18-021-26

Flash: Powertrain Control Module (PCM) Updates Customers **must** experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle **must** SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs):
• P0300-00 - Multiple Cylinder Misfire - in Active or Stored status set during cold start catalyst heating.
• P0301-00 - Cylinder 1 Misfire - in Active or Stored status set during cold start catalyst heating.
• P0302-00 - Cylinder 2 Misfire - in Active or Stored status set during cold start catalyst heating.
• P0303-00 - Cylinder 3 Misfire - in Active or Stored status set during cold start catalyst heating.
• P0304-00 - Cylinder 4 Misfire - in Active or Stored status set during cold start catalyst heating.
• P0305-00 - Cylinder 5 Misfire - in Active or Stored status set during cold start catalyst heating.
• P0306-00 - Cylinder 6 Misfire - in Active or Stored status set during cold start catalyst heating.**
• P2097 - Downstream Fuel Trim System 1 Rich.
• P2099 - Downstream Fuel Trim System 2 Rich. **Customers may comment on one or more of the following:
• Vehicle has a rough idle.
• Engine has a miss.
• Noisy valvetrain.**
• Lack power/responsiveness for the first couple of minutes or about 90 seconds after a cold start and later performs as expected. This bulletin involves reprogramming the PCM with the latest available software.