CHUGGLE AT 35-45 MPH WITH TCC ENGAGED-REVISED PROM RELEASED

Subject: CHUGGLE AT 35-45 MPH WITH TORQUE CONVERTER CLUTCH ENGAGED (REVISED PROM)

Models/Years: 1987 BONNEVILLE MODELS WITH 3.8L ENGINE

Some owners of 1987 Bonneville models equipped with 3.8L (code B and 3) engine and standard axle ratio may experience a condition of chuggle at 35-45 MPH with the torque converter clutch engaged. If the condition cannot be repaired using currently published service and diagnostic procedures, it may be necessary to install a revised calibration prom.

The proms are currently available through GMSPO under the following numbers.

PROM PROM PROM TRANSAXLE AXLE SERVICE SCANNER BROADCAST YEAR SERIES RATIO PART NO. I.D. NO. CODE ---- --------- -------------- -------- -------- ------- 1987 Bonneville FP3/2.73 16158373 8414 AWXA (Fed. & Calif.)

WARRANTY INFORMATION: Use applicable labor operation and time.

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.