18-052-15 REV A

Flash: 5.7L Powertrain Diagnostic And System Enhancements This bulletin involves reprogramming the Powertrain Control Module (PCM) with the latest available software. A small number of customers may experience one or more of the following symptoms or a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find one or more of the following Diagnostic Trouble Codes (DTCs) set in the Powertrain Control Module (PCM): ? U0140 - Lost Communication With Body Control Module (LD and LX). ? U0140 - Lost Communication With Body Control Module (TIPM) stored in the Engine Control Module (ECM) memory (LC vehicles). ? P1621 - O2 Sensor Reference Voltage Circuit Low. ? P1622 - O2 Sensor Reference Voltage Circuit High. ? P0606 - Internal Control Processor. ? P219A - Air-Fuel Ratio Cylinder Imbalance Bank 1. ? P0300 - Multiple Cylinder Misfire (applies only to vehicles using a block heater in ambient temperatures greater than -20°F (-29°C). ? Technicians may find that the original vehicle Frequency Operated Button Integrated Key (FOBIK) does not function properly following replacement of the Wireless Ignition Node (WIN/WCM). The Secret Key information stored in the PCM may be corrupt. This update will restore the PCM?s ability to store/transfer valid Secret Key information (LC vehicles). ? Accuracy improvements for the Automatic Oil Change Indicator (AOCI) system.