Skip to main content
Search Interpretations

Interpretation ID: nht94-2.93

TYPE: INTERPRETATION-NHTSA

DATE: May 17, 1994

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Michael Love -- Manager, Compliance Porsche Cars North America, Inc.

TITLE: None

ATTACHMT: Attached To Letter Dated 1/21/93 From Michael Love To Paul Jackson Rice (OCC-8259)

TEXT: Dear Mr. Love:

This responds to your request for an interpretation of Federal Motor Vehicle Safety Standards (FMVSS) No. 101; Controls and displays and No. 102; Transmission shift lever sequence, starter interlock, and transmission braking effect. I apologize for the d elay in our response. You asked about the standards in connection with three options your company is considering for changing its "Tiptronic" automatic transmission system.

By way of background information, the National Highway Traffic Safety Administration (NHTSA) does not provide approvals of motor vehicles. Under the National Traffic and Motor Vehicle Safety Act, it is the responsibility of the manufacturer to ensure th at its vehicles meet applicable requirements. The following represents our opinion based on the facts provided in your letter.

The current Tiptronic automatic transmission system can be described as follows:

The shift lever is located in the middle console, where it can be moved along either of two slots which are located essentially parallel to the longitudinal axis of the vehicle. The left slot (automatic function) is essentially the same as a conventiona l automatic transmission gear shift lever, with the following positions (in order): P R N D 3 2 1. At the D position (only) of the left slot, the gear shift lever can be transferred to the M (manual) position of the right slot (manual function). The ri ght slot consists of the following positions (in order): + M -. When the gear shift lever is in the right slot, the driver can select a higher gear (+) or lower gear (-) by tapping the shift lever. The shift lever always returns to the "M" position aft er being tapped.

2

There are two gear position displays, one on the middle console and the other on the instrument panel. The middle console display, which is not illuminated, shows each of the 10 positions where the shift lever may be placed. It also shows the position which is selected. The display on the instrument panel, which is illuminated, has two columns which correspond to the slots on the middle console. However, while the left column (corresponding to the left slot or automatic function) shows the positions P R N D 3 2 1, the right column (corresponding to the right slot or manual function) shows the positions 4 3 2 1. In other words, the right column portion of the display shows the available gears and the actual gear selected rather than + M -. For bot h columns, the selected position or gear is indicated by an illuminated arrow.

In your letter to NHTSA, you indicate that Porsche is considering the following three options for modifying its system:

Option 1. The first proposed modification would eliminate the 3, 2 and 1 positions on the left (automatic) slot.

Option 2a. The second proposed modification would eliminate the 3, 2 and 1 positions on the left (automatic) slot and the + and - positions on the right (manual) slot. Gear selection in the manual mode would be accomplished not by the shift lever but by shift rocker switches on the steering wheel.

Option 2b) The third proposed modification would provide only one slot with the following positions (in order): P R N D M D. In the M position, gear selection would be accomplished by shift rocker switches on the steering wheel.

For each of the proposed modifications, the shift lever positions would be labeled on the middle console, in the same manner as the current system. Similarly, the middle console would not be illuminated. The instrument panel display would not change for any of the options.

You ask a number of questions concerning whether the Tiptronic system, as modified under options 1, 2a and 2b, would comply with Standards No. 101 and 102. The issues raised by your letter are addressed below.

I will begin by identifying the requirements of Standards No. 101 and No. 102 which are relevant to your questions. Section S3.1.4.1 of Standard No. 102 states:

Except as specified in S3.1.4.3, if the transmission shift lever sequence includes a park position,

3

identification of shift lever 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:

(a) The ignition is in a position where the transmission can be shifted.

(b) The transmission is not in park.

S3.1.4.4 states:

Effective September 23, 1991, all 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 infor mation may be provided.

Standard No. 101 specifies requirements for the location, identification and illumination of automatic gear position indicators. Section S5.1 requires that gear position display must be visible to the driver under the conditions of S6. Section S5.3.1 an d Table 2 of the standard together require that automatic gear position displays be illuminated whenever the ignition switch and/or the headlamps are activated. The entry in Table 2 concerning the automatic gear position display references Standard No. 102. In a April 2, 1989 letter to Porsche concerning the Tiptronic system, we concluded that, given the reference in Standard No. 101 to Standard No. 102, where multiple gear position displays are provided and one complies with Standard No. 102 and the others do not, the requirements of Standard No. 101 must be met for the display which complies with Standard No. 102.

With this background in mind, I will discuss the existing Tiptronic system and the three possible modifications. For the reasons discussed above and in our April 2, 1989 letter, while multiple gear position displays are permitted, one such display must comply with all of the relevant requirements of Standards No. 101 and No. 102. Since your console display is not illuminated, it would obviously not comply with Standard No. 101. I will therefore address your letter in the context of whether the instru ment panel display meets the requirements of the two standards. I assume that the instrument panel is activated during the times specified by Standard No. 102.

Under section S3.1.4.1 of Standard No. 102, there must be a display of all of the shift lever positions in relation to each other, and there must be an indication of the position that the driver has selected. In our April 2, 1989 letter, we stated that your design has the following ten shift lever

4

positions: P R N D 3 2 1 + M -. We noted that the right column of the alternative instrument panel displays identified in your letter showed either 4 3 2 1 or 4 3 M 2 1 instead of + M -. We concluded that if the instrument panel display was to be used to meet the requirements of Standard No. 102, it would be necessary for the display to show the 10 actual shift lever positions, including + M -.

Porsche evidently did not follow the opinion provided in that letter, since Porsche neither provided illumination for the console display nor showed the 10 actual shift lever positions, identified in our letter, on the instrument panel display. While we do not understand the reason for this decision by Porsche, we believe that one could reasonably argue that the + and - locations are not really shift lever "positions," since the shift lever cannot be left in those locations. Under this view, + M - cou ld be seen as "one" shift lever position, which is represented on the instrument panel by 4 3 2 1. We would accept this as an alternative way of characterizing the current Tiptronic system, and are therefore not aware of any compliance problems.

I will now turn to the three possible modifications. Once again, since the non-illuminated console display would not meet the requirements of Standard No. 101, the relevant question is whether the instrument panel display meets the relevant requirements of Standards No. 101 and No. 102. A common problem for all three options would be that the instrument panel display retained from the original Tiptronic system would not correspond to the shift lever positions of the modified designs. This could be co rrected for options 1 and 2a simply by deleting the 3 2 1 portion of the left column. A more complicated correction would be needed for option 2a, since the display would need to show the following positions in relation to each other: P R N D M D.

I have several other comments on your letter. You stated that for all three options, Porsche believes that it is not necessary to have the shift lever positions 3, 2 and 1, or to necessarily display those positions if selected automatically in the D pos ition, as long as they as displayed when selected manually by use of the shift lever (in option 1) or shift rocker switch(es) (in options 2a and 2b). Porsche is correct that it is unnecessary to provide shift lever positions 3, 2 and 1. Moreover, to th e extent that such shift lever positions are not provided but the gears are instead selected automatically in the D position or manually in the M position by tapping the shift lever or shift rocker switch, it is unnecessary to display the gears.

You also stated the following:

5

Porsche believes that under options 2a and 2b, both the shift lever and the shift rocker switch(es) would be considered as "shift levers" during the period when they are capable of changing the transmission position. The "shift lever position" would the n be defined as the transmission position, or mode of operation, that was selected by manipulation of any combination of "shift levers." It follows then that identification of "shift lever position" would entail identifying the distinct transmission oper ating modes, in relation to each other and the specific mode selected. . . .

For options 2a and 2b, Porsche believes it is not necessary to illuminate the shift rocker switches, just as it is not necessary to illuminate the shift lever, under the provisions of FMVSS 101, as long as the display in the speedometer showing transmiss ion position is illuminated.

We would not view the shift rocker switch(es) as shift levers under any circumstances. Instead, for the vehicle designs at issue, the lever provided on the middle console would be the only shift lever. When the shift lever is in the "M" position, the s hift rocker switch(es) simply permit manual shifting that is akin to the automatic shifting that occurs when the shift lever is in the "D" position. The rocker switch(es) could not be used to shift the transmission to P, R or N. Under these circumstanc es, we view the rocker switch(es) as a control which is auxiliary to the shift lever and unregulated by Standard No. 102. I note that we might take a different position if the rocker switch(es) permitted the transmission to be shifted to P, R or N, sinc e Standard No. 102 includes requirements to prevent shifting errors. I also note that Standard No. 101 does not require transmission shift levers or controls which are auxiliary to shift levers to be illuminated.

I hope you find this information helpful. If you have further questions, please contact Dorothy Nakama of my staff at this address or by telephone at (202) 366-2992.

Sincerely,