Interpretation ID: nht71-1.23

DATE: 12/20/71

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: Mechanism Division

TITLE: FMVSS INTERPRETATION

TEXT: Your letter of November 4, 1971, concerning the compliance of two dual rear door locking systems with Standard 206, has been forwarded to this office for reply.

Both systems consist of

. . . a primary locking system which when engaged renders the outside rear door handle and the inside rear door handle inoperative and a special locking device accessible from the door shut face, which when engaged renders the inside door handle imperative but does not affect the outside door handle.

The systems differ is that engagement of the special locking device in the first system prevents the engagement of the primary locking system, while engagement of the special device in the second system does not have this effect.

As stated in the preamble to the April 27, 1968 amendment (33 F.R. 6465) to the standard, S4.1.3 does not preclude the installation of a special locking mechanism in addition to the required locking mechanism. However, the required locking mechanism must be engageable or disengageable regardless of whether any additional locking mechanism is engaged or disengaged. If the special locking mechanism does not interfere with the operation of the required locking mechanism, it will not constitute a failure to comply with the standard.

Under these criteria, the first dual system would not comply with the standard since engagement of the special locking mechanism would interfere with the operation of the primary locking mechanism.

The second dual system would comply if engagement of the special locking mechanism would prevent neither the engagement nor the disengagement of the primary locking mechanism.

Please write if I can be of any further assistance.