571.102—Standard No. 102; Transmission shift position sequence, starter interlock, and transmission braking effect.

S1. Purpose and scope. This standard specifies the requirements for the transmission shift position sequence, a starter interlock, and for a braking effect of automatic transmissions, to reduce the likelihood of shifting errors, to prevent starter engagement by the driver when the transmission is in any drive position, and to provide supplemental braking at speeds below 40 kilometers per hour (25 miles per hour).
S2. Application. This standard applies to passenger cars, multi-purpose passenger vehicles, trucks, and buses.
S3. Requirements.
S3.1Automatic transmissions.
S3.1.1Location of transmission shift positions on passenger cars. A neutral position shall be located between forward drive and reverse drive positions.
S3.1.1.1Transmission shift levers. If a steering-column-mounted transmission shift lever is used, movement from neutral position to forward drive position shall be clockwise. If the transmission shift lever sequence includes a park position, it shall be located at the end, adjacent to the reverse drive position.
S3.1.2Transmission braking effect. In vehicles having more than one forward transmission gear ratio, one forward drive position shall provide a greater degree of engine braking than the highest speed transmission ratio at vehicle speeds below 40 kilometers per hour (25 miles per hour).
S3.1.3Starter interlock. Except as provided in S3.1.3.1 through S3.1.3.3, the engine starter shall be inoperative when the transmission shift position is in a forward or reverse drive position.
S3.1.3.1After the driver has activated the vehicle's propulsion system:
S3.1.3.2 Notwithstanding S3.1.3.1, the engine may stop and start at any time after the driver has activated the vehicle's propulsion system if the vehicle can meet the requirements specified in paragraphs (a) and (b):
S3.1.3.3If the transmission shift position is in Park, automatically stopping or restarting the engine shall not take the transmission out of Park.
S3.1.4Identification of shift positions and of shift position sequence.
S3.1.4.1Except as specified in S3.1.4.3, if the transmission shift position sequence includes a park position, identification of shift positions, including the positions in relation to each other and the position selected, shall be displayed in view of the driver whenever any of the following conditions exist:
S3.1.4.2Except as specified in S3.1.4.3, if the transmission shift position sequence does not include a park position, identification of shift positions, including the positions in relation to each other and the position selected, shall be displayed in view of the driver whenever the ignition is in a position in which the engine is capable of operation.
S3.1.4.3Such information need not be displayed when the ignition is in a position that is used only to start the vehicle.
S3.1.4.4All of the information required to be displayed by S3.1.4.1 or S3.1.4.2 shall be displayed in view of the driver in a single location. At the option of the manufacturer, redundant displays providing some or all of the information may be provided.
S3.2Manual transmissions. Identification of the shift lever pattern of manual transmissions, except three forward speed manual transmissions having the standard “H” pattern, shall be displayed in view of the driver at all times when a driver is present in the driver's seating position.
[70 FR 38051, July 1, 2005, as amended at 70 FR 75965, Dec. 22, 2005]