[Federal Register Volume 86, Number 8 (Wednesday, January 13, 2021)]
[Pages 2733-2739]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-00501]

[[Page 2733]]



National Highway Traffic Safety Administration

[Docket No. NHTSA-2019-0105]

Denial of Motor Vehicle Defect Petition

AGENCY: National Highway Traffic Safety Administration (NHTSA), 
Department of Transportation.

ACTION: Denial of petition for a defect investigation.


SUMMARY: This notice sets forth the reasons for the denial of a 
petition submitted on December 19, 2019, by Mr. Brian Sparks to NHTSA's 
Office of Defects Investigation (ODI). The petition requests that the 
Agency recall Tesla vehicles for an unidentified defect that allegedly 
causes sudden unintended acceleration (SUA). NHTSA opened Defect 
Petition DP20-001 to evaluate the petitioner's request. After reviewing 
the information provided by the petitioner and Tesla regarding the 
alleged defect and the subject complaints, NHTSA has concluded that 
there is insufficient evidence to warrant further action at this time. 
Accordingly, the Agency has denied the petition.

FOR FURTHER INFORMATION CONTACT:  Mr. Ajit Alkondon, Vehicle Defects 
Division--D, Office of Defects Investigation, NHTSA, 1200 New Jersey 
Ave. SE, Washington, DC 20590 (telephone 202-366-3565).


1.0 Introduction

    Interested persons may petition NHTSA requesting that the Agency 
initiate an investigation to determine whether a motor vehicle or item 
of replacement equipment does not comply with an applicable motor 
vehicle safety standard or contains a defect that relates to motor 
vehicle safety. 49 U.S.C. 30162; 49 CFR part 552. Upon receipt of a 
properly filed petition the Agency conducts a technical review of the 
petition, material submitted with the petition, and any additional 
information. 49 U.S.C. 30162(c); 49 CFR 552.6. After considering the 
technical review and taking into account appropriate factors, which may 
include, among others, allocation of Agency resources, Agency 
priorities, and the likelihood of success in litigation that might 
arise from a determination of a noncompliance or a defect related to 
motor vehicle safety, the Agency will grant or deny the petition. 49 
U.S.C. 30162(d); 49 CFR 552.8.

2.0 Petition

2.1 Petition Chronology

    Mr. Brian Sparks (the petitioner) first submitted a valid petition 
conforming to the requirements of 49 CFR 552.4 on December 19, 2019.\1\ 
On December 30, 2019, the petitioner submitted an addendum to his 
petition. This addendum references NHTSA complaint 11291423, which 
alleges unexpected movement of a vehicle that was parked and 

    \1\ The petitioner first raised concerns about SUA in Tesla 
vehicles in September 2019 correspondence with the Agency. NHTSA did 
not consider this earlier correspondence to be a validly submitted 
petition because the petitioner did not provide his name and 
address. See 49 CFR 552.4. The September 2019 letter cited 110 
incidents of alleged SUA in complaints to NHTSA, including 102 
reporting crashes. NHTSA has included the information in 
petitioner's September 2019 correspondence in the Agency's analysis 
of the petition.

    On January 13, 2020, the Office of Defects Investigation (ODI) 
opened Defect Petition DP20-001 to evaluate the petitioner's request 
for a recall of all Tesla Model S, Model X, and Model 3 vehicles 
produced to date based on the information in his correspondence, 
petition and various addendums. On February 21, 2020, the petitioner 
submitted another addendum to his petition, identifying 70 new 
incidents of alleged SUA in NHTSA complaints (also known as Vehicle 
Owner Questionnaires, or VOQs) filed since DP20-001 was opened. 
Additional addendums updating VOQ counts were submitted on April 10, 
2020, June 22, 2020, September 10, 2020 and December 1, 2020. The June 
22 submission included a request to update the petition ``to include a 
recent analysis of Tesla's SUA defect from Dr. Ronald Belt.''

2.2 Petition Basis

    Altogether, the petitioner identified a total of 232 VOQs involving 
unique alleged SUA incidents in his submissions, including 203 
reporting crashes.\2\ The petitioner also submitted a document 
purporting to analyze Event Data Recorder (EDR) data from the incident 
reported in NHTSA VOQ 11216155. The petitioner believes that ``Tesla 
vehicles have a structural flaw which puts their drivers and the public 
at risk'' and bases his request for a recall of the subject vehicles 

    \2\ The petitioner identified a total of 225 VOQ in the original 
petition and five addendums. Six of the VOQs are duplicative of a 
prior VOQ.

    1. His view that, ``The volume of complaints in the NHTSA database 
indicates a severe and systemic malfunction within Tesla vehicles;''
    2. A third-party analysis of data from the crash reported in VOQ 
11206155, which theorizes a fault condition that allegedly ``caused the 
brake pedal to behave like an accelerator pedal;'' and
    3. A complaint (VOQ 11291423) alleging SUA while the driver was 
outside the vehicle, which the petitioner describes as ``the first SUA 
complaint involving a Tesla vehicle in which the driver cannot 
reasonably be accused of pressing the accelerator.''

3.0 Analysis

    ODI performed the following analyses in its evaluation of the 
petition for a grant or deny decision:
    1. Analyzed crashes identified by petitioner for connection to SUA;
    2. Analyzed EDR or Tesla vehicle log data or both from 118 crash 
incidents; \3\

    \3\ This information was not available or not obtained for the 
remaining crash incidents, as detailed below.

    3. Reviewed the crash incident reported in VOQ 11206155;
    4. Reviewed the crash incidents reported in VOQ 11291423;
    5. Reviewed Tesla's system safeguards for the accelerator pedal 
position sensor (APPS) assembly and motor control system;
    6. Reviewed two defect theories referenced in the petition;
    7. Reviewed the brake system designs for the subject vehicles; and
    8. Reviewed service history information for the accelerator pedal 
assemblies, motor control systems, and brake systems for 204 of the 232 
vehicles identified in VOQs submitted by the petitioner.\4\

    \4\ ODI's information request letter for DP20-001 requested 
crash data and service history information for all 124 VOQs cited in 
the original petition and the first two addendums submitted by the 
petitioner. On February 10, 2020 and October 20, 2020, ODI requested 
certain supplemental information for a total of 83 additional VOQs 
alleging crashes, including 80 that were cited in addendums 
submitted by the petitioner.

3.1 Crash Classification

    ODI's crash analysis reviewed 217 incidents, including the 203 
crashes identified by the petitioner and fourteen additional crashes 
reported in VOQs that were either not selected by the petitioner 
(eight) or were submitted after the petitioner's most recent submission 
    Table 1 provides a breakdown of the driving environments and crash 
data review for the crashes analyzed by ODI. Crash data (EDR, Tesla log 
data, and/or video data) were reviewed for 118 of the crash incidents. 
Crash data were not obtained for most of the incidents received after 
DP20-001 was opened.

[[Page 2734]]

                               Table 1--Summary of Crash Incidents Reviewed by ODL
                                                    Crash data      Crash data      Crash data
                    Category                         reviewed      not available   not obtained        Total
Parking lot.....................................              61              44               9             114
Driveway........................................              26              16               4              46
Traffic light...................................              11               7               2              20
Parking garage..................................               7               5               1              12
City traffic....................................               3               1               0               4
Stop-and-go traffic.............................               2               2               0               4
Highway traffic.................................               2               1               1               4
Stop sign.......................................               2               1               0               3
Charging station................................               1               1               1               3
Street side parking.............................               1               1               0               2
Drive thru......................................               1               0               1               2
School drop-off lane............................               1               0               0               1
Car wash........................................               0               1               0               1
Gated exit (China incident).....................               0               1               0               1
    Total.......................................             118              80              19             217

    Six of the crashes reported by the petitioner were assessed by ODI 
as unrelated to SUA. These include all four of the crashes occurring in 
highway traffic, one crash at a traffic light and one of the driveway 
crashes. The highway crashes include two involving loss of lateral 
control due to apparent loss of rear tire grip while driving in the 
rain (VOQs 11297507 and 11307255), one involving late braking for the 
cut-in of a slower moving vehicle (VOQ 11278322), and one for which the 
crash data do not support the allegation and show no evidence of speed 
increase or failure to respond to driver inputs (VOQ 11174732). The 
crash at a traffic light involved unexpected movement of a vehicle 
operating with Traffic Aware Cruise Control enabled after the vehicle 
had come to a stop behind another vehicle at a red light (VOQ 
11307023). The driveway crash incident will be reviewed later in this 
report (VOQ 11291423).
    All of the remaining 211 crashes, assessed by ODI as related to 
SUA, occurred in locations and driving circumstances where braking is 
expected. Eighty-six (86) percent of these crashes occurred in parking 
lots, driveways or other close-quarter ``not-in-traffic'' locations. 
Almost all of these crashes were of short duration, with crashes 
occurring within three seconds of the alleged SUA event.

3.2 SUA Crash Data Analysis

    ODI's analysis of EDR data, log data or both from 118 crashes did 
not identify any evidence of a vehicle-based cause of unintended 
acceleration or ineffective brake system performance in the subject 
vehicles. The data shows that vehicles responded as expected to driver 
accelerator and brake pedal inputs, accelerating when the accelerator 
pedal is applied, slowing when the accelerator pedal is released 
(generally in regenerative braking mode) and slowing more rapidly when 
the brake is applied. ODI did not observe any incidents with vehicle 
accelerations or motor torques that were not associated with 
accelerator pedal applications. In the few cases where the brake and 
accelerator pedal were applied at the same time, the brake override 
logic performed as designed and cut motor torque.
    The data clearly point to pedal misapplication by the driver as the 
cause of SUA in these incidents. Analysis of log data shows that the 
accelerator pedal was applied to 85 percent or greater in 97 percent of 
the SUA crashes reviewed by ODI. Peak accelerator pedal applications 
were initiated within two seconds of the collisions in 97 percent of 
the cases. Analysis of brake data showed no braking in 90 percent of 
SUA crashes and late braking initiated less than one second before 
impact in the remaining 10 percent. The pre-crash event data and driver 
statements indicate that the SUA crashes have resulted from drivers 
mistakenly applying the accelerator pedal when they intended to apply 
the brake pedal. Approximately 51 percent of the crashes occurred in 
the first six months of the driver's use of the incident vehicle.

3.3 VOQ 11206155

3.3.1 Consumer's Description of the Event
    NHTSA complaint 11206155 alleges that a 2018 Tesla Model 3 
experienced an SUA event resulting in a crash in the owner's driveway 
on the evening of May 6, 2019. The complaint states that:
    ``[The driver] turned into [the driver's] driveway and was going to 
pull into [her] garage to park the car, when the car accelerated 
suddenly and violently and crashed into the front stone wall of [the] 
house. The stone wall is damaged and the front right side of the Tesla 
has significant damages.''
    The petitioner referenced the incident reported in VOQ 11206155 in 
the first addendum to the petition,\5\ which included a third-party 
analysis of EDR data from the crash. ODI requested a copy of the EDR 
data in the petition acknowledgement letter. In response, the 
petitioner provided an incomplete copy of the EDR, a copy of a letter 
Tesla sent to the consumer, and a document prepared by the driver that 
provides additional details about the SUA allegation.\6\ The driver 
alleges that the SUA event occurred after the vehicle was ``slowed to a 
halt'' and while the driver was ``waiting for the garage door to fully 

    \5\ Email from Brian Sparks to NHTSA Acting Administrator Owens, 
``Motor Vehicle Defect Petition: Recall Tesla Vehicles Due to Sudden 
Unintended Acceleration,'' December 19, 2019.
    \6\ Email from Brian Sparks to ODI, ``Re_DP20-001 
Acknowledgement Letter,'' February 21, 2020, attachment titled ``My 
Experiences with Tesla Model 3.''

3.3.2 Tesla Letter to the Consumer
    In a July 11, 2019 letter, Tesla provided the consumer with the 
following summary of its analysis of log data for the crash event 
reported in VOQ 11206155: \7\

    \7\ Tesla service manager, letter to the consumer, July 11, 

    ``According to the vehicle's diagnostic log, immediately prior to 
the incident, the accelerator pedal was released, regenerative braking 
was engaged and slowing the vehicle, and the steering wheel was turned 
to the right. Then, while the vehicle was traveling at approximately 5 
miles per hour and the

[[Page 2735]]

steering wheel was turned sharply to the right, the accelerator pedal 
was manually pressed and over about one second, increased from 
approximately 0% to as high as 88%. During this time, the vehicle speed 
appropriately increased in response to the driver's manual accelerator 
pedal input. In the next two seconds, the accelerator pedal was 
released, the brake pedal was manually pressed, which also engaged the 
Anti-Lock Braking System, multiple crash-related alerts and signals 
were triggered, and the vehicle came to a stop.''
3.3.3 ODI Analysis of the Event
    ODI's analysis of the subject crash event included reviews of 
vehicle log data, the EDR report furnished by the petitioner, 
statements from the driver, and a video of the incident provided by 
Tesla. This analysis confirmed the sequence of events described in 
Tesla's letter to the consumer. Figure 1 shows pre-crash vehicle speed 
and driver controls over the ten seconds prior to impact.
    ODI's review of the vehicle log data shows that, approximately 
seven seconds before the crash, the vehicle is completing a right turn 
as the steering angle returns from a large positive value to neutral. 
Over the next second, the driver releases the accelerator pedal and the 
vehicle begins a moderate deceleration under regenerative braking. The 
vehicle begins to turn right toward the owner's driveway approximately 
five seconds before impact. Approximately two seconds before impact, as 
the vehicle nears the apex of the turn into the driveway, the 
accelerator pedal position begins to increase. The accelerator pedal 
increases from 0% to 88% in about one second.

[[Page 2736]]


The accelerator pedal returns to 0% approximately 0.9 seconds before 
impact and the brake pedal is applied approximately 0.5 seconds later. 
The late brake application initiates ABS braking approximately 0.2 
seconds before impact.
3.3.4 ODI Analysis of Event Video File
    An event video file from the vehicle's front camera sensor shows 
the vehicle moving slowly on a residential street before beginning the 
right turn into a short driveway with a moderate positive grade leading 
to twin garage doors separated by a center pillar covered by stonework. 
The vehicle briefly surges forward as it nears the apex of the turn 
into the driveway. The vehicle never stops moving and continues to turn 
right until impacting the center pillar, consistent with the steering 
angle data

[[Page 2737]]

from the log and EDR data. The garage doors remain closed throughout 
the event.
3.3.5 ODI Analysis of EDR Data
    The EDR vehicle speed, accelerator pedal position and steering 
angle data mirror the log data, within the range of expected variation 
due to differences in data resolution, sampling intervals and data 
latencies in the two data recording systems. For example, the vehicle 
speed data reported in the EDR report for the Model 3 has a resolution 
of 1 mph, a sampling frequency of 5 Hz, and a maximum latency of 
approximately 200 milliseconds, while the vehicle speed data recorded 
in the log data has a resolution of 0.05 mph, a logging rate of 1 Hz, 
and a maximum latency of approximately 10 milliseconds.
    The EDR did not record the late brake application and subsequent 
ABS activation. The data log shows that the Restraint Control Module 
(RCM) echoed the brake application in the near deployment alert 
triggered by the impact, indicating that the EDR would be expected to 
show ``On'' for service brake status at impact. Tesla indicated it was 
unable to investigate the apparent discrepancy further without an 
original copy of the EDR report.\8\

    \8\ This is the only event reviewed by ODI in this petition 
evaluation where the data log showed the brake was applied at T0 and 
the EDR did not.

    ODI's reviews of EDR reports for this and several other Model 3 
crash events noted that the polarity of the pre-crash longitudinal 
acceleration data appeared to be reversed in relation to vehicle speed 
data (i.e., negative acceleration displayed when the vehicle speed is 
increasing and positive acceleration displayed when vehicle speed is 
decreasing).\9\ Tesla confirmed that the longitudinal acceleration data 
polarity was reversed in Model 3 EDR reports produced using EDR 
reporting services of v20.2.1 or earlier. Tesla advised ODI that the 
error has been corrected in EDR reporting service update v20.29.1.

    \9\ Acceleration (a) is the change in velocity (v) per unit time 
(t), or a(T) = dv/dt. When vehicle speed is increasing over a given 
time interval, the acceleration is positive in that interval.

3.4 Analysis of Log Data for VOQ 11291423

    VOQ 11291423 alleges multiple incidents of unexpected movement of a 
2015 Model S after parking on an inclined driveway in Lancaster, 
California on December 26, 2019. The complaint states that:
    ``[The] 2015 Model S 85D was reversed onto driveway then placed in 
park and doors were closed and locked. A few moments later the vehicle 
started accelerating forward towards the street and crashed into a 
parked car. Front wheels were receiving power while rear wheels where 
locked and dragging rather than wheels spinning. I reversed vehicle 
back onto driveway and it happened another 2 times after first incident 
within a 30 minute time span.''
    As previously noted, the petitioner's addendum cited this VOQ as an 
``SUA complaint involving a Tesla vehicle in which the driver cannot 
reasonably be accused of pressing the accelerator.'' When interviewed 
by ODI, the owner stated that the vehicle was backed up an inclined 
driveway and parked. The driveway was covered with freshly fallen snow. 
Shortly after he shifted to ``park'' and exited the vehicle, the owner 
observed the vehicle move approximately two car lengths down the 
    The movement stopped when the vehicle reached the level surface of 
the street at the base of the driveway. The owner alleged the movement 
occurred two more times after the vehicle was backed up the driveway 
and parked in a similar position. The second incident involved a minor 
impact with a vehicle parked within a couple of feet of the Tesla, 
resulting in a crack in the front bumper of the second vehicle and no 
damage to the Tesla. The third incident was like the first, with the 
movement ending at the base of the inclined driveway.
    ODI's review of log data from this vehicle found that the movement 
occurred when the vehicle was shutoff with no torque applied to the 
front or rear drive motors. Based on the log data and the physics of 
the vehicle movement from the driveway to the street, it is ODI's 
assessment that the unexpected movement of the parked vehicle was most 
likely caused by insufficient traction of the rear tires on the low-
friction surface of the snow-covered driveway, which resulted in the 
vehicle sliding down the driveway. ODI has excluded this incident from 
its analysis of SUA crashes.

3.5 System Safeguards

    The APPS system used in the subject Tesla vehicles has numerous 
design features to detect, and respond to, single point electrical 
faults, including: Redundant position sensors, contactless inductive 
sensing technology, independent power and ground connections to the 
sensors, and sensor voltage curves that differ by a fixed ratio.\10\ 
All subject vehicles are equipped with accelerator pedal assemblies 
with two independent inductive sensors that convert the angular 
position of the pedal to voltage signals. The pedal position can only 
be changed in response to an external force being applied, such as the 
driver's foot.

    \10\ Second channel output voltage curve is half the slope of 
the first channel.

    The Drive Inverter main processor controls motor torque based on 
accelerator pedal voltage. A separate processor (Pedal Monitor) acts as 
a safety monitor, continually checking both APPS signals for faults and 
independently calculating motor torque. Any malfunction or deviation in 
the APPS system results in a fault mode, cutting torque to zero for 
driver pedal applications or regenerative braking. In addition, the 
Pedal Monitor can shut off the Drive Inverter if driver's commanded 
motor torque and actual motor torque do not match.
    The APPS voltage signals pass through A/D (Analog/Digital) 
converters in the drive unit, which then reports the data to the 
Controller Area Network (CAN) communication bus.\11\ The CAN data are 
time stamped and stored at specified intervals by the data log. The RCM 
receives the data from the drive unit via the CAN bus. The data is 
buffered in the RCM random access memory (RAM) and then written to the 
RCM Electrically Erasable Programmable Read-Only Memory (EEPROM) \12\ 
in the event of a non-deploy or deployment event.

    \11\ The APPS data refresh rate is 10 milliseconds.
    \12\ The EEPROM is a non-volatile memory device that retains 
stored data after cycling power.

3.6 ODI Review of SUA Theories

    As part of its evaluation of DP20-001, ODI reviewed two defect 
theories alleging vehicle-based causes of SUA in the subject vehicles. 
Both theories were developed by Dr. Ronald Belt, the first in 2018 and 
the second in 2020. A paper describing the most recent theory was 
submitted to NHTSA by the petitioner and is based upon Dr. Belt's 
review of EDR data from the crash reported in VOQ 11206155. The other 
theory was referenced by the consumer who submitted VOQ 11206155 and is 
based upon Dr. Belt's third-hand reconstruction of log data from an 
unknown SUA event. Both papers are based upon incorrect event data, 
incorrect reconstructions of event dynamics, and false assumptions 
regarding vehicle design factors.
3.6.1 2020 Theory (VOQ 11206155 SUA Event)
    In an addendum to the petition submitted on June 22, 2020, the 
petitioner requested that NHTSA include a recent paper by Dr. Ronald

[[Page 2738]]

Belt in his petition.\13\ The paper, dated June 1, 2020, claims to 
explain how a ``faulty brake light switch [caused] the brake pedal to 
behave like an accelerator pedal'' in the crash event reported in VOQ 
11206155 that was reviewed earlier in this report (see section 3.3 VOQ 
11206155). The same analysis alleges that the proposed theory ``is 
believed to be the cause of sudden acceleration in over 70% of Tesla 

    \13\ Belt, Ronald. ``Tesla Regen, Brakes and Sudden 
Acceleration.'' Center for Auto Safety, June 1, 2020. https://www.autosafety.org/wp-content/uploads/2015/03/Tesla-Regen-Brakes-and-Sudden-Acceleration.pdf.

    The SUA theory proposed by Dr. Belt in the June 2020 paper appears 
to have originated from his reliance on the pre-crash longitudinal 
acceleration data in the EDR report with the polarity issue recently 
corrected by Tesla (see section 3.3.5 ODI Analysis of EDR Data). Rather 
than recognizing the conflicts between the longitudinal acceleration 
data and other pre-crash data in the EDR report (e.g., vehicle speed, 
rear motor speed and accelerator pedal position all increasing over the 
same time interval as the reported deceleration), Dr. Belt develops his 
reconstruction of the crash event using the inverted longitudinal 
acceleration data and posits a theory to explain how a faulty brake 
light switch can cause the brake pedal to function like an accelerator 
pedal. The theory relies upon numerous assumptions, including: A 
defective brake switch, a large positive torque request from the 
electronic stability control (ESC) system, an alternate explanation for 
the large accelerator pedal position increase shown in the pre-crash 
data, and an alleged veer to the left caused by the presumed ESC 
    ODI does not believe that Dr. Belt's June 2020 paper provides a 
valid theory of an SUA defect in the subject incident or any other 
crash. The theory is based upon inaccurate event data and several false 
assumptions regarding component defects, vehicle dynamics, and motor 
control system design and operation. For example, ODI notes the 
following factual errors and mistaken assumptions contained the subject 
     The vehicle acceleration data used by Dr. Belt in his 
analysis was reported with the polarity reversed. In other words, the 
data shows the vehicle decelerating when it was accelerating and 
accelerating when it was decelerating. As shown in Figure 1, the 
vehicle first accelerates in response to a large accelerator pedal 
application, then decelerates in response to the late brake application 
that triggered ABS braking just prior to impact.\14\

    \14\ ODI estimates that the vehicle was within approximately 
five feet of the stone wall when ABS braking began.

     The evidence shows that the brake light switch functioned 
as designed in the event analyzed by Dr. Belt (see Figure 1).
     The ESC and Traction Control systems cannot request 
positive torque in the subject vehicles.
     The APPS data recorded in the EDR report and data log show 
the physical position of the accelerator pedal (see section 3.5 System 
Safeguards). There is no other source for the accelerator pedal data.
     The vehicle does not veer to the left at any point during 
the crash event (see Figure 1 and section 3.3.4 ODI Analysis of Event 
Video File).
3.6.2 2018 Theory (Unknown SUA Event)
    ODI also reviewed an earlier paper by Dr. Belt suggesting a 
different theory for a vehicle-based cause of SUA in Tesla 
vehicles.\15\ This paper, dated May 1, 2018, was referenced in a 
supplemental submission from the consumer who submitted VOQ 
11206155.\16\ The SUA theory proposed by Dr. Belt in the May 2018 paper 
originated from his reconstruction of accelerator position log data 
from an unknown SUA incident that was described to him over the 
phone.\17\ Based on this reconstruction, Dr. Belt concluded that the 
APPS signal could not have been produced by the driver's application of 
the accelerator pedal, as summarized below from the paper's abstract: 

    \15\ Belt, Ronald. ``Tesla's Sudden Acceleration Log Data--What 
It Shows.'' Center for Auto Safety, May 1, 2018. https://www.autosafety.org/wp-content/uploads/2015/03/Teslas-Sudden-Acceleration-Log-Data-What-It-Shows.pdf.
    \16\ ``My Experiences with Tesla Model 3,'' p 10.
    \17\ The paper provides the following explanation of how the 
accelerator pedal position data was reconstructed: ``In this paper, 
the author has obtained the complete accelerator pedal sensor log 
data for a sudden acceleration incident from a driver who got the 
log data from Tesla during a telephone conversation. The Tesla 
engineer gave a detailed description of the log data to the driver, 
who then provided it to the author. The author then plotted this 
data to create the figure used in this study.''
    \18\ Dr. Belt's reconstruction imagines the APPS log data as a 
square wave, which he asserts could not have been produced by a 
physical application of the accelerator pedal.

    ``Examination of the data shows that the accelerator pedal sensor 
output increased to cause the sudden acceleration. But the increase in 
the accelerator pedal sensor output could not have been caused by the 
driver. Instead, the increase in the accelerator pedal sensor output 
appears to have been caused by a fault in the motor speed sensor, with 
which it shares a common +5V power and ground.''
    Like his June 2020 paper, the theory proposed by Dr. Belt in the 
May 2018 paper is based upon inaccurate event data and false 
assumptions about system design. The APPS data is not recorded in 
Tesla's log data in the manner claimed in the paper (see section 3.3.5 
ODI Analysis of EDR Data).\19\ In addition, circuit design information 
provided to ODI by Tesla shows that Dr. Belt's assumption that ``[t]he 
two accelerator pedal sensors and the motor speed sensor share the same 
+5V regulator and ground,'' is incorrect. Tesla uses two distinct 
regulators with different voltage outputs to supply power to the APPS 
and motor speed sensors. Thus, the May 2018 paper does not provide a 
valid explanation for a fault-based cause of SUA in the subject 
vehicles. Based upon the reported increase in accelerator pedal 
position to 97 percent shortly before collision, the most likely cause 
of the incident described in the May 2018 Belt paper is pedal 
misapplication by the driver.

    \19\ ODI does not believe that Dr. Belt's reconstruction of the 
log data is accurate. The data log is not capable of recording a 
square wave with 1 Hz sampling of the APPS data.

3.7 Brake System

    The subject vehicles are all equipped with pedal-actuated hydraulic 
brake systems that are completely independent of the motor control 
system. No common fault has been identified or postulated that would 
cause simultaneous malfunctions of the brake and motor control systems 
in the subject vehicles. Power assist is provided either electro-
mechanically or from a dedicated vacuum pump. In addition, all subject 
vehicles have Tesla's brake override logic that will cut motor torque 
if the brake and accelerator are applied at the same time. If the 
accelerator pedal is pressed before the brake pedal (or within 100 
milliseconds of brake pedal), motor torque is reduced to zero. If the 
brake pedal is pressed and then the accelerator pedal, motor torque is 
limited to 250 Nm and motor power is limited to 50 kW. In the latter 
condition, the driver should be able to hold the vehicle stationary 
regardless of accelerator pedal position with 85 to 170 N (19 to 38 
lbf) of brake pedal force, depending on the platform.
    Finally, the subject vehicles also contain Tesla's Pedal 
Misapplication Mitigation (PMM) software which uses vehicle sensor data 
to identify potential pedal misapplications and cut motor torque to 
prevent or mitigate SUA

[[Page 2739]]

crashes. ODI's analysis found evidence of PMM activation in 
approximately 13 percent of crashes where log data was reviewed for SUA 
crashes. The effectiveness of the PMM activations have been limited by 
the fact that the original PMM implementation is designed for 
conditions where the vehicle is traveling straight forward or rearward 
toward the collision obstacle. Most SUA crashes reviewed in this 
petition evaluation involved dynamic steering inputs (i.e., vehicles 
with steering angles of 180 degrees or greater when the SUA occurs) 
which the original implementation of PPM was not designed to address.

3.8 Complaint Vehicle Service History Review

    ODI requested service histories for the accelerator pedal 
assemblies, motor control systems and brake systems for 204 of the 
vehicles cited by the petitioner. Only two vehicles had faults 
diagnosed in those components: One motor fault resulting in a vehicle 
stall allegation and the other an APPS fault that appears to have 
resulted from damage incurred by the force of the driver's foot on the 
pedal during the crash event.
    One of the VOQs identified by the petitioner reported feeling a 
jerk forward when approaching a stop sign, then a complete loss of 
power (VOQ 11164094). The data logs from the vehicle show no increase 
in speed and the system cutting motor torque to zero in response to a 
drive inverter fault. ODI does not consider this incident a valid 
example of SUA.
    Another vehicle had an accelerator pedal assembly replaced to 
repair a crash induced fault in one of the pedal tracks (VOQ 11180431). 
The data log shows increased drive motor torque in response to manual 
application of the accelerator pedal to 88.4 percent. After the fault 
in the pedal assembly was detected, motor torque was cut to zero within 
0.04 seconds.
    The service history analysis indicates that component faults are 
not a factor in the SUA incidents reported to NHTSA. The data logs for 
the two incidents that did involve component faults demonstrated that 
system failsafe torque cut logic worked as designed.

5.0 Conclusion

    After reviewing the available data, ODI has not identified evidence 
that would support opening a defect investigation into SUA in the 
subject vehicles. The evidence shows that SUA crashes in the complaints 
cited by the petitioner have been caused by pedal misapplication. There 
is no evidence of any fault in the accelerator pedal assemblies, motor 
control systems, or brake systems that has contributed to any of the 
cited incidents. There is also no evidence of a design factor 
contributing to increased likelihood of pedal misapplication.
    NHTSA is authorized to issue an order requiring notification and 
remedy of a defect if the Agency's investigation shows a defect in 
design, construction, or performance of a motor vehicle that presents 
an unreasonable risk to safety. 49 U.S.C. 30102(a)(9), 30118. Given the 
fact that the event data do not provide evidence that the subject SUA 
was caused by a vehicle-based defect, it is unlikely that an order 
concerning the notification and remedy of a safety-related defect would 
be issued due to any investigation opened upon grant of this petition. 
Therefore, and upon full consideration of the information presented in 
the petition and the potential risks to safety, the petition is denied. 
The denial of this petition does not foreclose the Agency from taking 
further action if warranted or the potential for a future finding that 
a safety-related defect exists based upon additional information the 
Agency may receive.

    Authority:  49 U.S.C. 30162(d); delegations of authority at CFR 
1.95 and 501.8.

Jeffrey Mark Giuseppe,
Associate Administrator for Enforcement.
[FR Doc. 2021-00501 Filed 1-12-21; 8:45 am]