[Federal Register: December 24, 2003 (Volume 68, Number 247)]
[Notices]
[Page 74703-74708]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr24de03-169]
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DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
Denial of Motor Vehicle Defect Petition, DP03-004
AGENCY: National Highway Traffic Safety Administration (NHTSA),
Department of Transportation.
ACTION: Denial of petition for a defect investigation.
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SUMMARY: This notice sets forth the reasons for the denial of a
petition submitted to NHTSA under 49 U.S.C. 30162, requesting that the
agency investigate alleged increased vehicle stopping distance due to
certain failures of the EC-17, Version 2.3 (EC-17), antilock braking
system electronic control unit (ABS ECU) and the Dura Drain M-12
modulator (M-12), both manufactured by Bendix Commercial Vehicle
Systems, LLC (Bendix). The petition is identified as DP03-004.
FOR FURTHER INFORMATION CONTACT: Mr. Jonathan White, Office of Defects
Investigation (ODI), NHTSA, 400 Seventh Street, SW., Washington, DC
20590. Telephone: (202) 366-5226.
SUPPLEMENTARY INFORMATION: In June 2003, Mr. Jing Tang (Petitioner)
filed a petition for a defect investigation alleging that potential
safety defects existed in both the EC-17, Version 2.3 (EC-17), antilock
braking system electronic control unit (ABS ECU) and the Dura Drain M-
12 modulator (M-12), both manufactured by Bendix Commercial Vehicle
Systems, LLC (Bendix). The Petitioner asserted that the defects in both
components resulted in extended vehicle stopping distances. Both
components are used in the pneumatic antilock braking systems of
commercial type vehicles. The EC-17 is an electronic controller for the
antilock braking system of large trucks, truck tractors and buses,
while the M-12 is a modulator and relay valve combination used on large
trailers. The Petitioner, a former staff control engineer with the
Bendix Braking Control Group, cited his personal familiarity with the
components as the basis for his allegations.
The Petitioner contacted ODI in September 2002 to convey his
concerns regarding these components. During the intervening months,
prior to the submission of his petition, ODI monitored its consumer
complaint database and attempted to follow up with possible
complainants.
After receiving the petition for a defect investigation, ODI
reviewed and analyzed data and information from multiple sources that
included material provided by the Petitioner, vehicle owner complaints
contained within the NHTSA consumer complaint database, and information
provided by Bendix in response to an ODI inquiry.
EC-17 ECU Issue
Background
In July 2000, Bendix initiated a recall (NHTSA 00E-041) of
the EC-17 1030R ECU primarily because the unit's software was unable to
differentiate false incoming signals. The controller's interpretation
of the signals activated the antilock feature, which extended braking
distances under certain conditions. The EC-17 1030R was manufactured
between November 3, 1997 and August 16, 2000.
At the time NHTSA was notified of the recall decision, Bendix
reported that they had conducted an investigation and identified the
underlying issues that prompted the action. The Bendix investigation
concluded that the EC-17 1030R controller was receiving ``false''
signals through the wheel speed sensor input. The controller was then
interpreting these false signals as impending wheel lock-up. In
response to the impending wheel lock-up interpretation, the controller
would command the reduction of pneumatic pressure to the vehicle brake
chamber at the affected wheel. Under such conditions, with the braking
system antilock feature now activated, the vehicle could experience an
extended stopping distance.
Bendix identified two potential sources of the false wheel speed
signals. The first source was identified as chafing to the wheel speed
sensor wire due to contact with other moving or rotating components.
The other source of aberrant signals was identified as damaged or
displaced wheel components, such as tone rings.
Bendix concluded that by itself, the EC-17 1030R controller was not
defective, but in the presence of false or aberrant wheel speed
signals, the controller lacked the sufficient software codes to
differentiate these signals from otherwise valid signals. Beginning
mid-June 2000, Bendix introduced the EC-17 Version 2.3,\1\ which
contained software that adequately addressed the issue of wheel speed
signal differentiation. The EC-17 Version 2.3 controller was introduced
to replace the recalled EC-17 1030R controllers. In addition, Bendix
introduced the EC-30 in mid-2001 to supercede the EC-17 series. As the
EC-30 controller was introduced, it
[[Page 74704]]
was also used as a remedy part for the EC-17 1030R recall.
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\1\ Production of 210,913 units between 06/13/00 and 09/25/01.
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The Petitioner alleges that the algorithm used in the EC-17 Version
2.3 only corrected for potential low speed (less than 12 MPH) braking
problems on rough road surfaces. His concern is that extended vehicle
braking distances could otherwise occur at higher speeds on rough
surfaces. To illustrate his concern, the Petitioner referenced a
``hardware-in-loop simulation'' that depicted an extended vehicle
braking distance on a washboard-type surface. During the simulation,
the Petitioner reported that there was no air ``pressure in the brake
chamber for the first 15 seconds.'' The Petitioner also referenced a
Kansas City area customer who complained of ``non-effective brakes''
when the vehicle was operated on a rough surface as a possible example
of such an occurrence.
Bendix Response
Subsequent to the recall, Bendix continued to monitor complaints of
extended vehicle braking distances and identified the potential for
extended vehicle stopping distances on unpaved and ``severely bumpy''
road surfaces, such as those occasionally found in rural areas. The
company's analysis, which included individual contact with
complainants, revealed that an extended braking distance event was only
likely to occur on severely rough road surfaces that extended for more
than 100 feet. During field-testing, Bendix was unable to reproduce an
extended braking event on a typical ``washboard'' \2\ surface.
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\2\ Bendix advised ODI that there is not an industry
``benchmark'' for the evaluation of rough road or ``washboard''
performance.
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Regarding the Petitioner's allegation that extended braking
distances could occur at high speeds on washboard surfaces, Bendix
reported that such occurrences have not materialized in field testing
or through owner complaints. Bendix advised that the Petitioner's
allegations are based upon computer simulations ``involving
artificially induced electronic inputs'' that ``are more extreme even
than worst case scenarios.'' According to Bendix, although ``many of
these signals are not realistic or real world conditions,'' they are
often bench-tested with an ECU \3\ to assist engineers with evaluating
possible algorithm changes. Bendix concludes that although the
Petitioner cites potential scenarios of extended braking distances, the
basis for his conclusions involve conditions not applicable to ``real
world'' conditions.
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\3\ Defined as ``hardware in loop'' simulation.
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Regarding the Petitioner's allegation that a Kansas City-area
complaint concerned extended vehicle braking distances on rough road
surfaces, Bendix noted that at the time of the complaint, the remedy
for the EC-17 1030R recall had not been performed on several vehicles
from the fleet in question. Bendix reported satisfactory resolution of
the complaint upon completion of the recall remedy and, for two of the
vehicles, the correction of foundation brake problems.
Bendix reasserted that potential events of extended braking
distances are only likely to occur on severe rough roads where the
``washboard'' surface extends more than 100 feet. The company concludes
that such conditions are atypical highway conditions and that the
potential can be mitigated through driver intervention. Bendix stated
that investigation of the few complaints of extended braking distances
revealed that the vehicles were being operated on unpaved surfaces and
that by assuring increased driver awareness of ABS operation the
complaints or concerns were resolved.
In consideration of these ``extreme conditions,'' Bendix introduced
the EC-30 ABS controller in June 2001. The company reports that the EC-
30 Version 2.02 ``provides improved performance on extreme washboard
surfaces.'' In sum, Bendix asserts that there is no safety defect with
the EC-17 Version 2.3 controller.
Bendix reported no knowledge of any crashes or injuries
attributable to poor performance of either EC-17 version. Although
Bendix did acknowledge the occurrence of a property damage collision
\4\ wherein an ABS-equipped bus rear ended another bus, separate
investigations by law enforcement, the local school system, and Bendix
all concluded that the sole cause was unrelated to the brake system
operation and was attributed to driver inattention.
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\4\ March 2002, West Virginia--paved, straight, level, dry road
surface at a controlled intersection.
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Bendix Complaint and Warranty History
ODI queried Bendix with regard to complaints and warranty claims
that referenced the EC-17 controller, excluding those that referenced
the model 1030R that was recalled. Bendix reported that it has received
18 complaints (including reports of incidents or inquiries) regarding
poor performance, including extended braking distances (complaint rate
equals to 8.5 per 100,000 units). Of the 18 complaints, only four
specifically mentioned performance issues related to the vehicle being
operated on a rough or ``washboard'' surface (corrected complaint rate
1.8 per 100,000 units). Within these complaints, where the surface
condition was known, it was described as unpaved. Of the remaining 14
complaints, five were conclusively identified as unrelated to the ABS
ECU. The nine remaining complaints were resolved through other
component repairs or by providing additional information to the
complainant (presumably the complainant used the information to resolve
the complaint).
Bendix identified a total of 10th \5\ warranty claims related to
the EC-17 ABS control unit between September 2000 and January 2003.\6\
Although the basis for the warranty claims are not identified, at least
two claims were identified as involving the 1030R model in
circumstances where the recall remedy had not been installed.
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\5\ Corrected warranty rate is 3.7 per 100,000 units.
\6\ As of June 2003.
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ODI Actions
ODI research of the NHTSA vehicle owner (or consumer) complaint
database revealed no complaints regarding malfunction, failure, or
extended vehicle braking distance with regard to a Bendix brand
pneumatic antilock braking system component.
ODI also communicated informally with International and Blue Bird
(two manufacturers that participated in the 1030R recall) and was
advised that these manufacturers had not received any new complaints
after the recall remedy was performed.
M-12 Modulator Issue
Background
The Petitioner alleges that his review and work on the modulator
revealed that it could become ineffective at maintaining pneumatic
brake pressure under cold ambient temperatures (less than 20-degrees
Fahrenheit). The Petitioner stated that his research revealed that
under cold ambient temperatures, the rubber diaphragm in the modulator
could become rigid, thereby not permitting it to effectively seal the
pilot chamber drain hole during a brake application. Should the drain
not seal, sufficient pneumatic pressure may not be delivered to the
brake chamber. The Petitioner reported that ``an internal test''
confirmed his suspicion of the diaphragm becoming rigid at cold
temperatures.
M-12 Modulator and Relay Valve Assembly
Bendix describes the M-12 as a combination modulator and relay
valve
[[Page 74705]]
assembly \7\ for the pneumatic antilock brake system on large trailers.
Information provided by Bendix indicates that the M-12 was manufactured
between November 1997 and March 2001 with a total production of
approximately 78,509 units. Additional information indicates that the
M-12 underwent four modifications during the years of production. Those
modifications are summarized in the table below.
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\7\ The M-12 also carries the designation of MC-12 when an ECU
is combined with the modulator/relay valve assembly.
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Date Modification
------------------------------------------------------------------------
March 1998................................ Change in solenoid supplier.
August 1998............................... Dura Drain Feature Added.
September 1999............................ Housing Casting Improved.
October 2000.............................. Dura Drain Feature
Discontinued.
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With regard to the defect petition, the most applicable
modification would appear to be the introduction of the Dura Drain
feature, which was added as a product improvement. Bendix reported an
approximate production of 50,778 units (approximately 64% of the total
units) with this feature. The Dura Drain feature was subsequently
discontinued, reportedly as a means to reduce cost. Production of the
M-12/MC-12 was discontinued approximately 5 months later (March 2001),
as it was replaced by the MC-30 modulator/ECU assembly.
M-12--Bendix Response
Bendix advised ODI that with regard to the defect alleged by the
Petitioner, the company conducted an investigation that consisted of
multiple tests and studies. This investigation began in November 2000
after a Bendix representative, while on a routine customer contact
visit, was informed of an issue that was described as ``inconsistent
trailer braking.'' The customer, a vehicle fleet owner with facilities
near the Bendix headquarters, regularly participated in the evaluation
of Bendix products. According to Bendix, the complaint concerned
reports of three fleet drivers who described an occurrence of ``trailer
push,'' in which the vehicle driver senses that the trailer brakes
appear to operate more slowly or less effectively than the tractor
brakes. The ensuing investigation determined that the likely cause was
a diminished build up of air pressure in the trailer brake system.
During the early stages of the investigation, the Petitioner's
allegation and analysis that diaphragm rigidity due to cold ambient
temperatures was considered as a possible cause. Bendix reported that
further evaluation and testing ``cast doubt'' on the Petitioner's
contentions. The company reported that there had been no similar
complaints during the winter months of 1998, 1999 and early 2000.
Furthermore, the compound used in the M-12 diaphragm was specified for
adequate performance to -40 degrees Fahrenheit. Bendix reported that
testing at cold ambient temperatures could not ``consistently replicate
the predicted (poor) performance'' due to a rigid diaphragm.\8\
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\8\ Data provided by Bendix does indicate that some early
testing revealed occasional leakage of Dura Drain at colder
temperatures when the antilock system is active. Additionally,
Bendix concedes that a rigid diaphragm could lead to degradation in
antilock brake performance.
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Nonetheless, Bendix continued to receive trailer-braking
complaints, many outside of winter months. As Bendix conducted detailed
inspections of the M-12 modulators, the company observed ``a strong
correlation (of braking complaints) to the presence of solid or fibrous
contamination in the air intake valve area.'' The company also observed
that the complaints ``were regionally clustered'' and ``specific to
certain vehicle (trailer) makes.'' The conclusion of their
investigation was that contamination in the intake port of the valve
and not the rigidity of the diaphragm was the most likely cause for a
majority of the ``trailer push'' or extended braking distance
complaints. Bendix also noted that an evaluation of some complaints
revealed other causes such as kinked air lines or external valve
damage. Regarding the source of the contamination, Bendix cited the
observation of material consistent with insect infiltration or
hibernation as well as possible maintenance practices.
Bendix reported no known occurrences of crashes or injuries
associated with the lack of performance or failure of the M-12
modulator.
Bendix Complaint and Warranty History
ODI queried Bendix with regard to complaints and warranty claims
that referenced the M-12. Bendix provided ODI with data indicating that
between April 1999 and early August 2003, the company received
complaints on 139 M-12 units \9\ that were in use on trailers owned by
seven (7) fleets. Nearly 70% of the complaints were received from one
large fleet described by Bendix as one that regularly participates in
product evaluations. A second large fleet accounted for approximately
18% of the complaints, revealing that nearly 88% of the complaints
originated with two fleet operations.
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\9\ Complaints appear to reflect all M-12 units. There was no
differentiation between units produced with and without the Dura
Drain feature, resulting in an overall complaint rate of 17.7 per
10,000 units.
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Bendix reported that in those cases in which it was able to
investigate the basis for the complaint, contamination of the air
system was identified in approximately 94% of the complaints. With
regard to the contamination, Bendix reported that the majority
consisted of evidence of insect nesting and fibrous/cloth material
likely to have been introduced during vehicle assembly or maintenance.
For all but 27 complaints, Bendix provided information on the month
and year of the complaint (identified as the date of occurrence).
Review of the data revealed that more than half of the complaints were
received during 2001. The data also revealed that less than one half of
the complaints occurred during the winter months of November through
February. These trends are illustrated in the tables below.
BILLING CODE 4910-59-P
[[Page 74706]]
[GRAPHIC] [TIFF OMITTED] TN23DE03.000
Bendix reported processing 65 warranty claims \10\ between October
1999 and June 2003. Review of the data indicates that less than one
half of the warranty claims were processed during the winter months of
November through February. Information provided with the warranty
claims offered few analytical details regarding the reason for the
warranty claim. It is also noteworthy that the product descriptions for
warranty claims reference both the M-12 (9.5% of the claims) and the
MC-12 (90.5% of the claims). Since the MC-12 also contains the ECU,
some of the claims may be related to components other than the Dura
Drain feature. The warranty data provided no differentiation between
units equipped or not equipped with the Dura Drain feature. Warranty
trends are illustrated in the tables below.
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\10\ Warranty rate of 8 per 10,000 units.
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[[Page 74707]]
[GRAPHIC] [TIFF OMITTED] TN23DE03.001
BILLING CODE 4910-59-C
ODI Actions
Review of the NHTSA vehicle owner complaint database revealed no
complaints regarding the M-12 modulator or extended trailer stopping
distances. ODI staff did contact one of the vehicle fleet owners
identified by the Petitioner. The fleet representative advised ODI that
although Bendix evaluated the performance of their trailers, driver
training appeared to be the greater problem. The fleet had no
continuing concerns.
Conclusion
ODI acknowledges the Petitioner's personal involvement in the
evaluation of the performance of both the EC-17 Version 2.3 ABS
controller and the M-12 modulator assembly. Although the Petitioner
offers information that is not entirely disputed by Bendix, his
contention that the components contain defects that relate to motor
vehicle safety is not supported by the available data.
With regard to the EC-17 Version 2.3 ABS controller, data provided
by Bendix revealed that extended braking distances were only likely on
extremely rough surfaces (over long distances) characteristic of
unpaved surfaces. Although the company's next generation ECU reportedly
improves performance in this type of setting, Bendix reported that
enhanced vehicle driver awareness has mitigated the issue for the EC-
17. ODI has no independent information that contradicts this assertion.
With regard to the M-12 modulator, data provided by Bendix revealed
that although diaphragm rigidity (due to cold ambient temperatures) may
degrade antilock performance (i.e., extend braking distance during an
ABS event), the company's investigation and analysis failed to
consistently replicate the poor performance. Furthermore, Bendix
provided data that showed a greater number of complaints and warranty
claims occurring during warmer weather. Their analysis also identified
the presence of air system contamination in an overwhelming number of
complaints.
[[Page 74708]]
Upon review of the available data it is unlikely that NHTSA would
issue an order requiring the notification and remedy of a safety-
related defect in either the EC-17 Version 2.3 or the M-12 modulator at
the conclusion of an investigation. Therefore, in view of the need to
allocate and prioritize NHTSA's limited resources to best accomplish
the agency's safety mission, the petition is denied.
Authority: 49 U.S.C. 30162(d); delegations of authority at CFR
1.50 and 501.8.
Issued on: December 18, 2003.
Kenneth N. Weinstein,
Associate Administrator for Enforcement.
[FR Doc. 03-31753 Filed 12-23-03; 8:45 am]
BILLING CODE 4910-59-P