Interpretation ID: 24183

Mr. James F. Flint
Grove, Jaskiewicz & Cobert
Suite 400
1730 M Street, NW
Washington, DC 20036-4517

Dear Mr. Flint:

This responds to your letter of March 8, 2002, in which you ask whether the tire pressure monitoring system (TPMS) manufactured by your client, Col-Ven SA of Argentina, for large commercial motor vehicles will be subject to the pending rulemaking on TPMSs. As discussed below, the agency did not propose to require TPMSs on medium and heavy vehicles in its proposed rule. However, we cannot give you a definitive answer at this time as to what the final rule will require.

In your letter, you state that Col-Ven SA manufacturers a TPMS intended for commercial motor vehicles with a gross vehicle weight rating over 26,000 pounds, including large trucks, truck tractors, tractor/trailer combinations, passenger buses, and large recreational vehicles.

In your letter you also refer to an April 29, 1998, National Highway Traffic Safety Administration (NHTSA) interpretation letter (see enclosure) regarding another TPMS manufactured for heavy vehicles. In that letter, NHTSA stated that there was no Federal Motor Vehicle Safety Standard (FMVSS) applicable to TPMSs. However, the agency cautioned that the installation of any such system, either as original equipment or as after-market equipment, is prohibited if it makes "inoperative any device or element of design that was originally installed on or in the vehicle pursuant to any FMVSS." The agency indicated that such a system might impact air brake systems (covered by FMVSS No. 121) or brake hoses (FMVSS No. 106).

You ask whether this interpretation letter has been superseded or altered by the passage of the Transportation Recall Enhancement, Accountability and Documentation (TREAD) Act, ⁽¹⁾ and whether TPMSs manufactured for large commercial motor vehicles will be subject to the rulemaking on TPMSs required by Section 13 of the TREAD Act.

Section 13 of the TREAD Act mandates the completion of "a rulemaking for a regulation to require a warning system in new motor vehicles to indicate to the operator when a tire is significantly under inflated." On July 26, 2001, NHTSA issued a notice of proposed rulemaking (NPRM) proposing a new FMVSS (No. 138) with requirements for TPMSs. ⁽²⁾ The agency proposed to require TPMSs on light vehicles, i.e., passenger cars, multipurpose passenger vehicles, trucks, and buses with a GVWR of 10,000 pounds or less. The agency did not propose to require TPMSs on medium (10,001 - 26,000 pounds GVWR) and heavy (greater than 26,001 pounds GVWR) vehicles.

NHTSA also noted in the NPRM that the Federal Motor Carrier Safety Administration (FMCSA) is addressing tire maintenance issues for heavy vehicles. FMCSA plans to conduct a comprehensive study, including possible fleet evaluations of different TPMSs, of all the issues related to improvement of heavy vehicle tire maintenance. The agency plans on working with FMCSA in examining the desirability of proposing a TPMS standard for heavy vehicles.

The agency received one comment requesting that we initiate a separate rulemaking to consider TPMS requirements for medium and heavy vehicles. We will address that comment in the final rule. In the meantime, we can tell you that the April 28, 1998 interpretation letter discussed above is valid with respect to medium and heavy vehicles.

I hope you find this information helpful. If you have any further questions on TPMSs, please feel free to contact Dion Casey of my staff at (202) 366-2992.

Sincerely,

Jacqueline Glassman
Chief Counsel

Enclosure
ref:138
d.4/22/02

² 66 FR 38982.