COLD/WARM ENG.DRIVEABILITY CHANGES - NEW MEMCAL. Pontiac Optima (Canada) 1991

For 1990-2009 cars

# COLD/WARM ENG.DRIVEABILITY CHANGES - NEW MEMCAL

#### Subject: COLD/WARM ENGINE DRIVEABILITY CHANGES (INSTALL NEW MEMCAL)

#### Models Affected: 1990-91 LE MANS WITH 1.6L

A production running change was made to release a new ECM (Electronic Control Module) to address Cold/Warm Engine Driveability Conditions. If a customer comments about these conditions and the vehicle was built prior to the following VIN breakpoints the conditions may be corrected with a new service calibration Memcal available from GMSPO according to the chart below:

Installation of the new Memcal should be according to the service procedure in the 1991 LeMans Service Manual.

OLD NEW TRANS OLD ECM B.C. NEW ECM B.C. NEW MEMCAL SCANNER VIN EMIS. P/N CODE P/N CODE P/N ID B/P ----- ------- ----- ------- ---- ---------- -------- ---- M/T 16139549 ASFL 16159509 AXCC 16160757 9509 MB319634 FEDERAL

A/T 16139539 ASFK 16159529 AXCF 16160767 9529 MB317305 FEDERAL

A/T 16139559 ASFM 16160739 AXJL 16160882 0739 MB322908 CALIFORNIA

M/T 16134189 ARAW 16159519 AXCD 16160762 9519 MB322907 CALIFORNIA

Parts are expected to be available on May 27, 1991. Until then normal part orders will not be accepted by GMSPO. only verifiable emergency VIP orders will be accepted. SPO will make every effort to obtain parts. All parts will be placed on 400 control to waive VIP surcharges. However, the part will be shipped premium transportation at dealer's expense. All other order types will be cancelled as incorrectly ordered while the 400 control is in place.

Labor Operation Number: J 6364

Labor Time : 0.7 Hours

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.