CHUGGLE AT LOW SPEEDS & D.I.C. INACCURATE MILEAGE-NEW MEM-CAL

SUBJECT: CHUGGGLE AT LOW SPEED (45-60) KPH/INACCURATE DRIVER INFO SYSTEM MILEAGE - NEW MEM-CAL)

VEHICLES AFFECTED: 89-90 'N' W/2.3L (VIN D) AND 3T40 A/T

If concerns about chuggle between speeds of 45-60 KPH are received and thorough diagnosis of the engine control system does not resolve the concern, you may need to install a revised Mem-Cal.

The other condition of inaccurate fuel economy, on vehicles equipped with the Driver Information System (DIS) option may also be corrected by the installation of one of these Mem-Cals.

PARTS INFORMATION:

Part Scan Broadcast Model Transaxle Emissions Number I.D. Code ----- --------- --------- -------- ---- --------- 1989 Auto Federal 16156388 6353 AWNB 1990 Auto Federal 16156310 5993 AWLU

These Mem-Cals raised the TCC engagement speed to 60 kph and reduce the throttle position, crowd release of TCC. However, the vehicle fuel economy may be affected. Be sure to advise the owner of this.

NOTICE: This Mem-Cal is intended to be used on a as needed basis. The part number will be in CANSPO but as a field fix only. This will not be published in the CANSPO catalogue.

Parts are currently available from CANSPO.

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.