Interpretation ID: 18897-2.wkm
Phillip A. Proger, Esq.
Jones, Day, Reavis & Pogue
Metropolitan Square
1450 G Street, NW
Washington, DC 20005-2088
Dear Mr. Proger:
This refers to your meeting with Messrs. Daniel, Myers, and Woods of this agency on October 1, 1998 and to your letter of October 8 to Mr. Myers of my staff.(1) You asked two questions, as discussed below.
Your first question concerned paragraph S5.3.3(b), Federal Motor Vehicle Safety Standard (Standard) No. 105, Hydraulic and electric brake systems, as amended (hereinafter referred to as "New 105").(2) You correctly stated that S5.3.3(b) of New 105 requires a message of malfunction to be stored in the antilock brake system (ABS) if it exists when the ignition is turned to the "off" position (ignition cycle No. 1) so that it again illuminates the malfunction indicator lamp (MIL) when the ignition is next turned to the "on" or "run" position (ignition cycle No. 2). You first asked how long the MIL must remain illuminated after being activated in ignition cycle No. 2. You stated that clarification of this point is essential since certain malfunctions, which you did not specify, can only be detected and confirmed when dynamically tested for at speed, but that S5.3.3(b) appears to require that the MIL remain illuminated indefinitely when a message of malfunction exists. You are correct that S5.3.3(b) so provides.
Paragraph S5.3.3(a) of New 105 provides:
Each indicator lamp activated due to a condition specified in S5.3.1 shall remain activated as long as the malfunction exists, whenever the ignition (start) switch is in the "on" (run) position, whether or not the engine is running (emphasis supplied).
S5.3.3(b) then provides:
For vehicles with a GVWR [gross vehicle weight rating] greater than 10,000 pounds, each message about the existence of a malfunction, as described in S5.3.1(c), shall be stored in the antilock brake system after the ignition switch is turned to the "off" position and the indicator lamp shall be automatically reactivated when the ignition switch is again turned to the "on" position. The indicator lamp shall also be activated as a check of lamp function whenever the ignition is turned to the "on" (run) position. The indicator lamp shall be deactivated at the end of the check of lamp function unless there is a malfunction or a message about a malfunction that existed when the key switch was last turned to the "off" position.
Thus, read together, S5.3.3(a) and (b) provide that the MIL must remain activated as long as the malfunction exists, whether in ignition cycle No. 1 or No. 2. Further, the malfunction message must be stored in the system so that the MIL automatically activates when the ignition is again turned to the "on" position. The MIL must also activate as a check of lamp function any time the ignition is turned to the "on" position, but must deactivate at the end of that check of lamp function, unless a malfunction message was previously stored in the system. Accordingly, whenever the ignition switch is on, regardless of the number of ignition cycles, once the MIL activates in response to a malfunction message, the lamp must remain illuminated until the malfunction no longer exists, however long that may be.
Your second question also concerned illumination of the MIL. You stated that Lucas Varity Light Vehicle Brake Systems (LVBS) believes that once the MIL has been illuminated as the result of a message of malfunction, it would be desirable for the MIL to be deactivated when any vehicle motion is detected. You stated that this approach would provide advisories to drivers, relief drivers, and inspectors while avoiding false positive malfunction indications. You stated that certain malfunctions, again unspecified, cannot be verified until dynamic testing is completed at speeds ranging between 8 and 15 miles per hour (mph). Thus, LVBS prefers to deactivate the MIL once any vehicle motion is detected and illuminate it again only when the existence of a malfunction is confirmed through dynamic testing at speed. Then, as soon as a malfunction is so verified, the MIL will again illuminate.
This question is answered by the answer to question 1 above, namely that the MIL, after momentary illumination for the bulb check function, must remain illuminated if either a malfunction is detected or a message of a malfunction was stored at the end of the previous ignition cycle. The MIL must remain illuminated until it is determined that a system malfunction is no longer present. Note that a message of malfunction stored at the end of an ignition cycle may be deleted from memory if repairs are performed to restore proper system functioning prior to initiation of the next ignition cycle.
We note that the agency addressed the issue of the MIL being either illuminated or extinguished during low-speed driveaway after key-on in the final rule of March 10,1995, 60 FR at page 13246, wherein NHTSA stated:
NHTSA has decided to require the malfunction indicator lamp to activate when a problem exists and not activate when the system is functioning properly. Under this requirement, the indicator lamp is required to provide a continuous indication until a function check of the ABS is completed. The agency believes that this ABS malfunction lamp format, together with the requirement that the system stores malfunctions until the next key-on, is necessary to enable Federal and State inspectors to determine the operational status of an ABS without moving the vehicle.
In its petition for reconsideration of the final rule on this issue, Navistar suggested allowing the vehicle to be in motion at low speed during an ABS system check so that the sensor check could be included before the lamp extinguished. In denying that suggestion, the agency stated at 60 FR 63972:
NHTSA believes that the requirement that the system store malfunctions until the next key-on is necessary to enable Federal and State inspectors to determine the operational status of an ABS without moving the vehicle. . . . Navistar's request to allow the vehicle to be in motion before the lamp extinguishes would impede [Federal Highway Administration's] inspection process to determine the operational status of ABS. The agency therefore has decided to deny Navistar's petition to amend the malfunction lamp protocol to allow the lamp to stay lit until the vehicle is driven.
In a further response to petitions for reconsideration dated March 16, 1998 (63 FR 12660), the agency again addressed the issue of the MIL remaining activated during a low-speed drive away. Kelsey-Hayes requested that the agency reconsider the activation protocol requirements for the MIL in the final rule of March 10, 1995. Kelsey-Hayes stated that allowing the MIL to remain illuminated during a low-speed drive away would serve to verify that the vehicle's wheel speed sensors were properly functioning. NHTSA denied that request, citing three reasons:
First, a standardized protocol would enable Federal and State safety inspection personnel to determine the operational status of ABSs without having to move the vehicle. Second, it would preclude confusion among heavy vehicle drivers relative to how this type of lamp functions. Third, standardization would be consistent with ECE requirements on this subject and would, therefore, be consistent with the goal of international harmonization.
It is clear that NHTSA has repeatedly considered the issue of the continuous illumination of the MIL and has, on each occasion, reiterated its decision to require that the lamp remain illuminated when a malfunction message exists whenever the ignition switch is in the on position, in all ignition cycles, and be extinguished if no malfunction exists. Accordingly, the lamp may not remain illuminated (absent a detected malfunction on a stored malfunction message) pending a sensor check at speed, nor may it be extinguished pending "confirmation" of a malfunction at speed.
I hope this information is helpful to you. Should you have any questions or need additional information, feel free to contact Mr. Myers or Mr. Woods at this address or by telephone at (202) 366-2992 and (202) 366-6206 respectively.
Sincerely,
Frank Seales, Jr.
Chief Counsel
Ref:105
d.5/14/99
1. We note that you sent us three letters dated October 8, 1998, all relating to the October 1, 1998 meeting and all relating to the malfunction indicator lamp protocol of Standard No. 105. We are responding to the three letters separately.
2. The applicable amendments to Standard No. 105 were scheduled to become effective on March 1, 1999. That date was extended, however, until September 1, 1999 by Interim Final Rule; Request for Comments dated February 26, 1999 (64 FR 9446).