Recall - MEM-CAL/PROM Update: Overview

CADILLAC
95-C-72

Issued: 08-01-96

SUBJECT:
95-C-72 - 4.9 LITER ENGINE PCM MEM-CAL/PROM REPLACEMENT

MODELS:
CERTAIN 1991-1995 CADILLAC VEHICLES EQUIPPED WITH 4.9 LITER ENGINE (RPO L26)

The Administrator of the U.S. Environmental Protection Agency (EPA) has determined that 1991-1995 model Cadillacs equipped with 4.9 liter engines may require modifications in order to comply with requirements of the Clean Air Act designed to protect the public health and welfare. GM has determined that the modifications required by EPA will help reduce emissions of carbon monoxide and hydrocarbons, which are regulated by EPA under the Clean Air Act.

In October 1991, GM implemented a change in its production of 1992 model Cadillacs equipped with 4.9 liter engines that introduced an enrichment calibration to the fueling strategy. This calibration was subsequently included in production of 1993-1995 model Cadillacs equipped with 4.9 liter engines and in service parts received by certain 1991-1992 model Cadillacs equipped with 4.9 liter engines. The United States alleges that this calibration has a detrimental effect on a vehicle's emission control system and that this calibration was not adequately reported to the EPA.

General Motors has agreed to modify the fueling strategy for these vehicles in a way that reduces the emission of air pollutants from the vehicles without compromising driveability. All vehicles that were built with the fueling strategy in question or which subsequently received the strategy through a service prom are being recalled to have the calibration inspected and, if necessary, revised via the installation of a new service prom.