Mr. Michael Love
Manager, Compliance
Porsche Cars North America, Inc.
100 West Liberty Street
P.O. Box 30911
Reno, Nevada 89520-3911

Dear Mr. Love:

This responds to your letter of December 19, 1995, requesting information concerning the readiness indicator requirement in S4.5.2 of Standard No. 208, Occupant Crash Protection. I apologize for the delay in responding.

S4.5.2 of Standard No. 208 states:

An occupant protection system that deploys in the event of a crash shall have a monitoring system with a readiness indicator. The indicator shall monitor its own readiness and shall be clearly visible from the driver's designated seating position.

You ask whether this requirement applies (1) to a voluntarily-installed inflatable restraint (not needed to comply with Standard No. 208), or (2) to an inflatable restraint installed to meet the requirements of another standard (such as Standard No. 214, Side Impact Protection). You state that Porsche believed that in both of these situations the manufacturer could install:

- no readiness indicator, or - a separate readiness indicator from that required by Standard No. 208, or - a readiness indicator combined with that required by Standard No. 208.

As explained below, for both types of inflatable restraints, we agree with the first two of these statements, but not necessarily with the third.

Voluntarily-Installed Inflatable Restraints

A crash-deployed occupant protection system installed in addition to required safety systems would not be required to

comply with the provisions of the safety standards. Thus, a readiness indicator would not be required. However, in the interest of safety, we would urge you to consider voluntarily providing a readiness indicator for the system.

As explained below, if you voluntarily provide a readiness indicator, and decide to combine it with the required readiness indicator, the information provided by the former must not confuse or obscure the information provided by the latter about the required air bag. The indicator must distinguish between the different air bag systems, such as by having dissimilar signals for the different systems.

While systems or components installed in addition to required safety systems are not required to comply with the standards, they must not make inoperative the compliance of the required systems (49 U.S.C. '30122). We urge you to make sure that by combining a voluntarily-installed readiness indicator with the required indicator, you do not prevent the latter from complying with Standard No. 208. If the messages of the two indicators were not distinguishable, a driver would not know if the illuminated telltale showed a problem with the occupant protection system installed to comply with Standard No. 208, or a problem with another system being monitored.

NHTSA addressed a related issue in a rulemaking that allowed manufacturers to install a manual cut-off device for a passenger-side air bag in certain situations (60 FR 27233; May 23, 1995). The agency stated there that the readiness indicator must monitor only the driver's air bag when the passenger-side air bag was deactivated. In other words, the indicator must not be affected by the deactivated state of the passenger-side air bag.

Systems Installed for a Standard Other than Standard 208

The requirement for a readiness indicator (S4.5.2) applies only to systems that are installed to comply with the requirements of Standard No. 208, and not to systems installed to comply with another standard. Air bag systems installed pursuant to Standard No. 208 are generally installed to meet the frontal protection requirements of that standard. While a readiness indicator is not required for systems installed for other purposes, we would urge the manufacturer to provide a means of monitoring the readiness of the system, consistent with the cautions above.

I hope this information has been helpful. If you have other questions or need some additional information, please contact Mary Versailles of my staff at this address or by phone at (202) 366-2992.


Samuel J. Dubbin Chief Counsel

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