Technical Service Bulletins, or TSBs, are recommended procedures for repairing vehicles. Not to be confused with recalls, a TSB is issued by a vehicle manufacturer when there are several occurrences of an unanticipated problem.
TSBs can range from vehicle-specific to covering entire product lines and break down the specified repair into a step-by-step process.
While sometimes written by engineers employed by OEMs, the majority are authored by the first automotive technician to come up with a repair procedure.
Because certain problems may have more than one cause and there is sometimes more than one way to fix a problem, it's somewhat common for there to be more than one TSB for the same problem.
Some benefits of an automotive TSB are that by widely circulating among dealership service departments and mechanics an engineering-level description and solution for a problem common to type, year, make or model of car, a well-managed TSB process can save technicians troubleshooting time; provide organized, itemized repair procedures; and standardize the repair process.