Search Interpretations

Interpretation ID: nht81-2.48

DATE: 07/16/81

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: CSMPCO Corporation

TITLE: FMVSS INTERPRETATION

TEXT: Thank you for your letter of March 3, 1981, providing additional information about the "Downshift Warning System Kit."

After reviewing this information and the points you make concerning Federal Motor Vehicle Safety Standard No. 108, we wish to point out that the pertinent provisions of this standard are S4.1.3 and S4.5.4. For your information, a copy of Standard 108 is enclosed.

You will note that S4.1.3 provides that: "No additional lamp, reflective device or other motor vehicle equipment shall be installed that impairs the effectiveness of lighting equipment required by the standard." Further, you will note that S4.5.4 provides that: "The stop lamps on each vehicle shall be activated upon application of the service brakes." This means that your system must not impair the effectiveness of the stop lamps that are original equipment on the vehicle, and that any application of the service brakes that does not activate the stop lamps would be inconsistent with Federal requirements. As we have made no formal study of your system, you will have to determine whether a vehicle on which it is installed would meet Standard No. 108.

Also enclosed for your information is a copy of the National Traffic and Motor Vehicle Safety Act. Section 108(a)(2)(A) is interpreted to mean that the installation of your system on a used vehicle by a person other than its owner must not render inoperative in whole or in part, the stop lamp system. However, the prohibitions of the Act and the standard do not cover sale of your system as an aftermarket device nor its installation solely by the vehicle owner. Use of it is subject to State regulation.

We would also like to call your attention to the agency's study: "Field Test Evaluation of Rear Lighting Deceleration Signals - Analytical and Experimental Studies (1979)" (DOT HS 805 061). We urge that you obtain a copy of this report and consider it carefully with regard to your system. You may obtain a copy by writing to the National Technical Information Service, Springfield, Virginia 22161.

The agency has tentatively decided that a single high-mounted auxiliary stop lamp is the most effective way of preventing rear end collisions and has proposed that such be made available both as original equipment and in the aftermarket. I enclose a copy of the proposal for your consideration.

ENCLS.

CSMPCO CORPORATION

March 3, 1981

Frank Berndt, Chief Counsel Office of Chief Counsel, NOA-30 National Highway Traffic Safety Administration

Dear Mr. Berndt:

Compliance status of the "Chicoine Downshift Warning System Kit" with Federal Motor Vehicle Safety Standards Nos. 105, 108 and 121.

In your letter of November 14, 1980 you informed me:

* Your review of standard Nos. 105 and 121 show that installation of the kit on a vehicle would not render it noncompliant with them.

* I regard to the lighting standard No. 108, you have several questions for me to answer.

But first, I wish to inform you that I have added a "Conditioned Availability" ancillary system, to the basic kit (return samples). It is a permissive concept introduced to guard against the main system's abuser by its user(s), whether the attempt(s) is inadvertently or maliciously perpetrated.

If you will, please carry the evaluation of compliance to the lighting standard No. 108, using my up-graded system.

I have two versions to present of the ancillary system for the compliance evaluation:

First version: Vacuum Control/engine intake manifold's high vacuum condition triggers, a normally openned, permissive switch's closing. The switch is wired in series with the gear shift knob switch, the closing of both switches is required for the activation of the brake lights.

A vacuum delay valve and a vacuum control valve are added to the ancillary system, to give it a time delay effect that will reduce the system sensitivity to the intake manifold vacuum fast variances. This way an operator can upshift without incurring activation risks of his vehicle brakelights.

1) Delay Valve

A delay valve is fitted in the vacuum line between/near the permissive vacuum-operated switch and the present vacuum control valve. The delay valve is an air flow (vacuum) restrictor, it allows unrestricted flow of air one way and impeded flow the other way. It is necessitated for protection continuity in upshift operation.

2) Present vacuum control valve

The preset control valve is vacuum operated and is fitted in the vacuum line between/near the delay valve and the intake manifold. The preset vacuum control valve closes when the vacuum drops by 5" hg. below the triggering vacuum setting of the permissive vacuum-operated switch. It is necessitated for protection continuity in upshift operation.

Second version: Electronic control/the control device's logic reads the vehicle's deceleration rate and compares it to the manufacturer selected rates (i.e.: 1.5 mph/sec. is acceptable). And as long as the vehicle deceleration rate matches or exceeds the device's set rate, the control device enters and remains into an available operative mode. With the electronic control device in an available operative mode the vehicle's operator can then activate his vehicle's brakelights by using the gearshift switch.

Hall Effect Devices or Wire Coils are used with magnets to generate signals of vehicle velocity to the electronic control device. The takeoffs are from the vehicle's drive shaft or the vehicle speedomaster cable.

A power transistor that is built-in with the electronic control device, is used instead of the electrical-mechanical relay found in the basic kit.

To your first question: "We would like to know if your system prevents the turn signal lamps from flashing, in lamps combining stoplamp and turn signal lamps."

The answer is no. My system will not prevent the turn signal lamps from flashing in lamps combining stoplamps and turn signal lamps.

First reason) The brake switch is not a controlling component for the turn signal lamps flashing operation(s).

Second reason) The kit's relay contact are wired in parallel with the brake pedal stoplamps switch's tabs in other words, the existing switch is simply wirejumped and the kit's relay switch is substituted for the existing brake switch.

I have a '78 Fiesta-Sport Model and it has the lamps combining stoplamps and turn signal lamps that your question refers to. Closing of the brake pedal switch does not prevent the turn signal lamps from flashing, nor does the closing to the kit relays contact prevent the turn signal lamps from flashing. I carried the experience in my garage.

Reply to your second question and closing request: "We would like clarification whether the system activates the stop lamps by pushing the button alone or whether actual motion of the gear shift lever is also required. If the former, we would appreciate your views on possible abuses) of the system, . . . . "

Your second question and closing request convey a message of concern for abuse(s) of the system. That message has influenced my decision to supplement my basic kit with the conditioned availability ancillary system, both versions are automated, beyond operator's control, and work on a permissive concept basis to keep in check main system's abuses.

The content in your second question is a good example of conditioned availability -- the motion of the shift lever be reflected as a condition to fulfill for the system operativeness. But I have not selected as a requirement the motion of the shift lever for the system operativeness.

I have given consideration to the following points:

1) The gear selection(s) for an upshift or a downshift in vehicle(s) equipped with a manual transmission is left to the operator's discretion and vehicle's demand(s).

2) The traffic flow pattern(s) does very i.e.: A traffic flow pattern may dictate a downshift:

* for an acceleration of the vehicle

* for a deceleration of the vehicle

3) The cost of retrofitting of the vehicles already on the roads.

4) The selected permissive ancillary systems' operations:

* are to be fully automated

* are to be controlled by inputs that are relating to the vehicle modal status of acceleration and deceleration.

* in case of component(s) failure, the system is to become inoperative, the fail safe concept.

5) The activation of the downshift warning system kit is to remain a manual, conscious operation by the vehicle operator.

6) The language of the vehicles' stoplamps: To the non-lead driver, the following message have become universal standards, for the vehicles moving on relatively flat grade.

1. Stoplights OFF - Brakes OFF - STOP NOT IN Progress

2. Stoplights ON - Brakes ON - STOP IN Progress

*3. Stoplights OFF - Brakes ON - STOP IN Progress

**4. Stoplights OFF - Brakes OFF - STOP IN Progress

* The message applies in cases where the stoplamps system of the lead vehicle is defective (i.e.: burnt stoplamps).

** The message applies in cases where the lead vehicle operator uses the engine brake (downshifts) to come to a stop or a slowdown. I refer to this message as "The Burnt Stoplights Syndrome."

Note: Operating a vehicle that has its stoplamps system out of order (i.e.: burnt stoplamps) is inconsiderate of other people's safety and is incomsiderate of one's (operator) own safety as well. The same can be said for the operator(s) that downshift to a stop. I address this "The Burnt Stoplamps Syndrome." The use of the device can help keep in check "The Burnt Stoplamps Syndrome." The device restores safety to the operator(s) that uses the downshift method to stop/slowdown his vehicle. The following driver(s) will share same.

7) The device is not to impair the integrity and effectiveness of lighting equipment that the standard requires. The device is to enhance the integrity and effectiveness of lighting equipment that the standard requires.

Downshifting makes use of engine braking energy instead of letting it be wasted. In a world that is energy short, let's make it safe to use that stopping method.

I trust that I have satisfactorily answered your questions. Enclosed is a flow-sheet layout copy of the kit's components and wiring, first version adaptation.

Gustave J. Chicoine, President CSMPCO Corporation ENC.

(Graphics omitted)

WIRING DIAGRAM