TSB 2025 Ram 1500 Powertrain Control Module (PCM) Update — 18-079-26

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Technical Service Bulletin · TSB 18-079-26

This is a Technical Service Bulletin, not a recall. A TSB tells dealers how to diagnose and repair a specific symptom when a truck comes in with it. It doesn't mean every truck listed has the problem, and it doesn't by itself make the repair free -- coverage depends on your warranty and the dealer's diagnosis.

Published: Oct 7, 2026
Applies to: Ram 1500 (2025 model year)

Summary (official text)​

Flash: Powertrain Control Module (PCM) Update Customers may experience a Malfunction Indicator Lamp (MIL) illumination, and the vehicle may exhibit SYMPTOM: or 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. Customers may also comment on one or more of the following: ● Vehicle has a rough idle. ● Engine has a miss. ● Noisy valvetrain. This bulletin involves inspecting the PCM software level and, if necessary, reprogramming the PCM with the latest available software.

Sources​

• 18-079-26 (PDF, NHTSA document 11038499) — Oct 7, 2026
• 18-079-26 (PDF, NHTSA document 11038536) — Oct 7, 2026

Details from NHTSA as of Oct 17, 2026. If NHTSA or Ram revises this notice, this post is updated and significant changes are noted in a reply. The linked documents are the authority, and a dealer can confirm whether it applies to your VIN.

Have you experienced this issue with your truck? Let us know your model year and engine, plus any diagnosis or repair details.