Interpretation ID: aiam4906
Inc. Morse Controls Division 21 Clinton Street Hudson
OH 44236-2899;
"Dear Mr. Reed: This responds to your letter concerning Federal Moto Vehicle Safety Standard No. 102, Transmission shift lever sequence, starter interlock, and transmission braking effect, as it relates to electronic transmission shift controls that operate automatic transmissions used in heavy duty trucks and RV's and on solenoid operated powershift transmissions used in various on and off highway vehicles. You asked whether 'the intent of section S3.l.3 of the standard is to render the engine starter inoperative when the transmission is in a forward or reverse drive gear or when the shift lever . . . is in such a gear.' As discussed below, Standard No. 102 expressly provides that the engine starter shall be inoperative when the transmission shift lever is in a forward or reverse drive position. By way of background information, the National Highway Traffic Safety Administration (NHTSA) does not provide approvals of motor vehicles or motor vehicle equipment. Under the National Traffic and Motor Vehicle Safety Act, it is the responsibility of the manufacturer to ensure that its vehicles and equipment meet applicable standards. The following provides our opinion based on the facts provided in your letter. Section S3.l.3 of Standard No. 102 reads as follows: S3.1.3 Starter interlock. The engine starter shall be inoperative when the transmission shift lever is in a forward or reverse drive position. The standard thus expressly provides that the engine starter shall be inoperative when the transmission shift lever is in a forward or reverse drive position. You state in your letter that '(t)he interests of public safety will be best served by requiring that the engine starter be inoperative when the transmission itself, not the transmission shift lever, is in a forward or reverse drive gear.' According to your letter, with the introduction of electronic shift systems and fully electronic transmissions, the connection between the shift lever and the transmission is rarely performed by direct mechanical means, and there is a possibility that the shift lever position may not match the gear currently engaged by the transmission in situations where the transmission control circuitry overrides the shift lever selection in the interest of safety, transmission protection or other criteria related to specific applications. You state that any attempt to artificially match the electronic shift lever's position to the gear currently enaged by the transmission in such override situations involves added cost and complexity, as well as safety and reliability concerns. You also argue that requiring the shift lever to be moved to neutral when the transmission itself is already in neutral due to some override condition imposes unnecessary safety hazards in some applications. You should be aware that sections S3.l.4.l and S3.l.4.2 of Standard No. 102 require identification of shift lever positions, including the positions in relation to each other and the position selected, to be displayed in view of the driver. A design where the shift lever position displayed to the driver did not match the gear currently engaged by the transmission would not comply with this requirement, since it would not show the position selected. We believe that such a design raises obvious safety concerns, regardless of the technology used for the transmission and shift system, since it would mislead the driver concerning the gear position selected. I note that the vehicles your letter asks about include, among others, 'various on and off highway vehicles,' and that the term 'off highway vehicles' could include certain vehicles which are not considered 'motor vehicles.' Standard No. l02, as well as NHTSA's other safety standards, apply only to motor vehicles. I hope this information is helpful to you. If you have any further questions or need any additional information about this topic, please feel free to contact Dorothy Nakama of my staff at this address or at (202) 366-2992. Sincerely, Paul Jackson Rice Chief Counsel";