TSB 2026 Ram 1500 Trailer Tow Module (TTM) Update — 08-386-26

[RamRHOForum]

Technical Service Bulletin · TSB 08-386-26

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 20, 2026
Applies to: Ram 1500 (2026 model year)

Summary (official text)​

Flash: Trailer Tow Module (TTM) Update Customers may experience the following: SYMPTOM: ● 'Check Trailer Turn Lamp' message is displayed in the Instrument Panel Cluster (IPC) with no trailer connected. This bulletin involves inspecting and possibly reprogramming the TTM with the latest software.

Sources​

• 08-386-26 (PDF, NHTSA document 11038754) — Oct 20, 2026

Details from NHTSA as of Oct 30, 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.