign number, the five (5) digit dealer code of the dealer performing the campaign service, and the date vehicle was campaigned. This information may be inserted with a typewriter or ballpoint pen. When installing label, clean the surface of the radiator support tie bar. When installing label, clean the surface and apply the campaign label where it is readily visible.

4. Return sensor as follows on next page.

DISPOSITION OF MAF SENSOR (NEW OR REPLACED)

Replaced sensors must have a claim tag attached showing the repair order and the VIN of the vehicle from which it was removed. Return the replaced sensor in the carton the new one was received in, apply furnished merchandise return label over old mailing label and place in the mail. Postage will be paid by General Motors.

If the new sensor furnished was not required, it is also to be returned using furnished shipping label.

WARRANTY INFORMATION

LIST THE ONE APPLICABLE LABOR OPERATION

PART FAILED PARTS FAILURE LABOR LABOR OTHER DEALER OPER. COUNT PART NO. ALLOW. CODE OP NO HOURS HOURS MTL TWG

Inspect Only - - - 96 V3610 .2 *.1 - Inspect & Replace MAF Sensor +++ 1 ++ - 96 V3611 .2 *.1 $41.16

* .1 hour for administration. ++ List part number of replace MAF sensor. +++ $41.16 is for 30% of dealer price of furnished MAF sensor.

Dear Buick Owner:

General Motors has determined that certain 1987 Centurys, LeSabre, Somersets, and Skylarks equipped with 3.OL or 3.8L port fuel injected engines may be equipped with a mass air flow sensor containing cracked sensor foils. The mass air flow sensor which is part of the engine's fuel and emission system may fail, resulting in poor driveability and may affect exhaust emissions.

To correct this condition, your dealer will inspect and replace, if required, the mass air flow sensor on your vehicle. This service will be performed at no charge to you.

Instructions for this service have been sent to your Buick dealer. The labor time necessary to perform this modification is approximately 10 minutes. Please allow time for the dealer to process your vehicle. Please contact your dealer to arrange a mutually satisfactory service date.

The enclosed Owner Reply Card identifies your vehicle. Presentation of this card to your dealer will assist him in making the repair to your vehicle in the shortest possible time. If you have sold or traded your vehicle bearing the identification number on this card, please let us know by completing the postage paid Owner Identification Reply Card and returning it to us so that we may update our records. Should your dealer not schedule a service date within a reasonable time, you should contact the Buick Customer Assistance Department, Flint Home Office by calling 800-521-7300.

We are sorry to cause you this inconvenience; however, we have taken this action to assure that your vehicle meets applicable government emission requirements, and in the interest of your continued satisfaction with our products. We urge your prompt cooperation in this matter.

Buick Motor Division GENERAL MOTORS CORPORATION

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.