Federal Motor Vehicle Safety Standard 138

Federal Motor Vehicle Safety Standard 138 (FMVSS 138) regulates motor vehicle tire-pressure monitoring system (TPMS) in the United States.

Background edit

The dangers of low tire pressure became more prominent following the Firestone and Ford tire controversy which led to the passing of the TREAD Act and the codification of FMVSS 138.

Like all other Federal Motor Vehicle Safety Standards, FMVSS 138 is administered by the United States Department of Transportation's National Highway Traffic Safety Administration.

The standard is to warn drivers of significant under-inflation of tires and the resulting safety problems of low tire pressure.[1]

This standard requires a tire-pressure monitoring system (TPMS) to be installed in all new passenger cars, multipurpose passenger vehicles, trucks, and buses that have a gross vehicle weight rating (GVWR) of 4,536 kg (10,000 lbs.) or less, except those vehicles with dual wheels on an axle. The final rule requires that the driver be given a warning when tire pressure is 25 percent or more below the vehicle manufacturer's recommended cold tire inflation pressure (placard pressure) for one to four tires.[2]

The standard became effective October 7, 2005 however voluntary compliance was allowed prior to this date.

Phase-in schedule edit

Primary phase-in schedule
Phase-in year Produced after August 31 Produced before September 1 % of manufacturer's vehicles certified to standard
1 2005[a] 2006 20
2 2006 2007 70
3 2007 100

See also edit

Notes edit

  1. ^ The initial effective date was October 5, 2005. Subsequent years were effective August 31.[3]


References edit

  1. ^ "49 CFR § 571.138 - Standard No. 138; Tire pressure monitoring systems". LII / Legal Information Institute.
  2. ^ "Tire pressure monitoring system" (PDF). nhtsa.gov.
  3. ^ "Federal Motor Vehicle Safety Standards; Tire Pressure Monitoring Systems". Federal Register. September 7, 2005. Retrieved August 20, 2023.