For 1990-2009 cars

# CAMPAIGN:MASS AIR FLOW SENSOR FAILURE-INSPECT/REPLACE

1987 Buick Century, Lesabre, Somerset, Skylark; Oldsmobile Ninety-Eight, Delta 88, Cutlass Ciera, Calais; Pontiac Grand Am and Bonneville models equipped with 3.0L and 3.8L Port Fuel Injected engines.

#### CONDITION:

--------- General Motors of Canada has determined that certain Buick, Oldsmobile and Pontiac models equipped with 3.0L 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 Service Procedure of this bulletin.

#### VEHICLES INVOLVED:

Certain 1987 Century, LeSabre, Somerset, Skylark, Ninety-Eight, Delta 88, Ciera, Calais, Grand Am and Bonneville models equipped with 3.0L (VIN Code L) or 3.8L (VIN Code 3) fuel injected engines within the following vehicle breakpoints:

THRU & BUICK ENGINE PLANT FROM INCLUDING ----- ------ ----- ---- ---------- Centurys 3.8L Doraville(D) HD400001 HD405271 (LG3)

LeSabres 3.8L Flint (H) HH400001 HH409294 (LG3)

Somersets 3.0L Lansing (M) HM000036 HM001790 (LN7) OLDMOBILE --------- Ninety-Eight 3.8L Orion (4) H4300001 H4304917 (LG3)

Delta 88 3.8L Wilow Run (W) HW300001 HW305897 (LG3)

Cutlass Ciera 3.8L Doraville (D) HD300796 HD302753 (LG3)

Calais 3.0L Lansing (M) HM200001 HM201870 (LN7) PONTIAC ------- Grand AM 3.0L Lansing (C) HC700001 HC703715 (LN7)

Bonneville 3.8L Willow Run (W) HW200001 HW200363 (LG3)

All affected vehicles have been identified by the VIN listing provided to involved Dealers with this bulletin. Any Dealer not receiving a listing was not shipped any of the affected vehicles.

#### DEALER CAMPAIGN RESPONSIBILITY:

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

Whenever a vehicle subject to this campaign is taken into your new or used vehicle inventory, or it is in your Dealership for service in the future, you should take the steps necessary to be sure the campaign correction has been made before reselling or releasing the vehicle.

Owners of vehicles recently sold f rom your new vehicle inventory are to be contacted by the Dealer, and arrangements made to make the required modification according to instructions contained in this bulletin.

#### CAMPAIGN PROCEDURE:

Refer to Section 4 of the Service Policies and Procedures Manual for the detailed procedure on handling Product Campaigns. Dealers are requested to complete the campaign on all transfers as soon as possible.

#### OWNER NOTIFICATION:

All owners of record at the time of campaign release are shown on the attached computer listing and have been notified by first class mail from General Motors. The listings provided are for campaign activity only and should not be used for any other purpose.

#### PARTS INFORMATION:

Mass Air Flow sensors, if required, should be ordered through regular channels as follows:

Ciera, Century 3.8L (LG3) 25007872

LeSabre, Ninety-Eight, Delta 88 3.8L (LG3) 25007834 Calais, Somerset 3.OL (LN7) Grand Am, Bonneville

#### PARTS AND LABOUR CLAIM INFORMATION:

Credit for the campaign work performed will be paid upon receipt of a properly completed campaign claim card or RAPID terminal transmission in accordance with the following:

Repair Code Operation Time Allowance ----------- --------- -------------- 1A Inspect Only .3

2A Inspect & replace MAF Sensor .3

Time allowance includes 0.1 hour for Dealer administrative detail associated with this campaign. Parts credit will be based on Dealer net plus 30% to cover parts handling.

#### SERVICE PROCEDURE:

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

a. If the sensor has a white paint dot on its side as shown in Figure 1, no further action is required. Apply a Campaign Identification Label, Step 3 below.

b. If the sensor does not have a white dot, replace it with the correct part. (Refer to the Parts Information Section in this bulletin for correct part number usage).

OLDS Refer to Page 6E3-Cl-7 in the 1986 Firenza, Calais, Cutlass Ciera, Delta 88 and Ninety-Eight Chassis Service Manual for sensor replacement.

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

PONTIAC Refer to Page 6E3-Cl-8 in the 1986 Pontiac Grand Am Service Manual for sensor replacement.

2. If the MAF sensor was replaced, start engine and note if the "Service Engine Soon" light is on which would indicate an incorrect wiring connection at the sensor. Correct as required and clear stored code.

3. Install a Campaign Identification Label.

#### INSTALLATION OF CAMPAIGN IDENTIFICATION LABEL

Clean surface of radiator upper mounting panel and apply a Campaign Identification Label. Make sure the correct campaign number is inserted on the label. This will indicate that the campaign has been completed.

Dear General Motors Customer:

General Motors of Canada has determined that certain 1987 Buick Century, LeSabre, Somerset, Skylark; Oldsmobile Ninety-Eight, Delta 88, Ciera, Calais; Pontiac Grand Am and Bonneville models 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 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 GM Dealer. The labour 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.

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.

Further assistance, if required, may be obtained from the General Motors Zone Office nearest you. Your vehicle Owner's Manual provides the location and phone number of each respective Zone Office.

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

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.