ID: nht95-6.49

TYPE: INTERPRETATION-NHTSA

DATE: September 19, 1995

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Milford R. Bennett -- Director, Safety Affairs and Safety & Restraints Center, General Motors Corporation

TITLE: NONE

ATTACHMT: ATTACHED TO 5/19/95 LETTER FROM MILFORD BENNETT (SIGNED BY F. LAUX) TO JOHN WOMACK

TEXT: Dear Mr. Bennett:

This responds to General Motors' (GM's) May 19, 1995 letter asking whether a sunshade device is permitted under the 70 percent light transmissibility requirements of Federal Motor Vehicle Safety Standard (FMVSS) No. 205, Glazing Materials. You describe the device as a screen-like device that is stowed in the back panel shelf area below the rear window and that can be electrically raised and lowered by a driver operated switch. The light transmissibility through the combination of the rear window and the raised sunshade is less than 70 percent. The short answer to your question is that the device is permitted.

Although you note earlier agency interpretations stating that windows with sunshades must still comply with Standard No. 205, you believe that the standard does not apply to your device. You state that those interpretations were distinguishable because the other shading devices were attached to the window, while your device is not.

You are correct in your assertion that installation of your sunshade would not cause a noncompliance with Standard No. 205. The purpose of the 70 percent light transmissibility requirements in Standard No. 205 is to ensure that the driver can see 70 percent of the incident light through the windows that are requisite for driving visibility, under all conditions of lighting. However, the test procedures do not incorporate an in-vehicle test. Instead, they contemplate testing only the glazing itself. Your mesh screen sunshade need not comply with the standard (because it does not meet the definition of glazing) or in combination with the rear window (because it is not attached).

Although our standards do not prohibit this device, we have some safety-related concerns with its use in inappropriate situations. NHTSA hopes that GM plans to take steps to minimize the likelihood that the sunshade will be raised in such situations.

I hope this information is helpful. If you have any further questions, please feel free to contact Paul Atelsek of my staff at this address or by telephone at (202) 366-2992.

ID: nht95-6.5

TYPE: INTERPRETATION-NHTSA

DATE: August 8, 1995

FROM: Eric D. Swanger, PE -- Engineering Manager, Specialty Manufacturing Co.

TO: John Womack -- NHTSA

ATTACHMT: ATTACHED TO 11/21/95 LETTER FROM Samuel J. Dubbin to Eric D. Swanger (A43; Std. 131)

TEXT: Dear Mr. Womack:

Research is performed at Specialty Manufacturing on a continual basis to investigate different means of improving upon the safety of school bus equipment. Recently, an inquiry has been made to Specialty concerning the usage of light-emitting diodes (LED's) on stop arms. Apparently one state feels the usage of LED's to spell out the word "STOP" on the stop arm blade would increase the visibility of the sign in certain weather conditions.

After the engineering department of Specialty Manufacturing manufactured a prototype unit and tested the unit, several questions were raised which we feel need clarification from NHTSA in reference to FMVSS 131. The first being the basic viewing angles of LED's. While LED's have a quicker "on" and "off" time than incandescent bulbs, the overall viewing angle of an LED is extremely limited. Depending upon the placement of the LED's in the stop arm blade, the word "STOP" can vary from being noticeable to being a scattered pattern of lights. Exact placement of the LED's will depend upon the consistency of the manufacturing process. With incandescent lights, the light is very noticeable from all angles and manufacturing consistencies are not at all a concern.

The second issue is the legibility of the LED "STOP" at any given distance. Opinions of many casual onlookers asked to critique the LED sign when lit, seem to indicate that the letters are not large enough nor spaced far enough apart to be discernible at larger distances. Since the size of the letters is clearly defined by FMVSS 131, it appears that standard may have to be revised in order to ensure that "STOP" is legible at greater distances.

P2

The third issue is that of safety equipment consistency. Currently, all stop arms must have the word "STOP" displayed on the stop sign itself. The red lights are optional. The addition of another optional method of lighting may lead to confusion and subsequent passing violations due to visiting drivers being unfamiliar with state or county practices of school bus identification.

The development of an LED stop arm appears to our company to be quite expensive at the out set, and we are definitely concerned with the viewing angle, legibility from certain distances, and that consistences provided by FMVSS 131 could be in jeopardy.

I'm asking if you would please give us your interpretation of FMVSS 131 and the use of LED lights outlining the word "STOP." Specialty Manufacturing would be available to help in any standard research, manufacturer input, etc., as we have done in the past.

If I may be of any assistance, please do not hesitate to call me at 1-800-951-7867.

ID: nht95-6.50

TYPE: INTERPRETATION-NHTSA

DATE: September 19, 1995

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: David Seagren -- Dealer Principal, Pony Express Dodge, Inc.

TITLE: NONE

ATTACHMT: 12/8/95 letter from Samuel J. Dubbin to Peter F. Marthy (A43; Part 580)

TEXT: This is in response to your letter sent to this office by telefax on September 12, 1995. In your letter, you ask whether it is permissible to alter an odometer that registers kilometers rather than miles by multiplying the kilometer reading by .62, when there had been a previous attempt to convert the reading to miles. Your letter states that the earlier attempt resulted in the odometer being set back to the equivalent in miles but the odometer continued to register distance in kilometers.

As you are aware from a Federal Register notice faxed to you by Eileen Leahy of this office, the National Highway Traffic Safety Administration (NHTSA), the Federal agency with responsibility for the odometer disclosure regulations promulgated pursuant to the Truth in Mileage Act of 1986 (TIMA) has stated that it is permissible to reset the odometer from kilometers to miles by multiplying the number of kilometers shown on the odometer by .62, and that it is also permissible to certify that number of miles as "actual" when completing the odometer disclosure statement when ownership of the vehicle is transferred.

The rationale for this policy is that "mileage" is defined in the Federal regulations as distance traveled, and it is permissible to express the number either in miles or metrically if it is known that it reflects the actual distance traveled and that the disclosure of the odometer reading specifies which system of measure (miles or kilometers) is being used. Because the conversion from kilometers to miles can be accurately made simply by multiplying the kilometers on the odometer by 0.62, the agency believes that there is little likelihood that permitting odometer readings that have been converted from kilometers to miles to be recorded as "actual mileage" will result in an inaccurate or misleading representation of the distance a vehicle has traveled.

The situation you describe is more complicated because a previous owner of the vehicle in question had already set back the odometer to the mileage equivalent after purchasing it with an odometer reading in kilometers, but according to your letter did not execute properly the procedure necessary to make the odometer register miles rather than kilometers while being driven. The result of this error has been the addition of kilometers to a figure that reflected miles rather than kilometers traveled.

In order to permit recording of a conversion of the present odometer reading from kilometers to mileage as "actual mileage" in this circumstances, two criteria must be satisfied. First, it must be apparent that the calculation at the time of the first conversion was done properly so that it reflects the actual number of miles the vehicle had traveled at that time. From the documents you submitted reflecting the events that occurred prior to your purchase of the vehicle, it appears that the previous owner properly converted kilometers to miles. Accordingly, the first criterion is satisfied.

It is then necessary to establish that the reading now shown on the odometer accurately represents the distance traveled by the vehicle since the first attempted conversion. There is no indication in any of the documentation you furnished that there have been any intervening alterations to the odometer or changes in the way it has recorded distance that would alter the accuracy of its current reading. In addition, you state that since your company has owned the vehicle, the odometer has consistently operated in a way that shows that it was registering kilometers rather than miles. Based on these factors, it appears that it will be possible for you to ascertain with accuracy the distance the vehicle has traveled since the first conversion from kilometers to miles was made.

The proper way to do this conversion is to subtract the number shown as the reading in miles as a result of the calculation made at the time conversion was first attempted, from the number showing on the odometer when you transfer ownership of the vehicle. The result will be the total kilometers the vehicle has traveled since that time. To arrive at the number of miles traveled since the attempted conversion, the result of that subtraction is to be multiplied by 0.62 as described above. In turn, the number resulting from that multiplication is added to the number of miles at the time of the first conversion and the sum is the total number of miles traveled by the vehicle at the time of transfer. You may then properly certify on the odometer disclosure statement when you transfer ownership of the vehicle that that number is its actual mileage.

Because the Kansas Motor Vehicle Department asked that you contact this office for our interpretation of the proper way to handle the sale of this vehicle under the Federal odometer disclosure regulations, it would be advisable to provide that office with a copy of this letter either before or at the time of your application for a new title.

I hope this information is helpful. If you have any further questions about this matter, please contact Eileen Leahy, an attorney in this office, at the address shown above or at (202)366-5263.

(9/12/95 telefax from David Seagren to NHTSA is not available.)

ID: nht95-6.51

TYPE: INTERPRETATION-NHTSA

DATE: September 20, 1995

FROM: Jonathan P. Reynolds -- Executive Vice President, General Counsel, Cosco

TO: Deirdre Fujita -- NHTSA

TITLE: Cosco's Petition for Reconsideration Final Rule - Federal Register Volume 60 Number 129 Docket No. 74-09; Notice 42

ATTACHMT: ATTACHED TO 10/24/95 LETTER FROM JOHN WOMACK TO JONATHAN P. REYNOLDS (REDBOOK 4; PART 553; 74-09, N42-005-02)

TEXT: Dear Ms. Fujita:

In accordance with the requirements set forth in the Federal Register announcement of the subject Final Rule, Cosco submitted its petition for reconsideration in a timely fashion. The petition was transmitted via Federal Express on Friday, August 4, 1995, for next day delivery, on Monday, August 7, 1995.

Although we have not been formally advised, we have learned informally that NHTSA may contend that the petition was not received until August 10. We have confirmed with Federal Express that in fact the petition was delivered on August 7, 1995, and signed for by NHTSA employee T. Proctor. Attached are the Federal Express forms signed by each recipient of a Federal Express delivery, showing T. Proctor under item 15 on page 2 for August 7, 1995. Federal Express has confirmed that this package was in fact delivered to NHTSA on August 7, 1995.

Please confirm in writing that Cosco's petition is being deemed as timely received and that a response to the petition will be forthcoming in a timely fashion. Given the scope of the Final Rule and the very important concerns involved, Cosco assumes that the agency wishes to promptly address the issues raised by Cosco in its petition.

Please contact me if you require any further information or have any questions. I look forward to your prompt reply to this inquire.

(Federal Express forms omitted.)

ID: nht95-6.52

TYPE: INTERPRETATION-NHTSA

DATE: September 20, 1995

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Mr. Yoshiaki Matsui -- Manager, Automotive Equipment, Legal & Homologation Section, Stanley Electric Co., Ltd.

TITLE: Re: Headlamp System Containing Fog Lamp

ATTACHMT: ATTACHED TO 8/11/95 LETTER FROM YOSHIAKI MATSUI TO CHIEF COUNSEL, NHTSA

TEXT: Dear Mr. Matsui:

This replies to your letter of August 11, 1995, with reference to possible headlamp systems that produce a fog lamp beam, as well as upper and lower beams. According to your letter, "the fog lamp is reciprocally incorporated with the high beam headlamp, using one dual-filament bulb (ex.; HB2). The high beam and the fog lamp will not be lit simultaneously." You refer to paragraph S5.1.3 of Federal Motor Vehicle Safety Standard No. 108 and conclude that "such a combination will not impair the effectiveness of the headlamp."

We agree, with respect to the headlamp itself, that a fog lamp operating simultaneously with the lower beam will not impair the effectiveness of the lower beam's photometrics and ability to illuminate the roadway. We view this as a supplement to the lower beam. However, under S5.1.3, the question is whether the fog lamp, either operating alone or when the lower beam headlamp is activated, will impair the effectiveness of any front lighting equipment that is required by Standard No. 108. The responsibility for the determination of compliance with S5.1.3 is not Stanley's, but that of the manufacturer of the vehicle in which the combination headlamp is installed, who must certify that its vehicle meets all applicable U.S. Federal motor vehicle safety standards.

The other front lighting equipment required by Standard No. 108 consists of parking lamps and turn signal lamps. The amber parking lamps serve to mark a vehicle, a function incidentally served by white fog lamps. Thus we do not believe that the Stanley headlamp would impair the effectiveness of parking lamps in any position in which the headlamp may be installed on the front of a vehicle.

The situation differs with respect to turn signal lamps. A vehicle manufacturer must take care to ensure that a vehicle on which the combination headlamp is installed conforms to the requirements of Standard No. 108 and to paragraph 5.1.5.4 of SAE Standards J588 NOV84 or J1395 APR85, the two turn signal standards incorporated by reference in Standard No. 108. Paragraph 5.1.5.4 treats the relationship between luminous intensity and photometrics "where the front turn signal is mounted in close proximity to the low beam headlamp or any additional lamp used to supplement or used in lieu of the low beam, such as an auxiliary low beam or fog lamp." It does this by establishing luminous intensity multipliers based upon the distance that separates the lamps. For example, if the space between the front turn signal and the lighted edge of the fog lamp is 75 mm to less than 100 mm, the photometric requirements for a front turn signal lamp are 1.5 times more than those required when the spacing is 100 mm or more (Paragraph S5.3.1.7 of Standard No. 108 requires the multiplier at this distance to be 2.5 when the lamp is a lower beam headlamp rather than a fog lamp).

Finally, as a cautionary note, we believe that Stanley should evaluate the glare potential of the headlamp when the fog lamp and lower beam are operating simultaneously, as it is important to safety that oncoming drivers not be distracted or discomforted in the operation of their vehicles.

If you have any further questions, you may refer them to Taylor Vinson of this Office (phone: 202-366-5263).

ID: nht95-6.53

TYPE: INTERPRETATION-NHTSA

DATE: September 20, 1995

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Dennis G. Moore -- President, Sierra Products, Inc.

TITLE: NONE

ATTACHMT: ATTACHED TO 7/31/95 LETTER FROM DENNIS G. MOORE TO NHTSA CHIEF COUNCIL

TEXT: Dear Mr. Moore:

This responds to your letter of July 31, 1995, with respect to lens area requirements of amber turn signal lenses.

You believe that "by reducing the minimal area of the Amber Turn Signal light lens from 12 square inches to approximately 8 square inches or 6 square inches the U.S. would have more practical rules for U.S. Exports at no expense to Safety. You ask that, "If NHTSA's Legal Council feels this error should be corrected through the Petitioning Process, I ask that this writing be considered a 'Petition for Change of FMVSS # 108 Request'".

Standard No. 108 contains two relevant regulations, one applicable to vehicles whose overall width is less than 80 inches, and one to those whose overall width is 80 inches or more.

Under paragraph S5.1.1.26(a), the functional lighted lens area of a single turn signal lamp of either red or amber on a vehicle whose overall width is less than 80 inches shall be not less than 50 square centimeters. This is approximately 8 square inches. Therefore, no rulemaking is required to implement your recommendation.

The standard that applies to turn signal lamps on vehicles whose overall width is 80 inches or more is SAE Standard J1395 APR85, incorporated by reference in Standard No. 108. Under its paragraph 5.3.2, the functional lighted lens area of a single turn signal lamp shall be at least 75 square centimeters, or approximately 12 square inches. Therefore, rulemaking is required to implement your recommendation.

We are transmitting your letter to our Office of Safety Performance Standards for consideration as a petition for rulemaking to change the minimum lens area requirement for turn signal lamps on large vehicles from 75 to 50 square centimeters. On September 4, 1995, I determined that your letter met our procedural requirements for a petition. Accordingly, the Office of Safety Performance Standards will inform you not later than January 1, 1996, whether your petition has been granted.

If you have any questions, you may refer them to Taylor Vinson of this Office (202-366-5263).

ID: nht95-6.54

TYPE: INTERPRETATION-NHTSA

DATE: September 23, 1995

FROM: Margaret Fisher, MD -- Kaiser Permanente

TO: James J. Gregorio

TITLE: NONE

ATTACHMT: Attached to 11/7/95 letter from Samuel J. Dubbin to James J. Gregorio (VSA 108 (a)(2)(A); A43; Std. 207; Std. 208)

TEXT: I am writing to request authorization to modify the car seat in my 1992 Plymouth Acclaim in order to accomodate my physical handicap. Presently, my car is equipped with hand controls which alleviate a condition of chronic tendinitis in my right ankle. Unfortunately, there is practically no room between the hand controls and my knees. My knees constantly bang up against the hand controls. The resulting consequence is that I now have tendinitis in both knees. Modifying the car seat will allow me to push the seat back far enough to give space to my injured knees. Enclosed is a statement from my physician validating my medical condition. Should you have any questions, please feel free to call me at your convenience. Your prompt reply to this painful condition would be greatly appreciated. Thank you.

Attachment

September 22, 1995

To Whom It May Concern:

Mr. James Gregorio is under my care for tendinitis of the right ankle and both knees. Recovery could take up to several years.

Sincerely yours,

Margaret Fisher, MD Kaiser Permanente

ID: nht95-6.55

TYPE: INTERPRETATION-NHTSA

DATE: September 25, 1995

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Dennis G. Moore -- President, Sierra Products, Inc.

TITLE: NONE

ATTACHMT: ATTACHED TO 7/31/95 LETTER FROM DENNIS G. MOORE TO NHTSA CHIEF COUNCIL (OCC 11123); ALSO ATTACHED TO LETTER DATED 3/4/77 FROM FRANK BERNDT TO DENNIS G. MOORE

TEXT: Dear Mr. Moore:

This responds to your letter of July 31, 1995, on the subject of "optical combination" as that term is used in Motor Vehicle Safety Standard No. 108.

You enclosed a copy of a letter sent to you from this Office on March 4, 1977, and refer to a "Rider" in "a proposed change [around 1990] that had no relevance to this subject, whereas the Rulemakers added the expression, 'NOT TO SHARE THE SAME HOUSING.'" You ask how "[using] the Scientific Argument and discussions I submitted back in 1975, 1976, and 1977, and the Re-Interpretation letter sent me, how can NHTSA support the SAME HOUSING definition they currently support."

You are talking of events of 18 to 20 years ago that are no longer relevant today. The definition that NHTSA supports contains no reference to lamp housings. Standard No. 108 was amended four years ago, in 1991, to clarify that the term "optical combination" is to be interpreted as defined by SAE Information Report J387 Terminology - Motor Vehicle Lighting NOV87. Under the SAE definition, optical combination results when a lamp "has two or more separate light sources, or a single light source that operates in different ways (e.g., a two-filament bulb)", and when "its optically functional lens area is wholly or partially common to two or more lamp functions." It is immaterial to this definition whether the light sources are in the same or different housings. I enclose a copy of a rulemaking proposal and final rules dealing with this issue that were published on November 6 and 8, 1990, and June 7 and November 7, 1991.

If you have further questions, you may refer them to Taylor Vinson of this Office by FAX (202-366-3820).

ID: nht95-6.56

DATE: October 26, 1995

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Hugh J. Bode, Esq. -- Reminger & Reminger

TITLE: NONE

ATTACHMT: ATTACHED TO 8/21/95 LETTER FROM HUGH J. BODE TO JOHN WOMACK

TEXT: Dear Mr. Bode:

This responds to your letter concerning whether 49 U.S.C. @@ 30101 et seq. (formerly the National Traffic and Motor Vehicle Safety Act) requires a motor vehicle manufacturer to ensure that its vehicle continues to comply with applicable Federal motor vehicle safety standards (FMVSSs) after the first retail purchase of the vehicle.

You specifically ask about FMVSS No. 124, "Accelerator Control Systems," and its application to a 1988 Dodge Ram 50 pickup truck. It appears from the questions you ask that corrosion developed inside the carburetor of the pickup truck at some point during the life of the vehicle, such that the carburetor would not return to idle in accordance with the requirements of Standard No. 124.

You asked us to "confirm the accuracy" of a number of statements. Your first statement, concerning the application of the FMVSSs generally, is as follows:

As we understand it, former @ 108(a) (1) (A) of the National Traffic and Motor Vehicle Safety Act, 49 U.S.C. @ 30112(a), prohibits any person from manufacturing, selling or introducing into commerce any new motor vehicle unless the vehicle is in conformity with all applicable FMVSS. However, the Safety Act further provides that the requirement that a vehicle comply with all applicable FMVSS does not apply after the first purchase for purposes other than resale, i.e., the first retail sale of the vehicle. Safety Act former @ 108 (b) (1), 49 U.S.C. @ 30112 (b) (1). After the first retail sale, the only provision in the Safety Act that affects a vehicle's continuing compliance with an applicable FMVSS is set forth in former @ 108(a) (2) (A), 49 U.S.C. @ 30122(b), which prohibits certain persons from knowingly rendering inoperative a device installed in a motor vehicle in compliance with an applicable FMVSS.

Your general understanding is correct. However, a manufacturer has responsibilities in addition to those in @ 30112, that may bear upon on "continuing compliance" of its vehicle. Under @@ 30118-30122 of our statute, each motor vehicle manufacturer must ensure that its vehicles are free of safety-related defects. If NHTSA or the manufacturer of a vehicle determines that the vehicle contains a safety-related defect, the manufacturer must notify purchasers of the defective vehicle and remedy the problem free of charge.

This is not to say that the development of the corrosion in the carburetor necessarily constitutes a safety-related defect. Rather, we acknowledge the possibility of such a finding in certain circumstances, such as where the corrosion developed unreasonably quickly in the vehicle and the problem was such that it could lead to crashes involving injuries or fatalities.

State law could also be relevant to this issue. For example, as part of its vehicle inspection requirements, a State could require that the accelerator control systems on vehicles "continue to comply" with the requirements of Standard No. 124.

With the above discussion in mind, I will now address your other four questions on Standard No. 124.

Question 1. We ask that NHTSA confirm that FMVSS 124 is a standard that a given vehicle must comply with only at the time of the first retail sale of the vehicle.

As explained in our answer above, your understanding is correct with regard to our requirements (49 U.S.C. @ 30112). There may be State requirements that apply.

Question 2. We ask NHTSA to confirm that if a carburetor installed in a 1988 Dodge Ram 50 pickup truck met all the requirements of FMVSS 124 at the time of the truck's first retail sale, but, after the sale, due to in-service conditions, corrosion developed inside the carburetor so the carburetor would not return to idle in accordance with the requirements of S5.1, S5.2, and S5.3 of FMVSS 124, that circumstance would not render the vehicle in violation of FMVSS 124.

Your understanding is essentially correct. As permitted by Federal law, Chrysler sold the truck based upon its own certification of compliance with FMVSS No. 124. That corrosion developed in the system may or may not be relevant with respect to the existence of a safety-related defect.

Question 3. We ask NHTSA to confirm that all of the performance standards imposed by FMVSS 124 are contained in S5.1, S5.2 and S5.3 of FMVSS 124 and that S2 headed PURPOSE does not impose any separate regulatory obligation beyond those contained in S5.

While your understanding is essentially correct, note that Standard No. 124 and other motor vehicle safety standards are minimum performance standards.

Question 4. We ask you to confirm that the performance standard set forth in FMVSS 124 does not contain any requirement relating to durability or corrosion resistance.

Standard No. 124 does not specify a test for corrosion resistance. It is unclear what you mean by "durability." The requirements of the standard must be met when the engine "is running under any load condition, and at any ambient temperature between - 40 degrees F. and + 125 degrees F. . ." (S5) In addition to the performance regulated by Standard No. 124, each manufacturer must ensure that its motor vehicle does not have a safety-related defect.

If you have any questions about the information provided above, please contact Dorothy Nakama of my staff at this address or at (202) 366-2992.

ID: nht95-6.57

DATE: October 30, 1995

FROM: John Womack -- Acting Chief Counsel, NHTSA

TO: Larry W. Strawhorn -- Vice President of Engineering, American Trucking Associations

TITLE: NONE

ATTACHMT: ATTACHED TO 9/6/95 LETTER FROM LARRY W. STRAWHORN AND EARL EISNHART TO JOHN G. WOMACK

TEXT: Dear Mr. Strawhorn:

This letter responds to your request for an interpretation of the antilock malfunction indicator requirements set forth at S5.2.3.3 of Standard No. 121, Air Brake Systems. This provision explains the situations in which the trailer lamp malfunction indicator must remain activated. Section S5.2.3.3 reads as follows:

S5.2.3.3 Antilock Malfunction Indicator. Each trailer (including a trailer converter dolly) manufactured on or after March 1, 1998 and before March 1, 2006 shall be equipped with a lamp indicating a malfunction of a trailer's antilock brake system. Such a lamp shall remain activated as long as the malfunction exists whenever the power is supplied to the antilock brake system. The display shall be visible within the driver's forward field of view through the rearview mirror(s), and shall be visible once the malfunction is present and power is provided to the system. (Emphasis added.).

In particular, you request that the agency confirm your belief that the lamp activation pattern for trailers may be such that the bulb be ON when the antilock system is working properly and OFF when a malfunction exists, the antilock system is not getting electrical power, or the lamp bulb is burnt out. You contended that such an activation pattern provides a fail safe pattern i.e., it will signal an inoperative antilock system even when the system is not receiving electrical power or the lamp bulb is burnt out.

NHTSA disagrees with your suggested reading of the malfunction indicator requirements. Such a reading would be inconsistent with S5.2.3.3's language stating that the lamp must "remain activated as long as the malfunction exists whenever the power is supplied to the antilock brake system." As with other malfunction indicators, the agency intends the malfunction indicator to activate when a malfunction exists and not activate when the system is functioning properly. To require otherwise would be inconsistent with our requirements for other indicators and thus would create confusion. Please note that NHTSA provided a lengthy discussion about the issue of a malfunction indicator's activation protocol in the March 10, 1995 final rule. (60 FR 13216, 13246) The agency stated that in response to an ABS malfunction, a trailer or tractor indicator must activate and provide a continuous yellow signal. The agency explained that such a common indicator pattern standardizes the activation format, thus reducing ambiguity and confusion and expediting Federal and State inspections.

I hope this information has been helpful. If you have any other questions, please contact Marvin Shaw of my staff at this address or by phone at (202) 366-2992.