Technical Service Bulletin (TSB)

A technical service bulletin, or TSB, is an internal repair instruction from an automaker to its dealers. It typically describes a symptom owners are reporting (a noise, a warning light, a leak, a software glitch), identifies the affected models and years, and tells technicians what part or procedure fixes it. TSBs are common; a single model year can have dozens.

A TSB is not a recall. A safety recall is a formal process in which the manufacturer notifies owners and fixes the defect at no charge. A TSB usually applies only if you bring the car in with the problem, and the repair may be free only while the car is under warranty. That difference is why TSBs matter in lawsuits.

TSBs are also public. Under 49 U.S.C. 30166(f), a vehicle manufacturer must give the Department of Transportation a copy of each communication it sends to dealers or owners about a defect, and the government must make those copies available on a public website. You can look up TSBs for your vehicle by entering its make, model, and year or its VIN on NHTSA's recalls site.

In defect class actions, TSBs are often key evidence: a bulletin issued years before a recall can show the manufacturer knew about a problem while it kept selling cars and charging owners for repairs outside warranty. Owners use them in lemon law cases, too, to show a defect is real and recurring. If you paid for a repair that matches a TSB, keep the invoice. See our lemon law explainer, recall vs. class action, and vehicle cases like the Volkswagen oil consumption lawsuit.