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 Dagnostic Trouble Codes (DTCs).
? DTC: U0140 - Lost Communication With Body Control Module (TIPM) stored in the
Engine Control Module (ECM) memory (applies only to LC vehicles).
? DTC: P1621 - O2 Sensor Reference Voltage Circuit Low
? DTC: P1622 - O2 Sensor Reference Voltage Circuit High
? DTC: P0606 - Internal Control Processor
? DTC: 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 (applies only to LC vehicles).
? Accuracy improvements for the Automatic Oil Change Indicator (AOCI) system.
