DRIVEABILITY IMPROVEMENTS (REPLACE PROM)

SUBJECT: DRIVEABILITY IMPROVEMENTS

MODEL and YEAR: 1991-93 CAPRICE WITH 5.0L AND 5.7L ENGINES

ENGINE APPLICATIONS: 5.0L and 5.7L (RPOs L03 and L05)

ENGINE VIN (MODELS): E and 7

SUBJECT: Drivea bility Improvements (Detonation) - New Calibration

VEHICLE APPLICATIONS: 1991-93 Model Year B cars

THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 92-112A-6E, DATED NOV. 1992. THE 1993 MODEL YEAR HAS BEEN ADDED FOR VEHICLES FOR BROADCAST CODE BCDU, SCANNER I.D. 1391, P/N 16181390, 5.0L B CARS. ALL COPIES OF 92-112A-6E SHOULD BE DISCARDED.

CONDITION:

--------- Some owners of 1991-1993 model year B cars with either the L03 (VIN E 5.0L V8) or L05 (VIN 7 5.7L V8) engine may comment on low speed driveability or engine detonation (spark knock).

CORRECTION:

---------- The calibrations have been refined to address these concerns. If, after completing normal diagnostics, the condition remains, replace the PROM with the appropriate one from the table below:

NOTE: For L03 B-car only, make certain the vehicle has been updated with the previously attempted service fixes as follows.

DESCRIPTION PART NUMBER ----------- ----------- EGR Valve 17090156 (Stamped on Valve) 17112373 (GMSPO Kit)

PCV Valve 25098542

ESC Module 16175099 Broadcast Code (BARC)

Broadcast Scanner Part Model Code I.D. Number Year Body Application ---------------------------------------------------------------- AYMJ 5941 16165912 1991 B 5.0L L03 Wagon - California Emissions

AYMK 5951 16165913 1991 B 5.0L L03 Sedan - California Emissions

AYKA 5301 16165380 1991 B 5.0L L03 Police Sedan - Federal Emissions

AYKB 5311 16165384 1991 B 5.0L L03 Public Service Wagon - Federals Emissions

BATJ 5901 16175898 1991-92 B 5.7L L05 Sedan and Wagon - Nationwide Emissions

BCDU 1391 16181390 1991-93 B 5.0L L03 Sedan and Wagon - Federal Emissions Parts are currently available from GMSPO.

SERVICE INFORMATION:

Labor Operation: T0500

Labor Time: B Car 0.5 hour

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.