TSB (Technical Service Bulletin)

What It Means

A Technical Service Bulletin (TSB) is a non-recall document issued by a manufacturer to its franchised dealers describing a known vehicle issue and the authorized diagnostic procedure or repair, typically along with the labor time and warranty claim code. TSBs address problems that the manufacturer considers too narrow in scope, too low in safety consequence, or too software-driven to meet the statutory "unreasonable risk to safety" threshold that would trigger a recall under 49 U.S.C. 30118. Examples of TSB topics include software calibration updates for transmission shift logic, revised torque specifications for suspension bolts, updated engine oil viscosity recommendations, fixes for infotainment freezes, and diagnostic procedures for unusual noises. TSBs are not safety recalls, so four important differences apply: the repair is not automatically free (it may or may not be covered under warranty depending on mileage and age), the manufacturer is not required to notify individual owners, completion rates are not tracked by NHTSA, and the "Do Not Drive" and rental-ban statutory protections do not apply. However, TSBs are filed with NHTSA under 49 CFR Part 579.5 within five business days of issuance, and the text and summary are published at nhtsa.gov, making them a valuable secondary data source. A pattern of related TSBs on a vehicle, for example, five separate TSBs addressing different symptoms of a transmission defect, is often an early signal that a formal recall may follow, especially if ODI is receiving related complaints. Famous cases where TSB patterns preceded major recalls include the 2014 GM ignition switch (multiple years of ignition-related TSBs predated the recall) and the 2015-2019 Hyundai/Kia engine-fire recall (engine-knock and bearing TSBs preceded the recall by several years).

TSB (Technical Service Bulletin) is one of the NHTSA or vehicle-safety concepts that recurs across RecallIndex. The definition above is the technical answer; below is how the concept connects to the NHTSA data that drives every vehicle page on the site.

In the RecallIndex Safety Score, this concept feeds one of the four factor weights — recall severity (40 percent), complaint frequency (30 percent), crash and fire reports (20 percent), or trend direction (10 percent). The methodology page on the site walks through every input in detail.

Frequently Asked Questions