Opinion ID: 6317316
Heading Depth: 4
Heading Rank: 1

Heading: Evidence of a “Defective Condition”

Text: The TPLA defines “defective condition” as “a condition of a product that renders it unsafe for normal or anticipatable handling and consumption[.]” Tenn. Code Ann. § 29-28-102(2). The district court, focused as it was on the question of causation and traceability, danced around discussing the arguments surrounding a defect. The question on appeal is whether Plaintiffs have established, either by direct or circumstantial evidence, proof that could have led a rational trier of fact to conclude that Parks’ Optima was defective. For four reasons, this Court answers that question in the affirmative. First, the district court summarily declared that Loudon did not provide a defect theory. Our interpretation of the record is different. The results of Loudon’s testing in an exemplar 2008 Kia Optima could lead a rational trier of fact to conclude the design of the vehicle was defective. In that testing, Loudon simulated two acceleration scenarios to determine the cause of the December 31, 2015 accident, querying whether the acceleration was caused by either wide-open throttle (which would presume pedal misapplication) or whether the cruise control subsystem received an incorrect request for the “resume/accel” function on the steering wheel (which would presume some defect in the car). He concluded that the signature on Parks’ instrument panel— about 4,300 revolutions-per-minute (“rpm”) on the tachometer and 92 miles per hour on the speedometer—was most consistent with cruise control application and less consistent with wideopen throttle application.11 A reasonable jury might well choose to believe that the circumstantial 11 At wide-open throttle, the exemplar vehicle’s tachometer indicated rpm between 5,000 and 6,000 and thus did not match the 4,300-rpm reading on Parks’ tachometer. In the second scenario, Loudon simulated where a driver inadvertently presses the “resume-accel” button on the steering wheel, thus allowing the vehicle, through cruise control, to accelerate. In the cruise-control scenario, the exemplar vehicle’s tachometer was 4,119 rpm, so much closer to the signature on Parks’ vehicle. Nos. 20-5690/5693 Hill, et al. v. Kia Motors Am., Inc., et al. Page 17 evidence demonstrates that some defect in the cruise control was more likely than not the cause of the unintended acceleration. Second, the district court employed a cursory review of Kress’ report, only to conclude that he did not offer any defect theory. That is not so. On the contrary, he considered relevant human factors, i.e., that most drivers who accidentally apply the acceleration pedal correct that error within 1.5 seconds, and concluded: “The unintended acceleration behavior of the subject 2008 Kia Optima preceding . . . the collision was not the result of a pedal error or pedal misapplication by Mary Parks.”12 (Kress Report, R. 317-3, PageID # 10149). By ruling out driver error as the cause, the remaining primary inference is that some defect prompted an un-commanded acceleration. Taking Plaintiffs’ argument as true that if Parks accidentally accelerated, then she would have quickly corrected the error and applied the brakes, a jury could reasonably find that some defect in the cruise control caused the acceleration of Parks’ Optima. Third, at the district court, Plaintiffs drew two conclusions from the post-crash vehicle inspections, which showed a half-inch gap between the accelerator pedal and its bracket. The first conclusion is that the accelerator was not pressed to the floor or entrapped in a “floored” manner and that it was completely released if not depressed at all; with regard to the second conclusion, it is also asserted that this gap was consistent with the electrical measurements showing the accelerator pedal in the “idle” position at the time of impact. The district court did not discuss this theory as related to the first prong of the TPLA. 12 What is more, Kress’ report was not solely oriented to retorting the defense theory of pedal misapplication, as the district court stated. Instead, Kress also argued that feasible design alternatives existed that would have addressed the known hazards that can cause unintended acceleration events. This is the subject of the Court’s later discussion. Nos. 20-5690/5693 Hill, et al. v. Kia Motors Am., Inc., et al. Page 18 On appeal, Plaintiffs claim that pedal misapplication can be ruled out if the accelerator pedal was in the idle position, and the possibility of some unspecified cruise control malfunction is rendered more probable. If Parks’ right foot was not on the accelerator pedal at the time of the crash, i.e., the inference Plaintiffs urge, then the defense theory of pedal misapplication is weakened considerably, and Plaintiffs’ rebuttal theory of proper use is strengthened. Thus, the pedal position and the gap could support a finding that something other than driver error caused the accident, thus raising, circumstantially, the possibility of some unspecified cruise control malfunction as the source of the acceleration. Fourth and finally, Plaintiffs contend that reasonable minds could conclude, based on witness and eyewitness testimony, that a sudden acceleration event would not have happened in the absence of a defect.13 This res-ipsa-loquitur-like theory is similar to the Browder-Greco discussion analyzed previously. Some courts call this the “malfunction doctrine” or “malfunction theory.” The malfunction doctrine allows plaintiffs in strict liability cases to infer defectiveness from the negation of other causes. See, e.g., Balducci v. Hyundai Motor Am., Inc., 406 F. App’x 517, 518 (2d Cir. 2011) (“[Plaintiff] offered no evidence demonstrating an ‘absence of other identifiable causes’ [whereas] defendant’s evidence shows that the air bag’s non-deployment was 13 The dissent accuses this opinion of self-contradiction. It states: “In repeatedly and inexplicably claiming that plaintiffs may prove a specific defect with a non-specific defect, the lead opinion shirks the clear requirement under Tennessee law that a specific defect be shown.” (Dissent at 57). This mischaracterizes the opinion. It seems that the dissent incorrectly deems synonymous a “specific defect” and “direct evidence.” However, that a party may make her case out by circumstantial evidence under the TPLA is an unremarkable and irrefutable concept; so, the dissent’s confusion over how a party might plead a case without direct evidence is misplaced. “Where a plaintiff is dependent upon circumstantial evidence [to prove a defect in a product], it is sufficient if he makes out the more probable hypothesis, and the evidence need not []rise to that degree of certainty which would exclude every other reasonable conclusion.” Sigler, 532 F.3d at 486 (Tenn. Ct. App. 1982) (quoting Motley v. Fluid Power of Memphis, Inc., 640 S.W.2d 222, 225). Nos. 20-5690/5693 Hill, et al. v. Kia Motors Am., Inc., et al. Page 19 caused by the low speed of [her] car and the type of crash, not a malfunction[.]”) (quoting another source)).14 Reference to this theory does not relieve Plaintiffs of demonstrating a defect under the TPLA. Plaintiffs do more than solely argue that the facts of the malfunction alone furnish circumstantial evidence of a defect. They point to specific circumstantial evidence and testimony to support this conclusion. Such testimony includes statements from Parks herself, Northcutt, and the eyewitnesses. Parks was known to be a safe and careful driver; Parks’ sister, Northcutt, recalled Parks saying, “Jimmie, there’s something wrong with this car,” and the car would not stop. (See Northcutt Dep., R. 317-19, PageID ## 11603, 11612). When emergency personnel arrived to extract the fatally injured Parks, Parks said, “[she] could not stop.” (Hasty Dep., R. 321- 6, PageID # 12484). Eyewitnesses observed the Kia’s rapid and seemingly uncontrolled acceleration, as well as Parks’ efforts to avoid crashing into others. If Parks was unable to stop or control the vehicle, Plaintiffs’ argument would negate the possibility of causes for which Defendants might not be liable. Viewing the record in the light most favorable to the non-movant, as we must, Plaintiffs have presented proof via circumstantial evidence supporting an inference of a defect, thus meeting the required elements for a triable TPLA cause of action. In summary, then, this Court holds that Plaintiffs have put forth sufficient evidence creating a material factual dispute on the question of a defect under the first half of the TPLA’s first prong. There is a genuine issue of material fact as to whether a defect existed in the Optima. 14 The dissent contends that Plaintiffs never argued such a theory. The record indicated otherwise. That “reasonable minds could conclude, based on the testimony of the witnesses . . . that a sudden acceleration occurred, and that it would not have happened in the absence of some defect” is precisely what Plaintiffs contend. (Pl.’s Br. at 18; see also Pl.’s Mot. in Opposition, R. 325, PageID ## 12729–30) (“[T]here is . . . ample . . . circumstantial evidence that Mrs. Parks’[] event was caused by a malfunction of the cruise control,” including evidence from Kress concluding it “highly unlikely” for an “unintended acceleration event with a duration over 30 seconds and over a half-mile distance to be . . . attributed to driver error or pedal misapplication.”)). Nos. 20-5690/5693 Hill, et al. v. Kia Motors Am., Inc., et al. Page 20 ii. Evidence of an “Unreasonably Dangerous” Condition Pivoting to the latter half of the defect and/or unreasonably dangerous condition prong of the TPLA, Plaintiffs argue that a factual dispute exists as to whether the 2008 Kia Optima and its parts were “unreasonably dangerous,” under Tenn. Code Ann. § 29-28-102(8). “Unreasonably dangerous” means: [A] product is dangerous to an extent beyond that which would be contemplated by the ordinary consumer who purchases it, with the ordinary knowledge common to the community as to its characteristics, or that the product because of its dangerous condition would not be put on the market by a reasonably prudent manufacturer or seller, assuming that the manufacturer or seller knew of its dangerous condition. Id. (emphases added). The statute’s plain language supplies two tests to evaluate if a product is unreasonably dangerous: the consumer-expectation and the prudent-manufacturer tests. The consumerexpectation test applies only to products in which the everyday experience of ordinary consumers can fairly be employed. Ray v. BIC Corp., 925 S.W.2d 527, 531 (Tenn. 1996). Claims involving more complex products are better evaluated under the prudent-manufacturer test in which expert testimony is required.15 Under the prudent-manufacturer test, the buyer’s expectations are irrelevant, and instead, courts ask whether a prudent manufacturer would have placed the product in the stream of commerce. Brown v. Crown Equip. Corp., 181 S.W.3d 268, 282 (Tenn. 2005) (quoting Ray, 925 S.W.2d at 532). The two tests are neither mutually inclusive nor exclusive. Courts often (incorrectly) approach the inquiry as if the tests were diametrically opposed. One reason for this confusion is 15 As a legal matter, expert testimony is only required under the prudent-manufacturer test: “In contrast to the consumer expectation test, [under] the prudent manufacturer. . . . expert testimony about the prudence of the decision to market [the product] would be essential.” Ray, 925 S.W.2d at 531; Sigler, 532 F.3d at 485 (explaining that the prudent manufacturer test “obligate[s]” an injured party “to provide expert testimony”). Nos. 20-5690/5693 Hill, et al. v. Kia Motors Am., Inc., et al. Page 21 that even where the consumer-expectation test might “technically[] apply” in cases involving highly complex products, “it may be difficult for plaintiffs” to prove that product is unreasonably dangerous. Jackson, 60 S.W.3d at 806. The dividing line between the two tests is not always apparent, but the following caselaw marshals us in the right direction: Courts interpreting Tennessee law have used the consumer-expectation test in cases involving seatbelts,16 tires,17 airbags,18 all-terrain vehicles,19 the third-row folding seats in sport utility vehicles and station wagons,20 a hedge trimmer,21 and even where a restaurant failed to disclose its vegan pizza was topped with pecan chips.22 Elsewhere, courts have found that the complexity of other products precludes the use of the consumer-manufacturer test, thereby prompting the application of the 16 Jackson, 60 S.W.3d at 804 (“We are unwilling to accept the defendant’s argument that ordinary consumers cannot form expectations about the safety and performance of seat belts.”). 17 Tatham v. Bridgestone Americas Holding, Inc., 473 S.W.3d 734, 751 (Tenn. 2015) (“We hold that a tire, though vastly different in function, is comparable in its analysis to that of a seat belt.”). 18 Sigler, 532 F.3d at 486 (“Sigler offered evidence that an airbag is such a familiar product and that consumers—and, indeed, manufacturers like Honda—have expectations about the product’s performance and safety.”). 19 Whirley v. Kawasaki Motors Corp., USA, No. 1:04CV1145 T/AN, 2007 WL 9706819, at  (W.D. Tenn. Feb. 21, 2007) (finding that the popularity and prolonged existence of ATVs, and the familiar design—i.e., four wheels, suspension, disc brakes, and a wide wheel base—the average consumer possessed a degree of knowledge and familiarity with the product’s performance). 20 Kines v. Ford Motor Co., No. 119CV01054JDBJAY, 2021 WL 3910323, at  (W.D. Tenn. Aug. 31, 2021) (explaining that such foldable seats “have been marketed in the United States for many years and the ordinary consumer is familiar with the function and characteristics of such features.”). 21 Seaton v. Black & Decker (U.S.), Inc., No. 2:20-CV-124, 2021 WL 1395560, at  (E.D. Tenn. Apr. 13, 2021) (“There is testimony from Defendant’s witnesses that a consumer would know the battery is attached to the hedge trimmer ‘[b]y looking.’”). 22 Jones v. WFM-Wo, Inc., 265 F. Supp. 3d 775, 779 (M.D. Tenn. 2017) (“An ordinary consumer purchasing a slice of vegan pizza may well expect that it would not be topped with pepperoni, sausage or other meats, but the Court cannot say, as a matter of law, that the same consumer would understand that the pizza slice could contain pecan chips.”). Nos. 20-5690/5693 Hill, et al. v. Kia Motors Am., Inc., et al. Page 22 prudent-manufacturer test; these cases have involved industrial forklifts,23 car radiators,24 automotive repair tools,25 medical bronchoscopes,26 steel rod passenger restraints on an amusement park ride,27 a heater,28 and boom-truck cranes.29 It is important to note that in all these cases, the courts found that the consumer-expectation or prudent-manufacturer test applied—not necessarily that the plaintiffs carried their burden thereunder. The district court did not employ any analysis under the “unreasonably dangerous” test, preferring instead to focus on the causation prong of the TPLA. Plaintiffs now argue that a factual dispute exists as to whether Defendants’ 2008 Kia Optima was “unreasonably dangerous” and that material issues of fact exist precluding summary judgment to Defendants under either test. The parties’ arguments under the consumer-expectation test and prudent-manufacturer test are assessed below, in turn. 23 Brown v. Raymond Corp., 432 F.3d 640, 647 (6th Cir. 2005) (noting that an allegation that a forklift was defectively designed is precisely the type of situation in which the ordinary consumer would not have an expectation regarding the safety of a product). 24 Simpson v. O’Reilly Auto. Stores, Inc., No. 2:13-CV-2684-SHL-CGC, 2014 WL 11514969, at  (W.D. Tenn. Dec. 30, 2014) (finding that radiators, while common, are “highly complex and difficult for plaintiffs to establish as dangerous to an extent beyond that which would be contemplated by an ordinary consumer”). 25 Coffey v. Dowley Mfg., Inc., 89 F. App’x 927, 929 (6th Cir. 2003) (“The Super Hub Shark is a complex tool. It is designed to be used for a variety of purposes . . . It is not at all obvious from looking at the tool or even at diagrams showing it in use how it operates, much less how safe it is.”). 26 Young v. Olympus Am., Inc., No. 07-2547-STA, 2012 WL 252645, at  (W.D. Tenn. Jan. 26, 2012) (“Plaintiffs have adduced no evidence that an ordinary consumer would have an expectation about the performance of the bronchoscope at issue.”). 27 Alexander v. Zamperla, No. E200901049COAR3CV, 2010 WL 3385141, at  (Tenn. Ct. App. Aug. 27, 2010) (contrasting plaintiffs’ failure to prove that the safety system deviated from industry standards with defendants’ showing that it complied with industry standards and governing statutes). 28 Brewer v. Mr. Heater, Inc., No. 13-1330, 2014 WL 1364825, at  (W.D. Tenn. Apr. 7, 2014) (reasoning that the prudent-manufacturer test was applicable given the product’s complexity). 29 Johnson v. Manitowoc Boom Trucks, Inc., 406 F. Supp. 2d 852, 858 (M.D. Tenn. 2005) (finding that “the appropriate design of a boom truck crane and the safety features of such a crane are not within the ‘common knowledge of laymen.’”). Nos. 20-5690/5693 Hill, et al. v. Kia Motors Am., Inc., et al. Page 23 Under the “buyer[-]oriented” consumer-expectation test, a product is unreasonably dangerous if it is “dangerous to an extent beyond that which would be contemplated by the ordinary consumer who purchases it, with the ordinary knowledge common to the community as to its characteristics.” Ray, 925 S.W.2d 527 at 530 (internal quotation marks omitted). “[A] product is not unreasonably dangerous if the ordinary consumer would appreciate the condition of the product and the risk of injury.” Id. The test is definitionally inapplicable to products about which an ordinary consumer has no expectation. An ordinary consumer forms an assumption about products that are commonplace, i.e., those products about which the “everyday experience of the product’s users permits a conclusion[.]” Id. at 531 (quoting another source). “The manufacturer or seller’s conduct, knowledge, or intention is irrelevant. What is determinative is what an ordinary purchaser would have expected.” Id. The Tennessee Supreme Court has made clear that “the consumer expectation test does not depend necessarily on a product’s complexity in technology or use.” Jackson, 60 S.W.3d at 806. Instead, the focus is on whether “prolonged use, knowledge, or familiarity of the product’s performance by consumers is sufficient to allow consumers to form reasonable expectations of the product’s safety.” Id. “Even a technically complex failure may involve a subject about which an ordinary consumer may have an expectation, as discussed in Browder.” Coffey, 187 F. Supp. 2d at 972. Here, the question is whether the product at issue is one about which an ordinary consumer could have any expectation. If yes, then the consequent question is substantive: whether Plaintiffs have created an issue of fact that the product was unreasonably dangerous under regular use. We find that ordinary consumers could form expectations about the safety and performance of the cruise control and braking system in the subject 2008 Kia Optima, meaning that the Nos. 20-5690/5693 Hill, et al. v. Kia Motors Am., Inc., et al. Page 24 consumer-expectation test can be applied to the facts presented. Based on the ubiquity of cruise control systems and acceleration and braking pedals in vehicles, their mainstay in everyday life, coupled with the fact that brakes and accelerator pedals are some of the most elemental, required components of cars, the average consumer possesses a degree of knowledge of and familiarity with the product’s performance which not only exceeds that of industrial forklifts and boom truck cranes, see Brown, 432 F. 3d at 647 (explaining an ordinary consumer does not have expectations concerning a forklift); Johnson, 406 F. Supp. 2d at 857 (same, but for boom truck cranes), but is sufficiently developed to form reasonable expectations about vehicular braking and acceleration safety. This case is placed firmly in the long line of caselaw finding the consumer-expectation test applicable to various pieces and parts of passenger vehicles. Sigler, 532 F.3d at 486; Tatham, 473 S.W.3d at 751; Jackson, 60 S.W.3d at 804. One more question in the consumer-expectation test remains. To go forward on a claim that a product is unreasonably dangerous requires the plaintiff to provide sufficient evidence to create a question of fact that the product “[was] dangerous to an extent beyond that which would be contemplated by the ordinary consumer who purchases it[.]” Tenn. Code. Ann. § 29-28-102(8). Plaintiffs argue that the car suddenly accelerated un-commanded and failed to respond to Parks’ application of the brakes; eyewitnesses recalled Parks’ efforts to warn and avoid hitting other motorists, including “flashing” the lights, dodging and warning passersby to get out of the way, and “zigging in and out of these cars,” (Philpot Dep., R. 317-20 at PageID # 11639); and Parks’ repeated statements before and after the crash that she was unable to stop the car and that there was something wrong with the vehicle that commanded its acceleration. In combination, this evidence is enough to get to a jury under the consumer-expectation test. Of the three categories of “ordinary consumers” Plaintiffs identify, i.e., the witnesses to the Nos. 20-5690/5693 Hill, et al. v. Kia Motors Am., Inc., et al. Page 25 accident, Parks herself, and Parks’ sister, Plaintiff Northcutt, Parks’ comments are especially probative. Recall Parks stated that the car “had a mind of its own” and that she attempted to apply the brakes, to no avail. Parks certainly had an expectation that her car would not have accelerated quickly without her intent, and that is enough to establish a consumer’s expectations. Parks’ statements also point to proper handling and weaken the defense retort of pedal misapplication. Accordingly, the district court should have found that the consumer-expectation test applies here; application thereof supplies a genuine issue of material fact of whether the Optima was “unreasonably dangerous” under the TPLA’s consumer-expectation test. Just as under the consumer-expectation test, the district court did not provide any analysis on the prudent-manufacturer test. The prudent-manufacturer test will now be discussed. Liability under the seller-oriented prudent-manufacturer test attaches when a product would not be put on the market by a reasonably prudent manufacturer or seller because of its dangerous condition. The manufacturer is presumed omniscient for purposes of this test, meaning that knowledge of a product’s potentially dangerous condition is imputed. Ray, 925 S.W.2d at 531. Expert testimony about the prudence of the decision to market is essential. Id. Arguing by omission, Plaintiffs declare that the Parks’ 2008 Kia Optima was unreasonably dangerous under the prudent-manufacturer test because of what the manufacturer failed to do (conduct a system-level Failure Modes and Effects Analysis) and what the vehicle was missing (brake throttle override). Plaintiffs attribute this argument to two individuals: one of their remaining experts, Loudon, and Defendant Kia’s corporate representative, Pan Sang Kim, an engineer who designed and developed ECUs. Understanding three engineering concepts—FMEA, ETC, and brake pedal throttle override system—is required to assess Plaintiffs’ argument. Nos. 20-5690/5693 Hill, et al. v. Kia Motors Am., Inc., et al. Page 26 A Failure Modes and Effects Analysis, or “FMEA,” is an engineering process that tests and refines designs to improve reliability. In the automobile context, an FMEA detects and anticipates automotive issues. FMEAs can be limited to a specific component or broadened to assess a product’s design more comprehensively. An electronic throttle control, or “ETC,” is a car’s onboard computer. Imagine a traditional vehicle where a mechanical link—usually, a cable in the carburetor—connects the accelerator pedal and an engine. The ETC cuts out the cord and replaces it with a complex computer system. When a driver of a 2008 Kia Optima presses the accelerator, that command makes its way to the ETC by a single wire. The ETC tells the motor to accelerate and how quickly to do so (or, in engineering terms, the ETC tells the throttle to open and by how much). When a driver of a 2008 Optima presses any of the cruise-control buttons on the steering wheel (i.e., set, resume, accelerate, or cancel), that command flows through that same single wire. A brake throttle override is an engine management software that closes the throttle upon unintended acceleration. The term is otherwise self-explanatory, except for one important detail: override systems bring a car’s engine back to idle only when the brake and accelerator pedal are depressed simultaneously, thereby allowing a driver to stop her vehicle even if the accelerator pedal is stuck. It is unclear whether Parks’ vehicle had a brake throttle override, a question of fact that alone might counsel against summary judgment.30 30 Plaintiffs say that the car did not but argue it could and should have been reprogrammed into the Parks’ 2008 Kia Optima’s ECU at little cost to Kia. Defense expert Walker also appears to doubt Parks’ car had the technology; he writes: “In model year 2008, approximately 70% of all passenger cars and light trucks sold in the U.S., including the 2008 Kia Optima, were not equipped with a brake-throttle override system.” (Walker Report, R. 31715, PageID # 11322). Conversely, Defendants state in their appellate briefing that at least some 2008 Kia Optimas, including the exemplar vehicle Loudon tested, “have a brake override system.” (Defs.’ Br., ECF No. 36 at 33). Nos. 20-5690/5693 Hill, et al. v. Kia Motors Am., Inc., et al. Page 27 With this technical backdrop established, Plaintiffs rely on Loudon and Kim for the contours of their prudent-manufacturer argument. From Loudon, Plaintiffs advance the following: a reasonably prudent manufacturer would not market a vehicle without conducting a system-level FMEA; if Defendant-manufacturer had done so here, it would have concluded that a single signal wire for the cruise control had an unacceptable level of risk. From Kim, Plaintiffs infer that a system-level FMEA was likely never conducted; perhaps even worse still, as Plaintiffs see it, is that Kim testified it was feasible to reprogram and retrofit the electronic control unit (“ECU”) in the Parks’ 2008 Kia Optima with a brake override feature.31 It is claimed that Kim’s testimony demonstrates that the Kia Defendants had actual notice of safety technology that would have prevented the 2015 accident. There is an issue of fact as to whether the design of the car’s control and safety systems was unreasonably dangerous if, as Plaintiffs allege, the manufacturer acted unreasonably in marketing the vehicle with its then-existing design. See Brown, 432 F.3d at 647. Assuming Plaintiffs are correct that Parks’ Optima lacked a brake override feature, Defendants’ failure to retrofit the vehicle with it as an aftermarket feature also counsels against summary judgment under the prudent-manufacturer test. c. Proximate Cause The primary basis on which the district court granted Kia’s motion for summary judgment was that it found no admissible evidence showing how a malfunction in the Optima’s cruise control 31 The transcript of Kim’s deposition is poorly scanned with parts of it unreadable. The bit that is readable indicates that Kim was never provided with or reviewed FMEAs. When asked if KMC “conduct[ed] any sort of feasibility analysis of retroactively reprogramming the ECU in the 2008 Kia Optima 2.4-liter engine in order to put the Smart Pedal feature into those vehicles,” Kim responded: “I can’t say for the entire company whether there was an analysis on the company level[;] I myself did not do an analysis.” (Kim Dep., R. 234-3, PageID # 5458). Kim agreed that he was “[not] familiar with any discussions . . . regarding the retroactive implementation of the Kia Smart Pedal brake throttle override technology.” (Id.). Nos. 20-5690/5693 Hill, et al. v. Kia Motors Am., Inc., et al. Page 28 could have caused unintended acceleration. The district court erred in finding that Plaintiffs have not established a dispute of material fact as to causation. Animating Plaintiffs’ pleadings is a concern that a heightened standard of proof would make it all-but-impossible to establish proximate cause where an electronic defect leaves no trace of a malfunction’s occurrence. It is generally accepted that automobile electronics, unlike some mechanical defects, can fail without a trace, at least as a technical or theoretical matter. See, e.g., Johnson v. Ford Motor Co., No. CV 3:13-6529, 2018 WL 1512377, at  (S.D.W.Va. Mar. 26, 2018) (“[T]here are transient defects which cannot be replicated and leave no trace.”). The possibility of those injured by untraceable electronic vehicular defects being shut out of the courthouse because they are unable to prove causation through direct evidence is obviously undesirable; however, even assuming the existence of a traceless electronic defect, Plaintiffs are not relieved from proving causation at all. See Whaley v. Rheem Mfg. Co., 900 S.W.2d 296, 300 (Tenn. Ct. App. 1995) (“It almost goes without saying that the identified product defect must be the proximate cause of the plaintiff’s injury.”). What varies is the type of proof courts find persuasive. To constitute proximate cause, the cause “must be such that had it not happened[,] the injury would not have been inflicted.” Shouse v. Otis, 448 S.W.2d 673, 676 (1969). “What is meant by proximate cause is not necessarily that which is next or last in time or place, but that which is a procuring, efficient[,] and predominate cause. Closeness in causal relation, rather, is the meaning.” Nash v. Love, 440 S.W.2d 593, 598 (1968) (citation omitted). Circumstantial evidence, like proof of a defect or unreasonably dangerous condition, may be used to rely upon to prove proximate causation. Gable v. Tennessee Liquefied Gas Co., 325 S.W.2d 657, 665 (1957). Nos. 20-5690/5693 Hill, et al. v. Kia Motors Am., Inc., et al. Page 29 In this case, the question is, even if the malfunction (assuming one existed) left no traceable footprint, have Plaintiffs shown that the accident would not have happened if the malfunction had not been triggered. Because the disputed issues of fact are apparent on the trial court record, the district court erred in granting summary judgment in favor of Kia. The path to this conclusion requires discussion of Plaintiffs’ six-fold proximate causation argument. At least four of these arguments (the post-crash pedal position and half-inch gap; eyewitness testimony; Loudon’s exemplar testing; and Kress’ theory of driver correction of pedal misapplication) were the subject of this Court’s earlier analysis. A jury could find each of the six arguments demonstrates that a vehicular defect caused or contributed to the accident. First, the district court found that the post-crash pedal position and half-inch gap between the accelerator pedal and its bracket was not circumstantial evidence that an unspecified cruisecontrol malfunction caused the crash. Below and again on appeal, Plaintiffs assert that the pedal position and the gap indicate that Parks might not have been pressing the accelerator pedal at the time of the crash and that the damage to the pedals was consistent with her right foot being on or off the brake pedal. If so, this weakens the defense suggestion of pedal misapplication, bolstering the possibility of a vehicular malfunction. Summary judgment was not proper because a reasonable jury could infer from the pedal position and the gap that Parks’ foot was not on the accelerator pedal. Second, the district court is correct that the eyewitness testimony does not establish how a cruise control malfunction could cause an unintended acceleration; however, the eyewitness testimony might amount to circumstantial evidence that the vehicle was defective or unreasonably dangerous for ordinary use, leading to an inference of proximate causation. One eyewitness testified as follows: “That’s the only words [Parks] said to me . . . [‘]sir[,] I could not stop.[’]” Nos. 20-5690/5693 Hill, et al. v. Kia Motors Am., Inc., et al. Page 30 (Bill Hasty Dep., R. 321-6, PageID # 12484). Recall Plaintiff Northcutt testified that her sister stated: “Jimmie, there’s something wrong with this car[,]” and that “the car . . . would not stop.” (Northcutt Dep., R. 317-19, PageID ## 11603, 11612). A jury could credit the various eyewitness testimony to conclude that an unspecified malfunction was the source of the sudden acceleration rather than driver error. Third, the district court determined that Loudon’s cruise-control signature testing failed as circumstantial evidence that a non-specific cruise control malfunction caused the crash. The necessary presupposition, the district court said, was missing, i.e., “that an unintended cruisecontrol-induced acceleration is possible.” (Order, R. 341, PageID # 13040). Our reading of the record is different. That an unintended cruise-control-induced acceleration is possible is what Loudon contends. When deposed, Loudon stated: “I understood that primarily my role in [this case] was to determine if a failure of the cruise control system could lead to the circumstances of this accident.” (Loudon Dep., R. 311-2, PageID # 7194). His report also does more than just rely upon Sero’s and Bloch’s excluded testimonies. He proffers independent evidence that his testing of the exemplar vehicle coupled with Parks’ vehicle’s digital footprint indicated “that this accident was much more likely caused by the cruise control system engaging the resume/accel function and accelerating continuously until the vehicle struck another vehicle.” (Loudon Report., R. 317-5, PageID # 10263). A jury could find from Loudon’s report that a faulty component of the cruise control, particularly via the resume/accel button, caused the sudden acceleration here. Fourth, the district court deemed wanting Plaintiffs’ argument, derived from Kress’ humanfactors report, that pedal misapplication is unlikely to persist for the amount of time that the 2008 Kia Optima accelerated. Kress cited literature indicating that a driver recognizes and corrects a pedal misapplication within 1.5 seconds. The district court is correct that this is not direct evidence Nos. 20-5690/5693 Hill, et al. v. Kia Motors Am., Inc., et al. Page 31 of how the cruise control could cause unintended acceleration. But Kress’ report demonstrates circumstantially that most drivers would, almost reflexively, apply the brakes within 1.5 seconds of an accidental acceleration event. Parks’ car accelerated for over thirty seconds at speeds over 90 miles per hour. This circumstantial evidence is sufficient to create a jury question and avoid summary dismissal because a jury could reasonably infer that something other than prolonged pedal misapplication was the source of the acceleration. Fifth, the district court held that Plaintiffs failed to connect the prior occurrences of cruisecontrol Diagnostic Trouble Codes (“DTCs”) in Parks’ vehicle to any prior un-commanded, sudden acceleration. To understand the district court’s holding, some background on DTCs is helpful.32 DTCs are error codes. The Kia Optima can display any five codes, some of which appear on the malfunction indicator lamp (“MIL”) to warn drivers of an issue or malfunction, and some of which do not. DTCs are either “current” or “historical.” A “current” DTC reveals any current issue with a vehicle, and “historical” ones indicate any past issues. When the engine control module (“ECM”) detects a consistent fault in the cruise control switch unit for an established duration, DTC P0564 is triggered. The P0564 error code does not generate a MIL to warn drivers of the issue. In this case, there were no current DTCs registered during Parks’ last seven driving records. But the Kia’s computer system (called the Powertrain Control Unit, or PCU) recorded six historical DTC P0564s in Parks’ vehicle. The “04” refers to a stuck “Resume/Accel” switch. Thus, those six instances of DTC P0564 mean that the cruise control RES/ACCEL button—located on the right side of the steering wheel on the Kia Optima—was stuck or depressed for more than 32 The dissent says “the data [from the National Highway Traffic Safety Administration post-crash investigation report] revealed no ‘trouble codes’ from the car’s onboard computer.” (Dissent at 43). But the dissent fails to consider that the NHTSA downloaded data only from the vehicle’s airbag control unit. (NHTSA Report, R. 204-5, PageID ## 4343–48). In fact, a subsequent data-pull revealed multiple diagnostic trouble codes downloaded from the PCU. Nos. 20-5690/5693 Hill, et al. v. Kia Motors Am., Inc., et al. Page 32 sixty seconds at some point predating the December 2015 accident. Plaintiffs emphasize that P0564 is not triggered unless the stuck condition persists for at least sixty-one seconds; as a result, it is asserted that such an electrical malfunction might have occurred during the 2015 accident that was not registered if the button was stuck for less than sixty-one seconds. Taking Plaintiffs’ allegation as true that a vehicle could accelerate to dangerous speeds before a DTC is detectable, this evidence suggests either a chronically stuck resume/accel switch (which itself might command an acceleration) or otherwise that the historical DTCs show that some electrical malfunction must have occurred in the vehicle. Sixth and finally, the district court found that the depletion of vacuum assist in Parks’ vehicle did not evidence that the cruise control can cause unintended acceleration, let alone the one at issue. We disagree. A depleted vacuum would have made Parks unable to slow the vehicle with the braking pedal due to the wide-open throttle condition. Assuming, as Plaintiffs argue, that Parks attempted to slow the vehicle with the brake pedal during a wide-open throttle condition but was unable to do so due to the depletion of vacuum assist, then, once again, the defense argument of pedal misapplication is undermined. These six theories are circumstantial evidence that an unspecified malfunction caused the crash. We conclude that Plaintiffs have offered sufficient evidence from which a reasonable jury could find that a defective or unreasonably dangerous condition of the Parks’ 2008 Kia Optima proximately caused the accident. Nos. 20-5690/5693 Hill, et al. v. Kia Motors Am., Inc., et al. Page 33 b. Negligence Plaintiffs assert that the district court erred in granting summary judgment on the theory of negligence since there are genuine issues of material fact that create a reasonable inference of Kia’s negligence. For similar reasons explored above, we agree.33 Even though the burden of proof does not shift based on different theories of negligence under the TPLA, Plaintiffs segregate their negligence claim from those of strict liability, done so presumably to couch strict liability as a recovery theory different from negligence. Regardless of which theory of recovery is sought, however, Plaintiffs still must prove that the vehicle suffered from a defect or was unreasonably dangerous, which proximately caused the injuries. Claims of negligence under the TPLA are well steeped in Tennessee law. The general rule is that liability attaches for negligence in the manufacture or sale of a product where the product may be reasonably expected to cause injury by its negligent design or construction. Dunn v. Ralston Purina Co., 38 Tenn. App. 229, 233–34 (1954). Mirroring their prudent-manufacturer argument, Plaintiffs identify four deficiencies appearing to evince Defendants breached a duty to exercise reasonable care: (1) the lack of the brake override; (2) failure to conduct a system-wide FMEA; (3) design defects in the DTC system; and (4) failure to warn. Each argument is, to varying degrees, duplicative of those discussed in the prudent-manufacturer section, and our findings rise and fall with those discussed therein. The 33 Plaintiffs invoke res ipsa loquitur to supply a reasonable inference of negligence. Tennessee, like all states, permits negligence liability under the res ipsa loquitur doctrine. In permitting claims to go to a jury because “the thing speaks for itself,” the TPLA allows a jury to presume negligence where “the accident is such as in the ordinary course of things does not happen if those who have the management use proper care, it affords reasonable evidence, in the absence of explanation by the defendants, that the accident arose from want of [proper] care.” Sullivan v. Crabtree, 258 S.W.2d 782, 784 (1953) (citing another source). Plaintiffs failed to raise res ipsa loquitur in their response to the motion for summary judgment, so they cannot raise it for the first time on appeal, and this argument is not preserved for appellate review. Nos. 20-5690/5693 Hill, et al. v. Kia Motors Am., Inc., et al. Page 34 question is whether a genuine issue of material fact exists as to whether Defendants’ negligence was the proximate cause of Plaintiffs’ injuries. See Leatherwood v. Wadley, 121 S.W.3d 682, 694 (Tenn. Ct. App. 2003). Should it credit Plaintiffs’ evidence, a reasonable jury could find that Defendants’ negligence was the proximate cause of the injuries. First, Plaintiffs contend that despite the feasibility and availability of a brake override system, Defendants negligently failed to install this failsafe system in its 2008 Kia Optima either in the original design or as an aftermarket feature. The district court, finding Plaintiffs’ case failed on causation, omitted any meaningful discussion of the brake-override argument as to negligence. On appeal, Plaintiffs suggest a jury could find that the absence of the brake defect system made the vehicle unsafe for regular use. We agree. Relying upon Loudon, Plaintiffs introduced the following evidence that is sufficient to get to a jury: “If the Parks vehicle had” been equipped with the brake override, “this accident would never have happened.” (Loudon Report, R. 317-5, PageID # 10270). Even if an ordinary consumer does not harbor a precise expectation concerning the initial or retrofitted installation of a brake override system, there certainly would be a consumer expectation that acceleration would stop upon depression of the brakes. Drawing all justifiable inferences in favor of Plaintiffs, this Court finds that a genuine issue dispute of material fact exists as to whether Defendants were negligent in failing to install a brake override system. Second, Plaintiffs, relying upon Loudon, argue that Defendant KMC was negligent in failing to conduct a system-wide FMEA. If it had, Plaintiffs posit the manufacturer would have found the use of a single wire in the cruise control system carried an unacceptable level of risk. This gets to the very core of the case, namely, whether some unidentified defect in the cruise control caused the December 2015 accident. If Plaintiffs’ argument is to be credited—i.e., that Defendants should have, but failed to, conduct a system-wide FMEA, which would have detected Nos. 20-5690/5693 Hill, et al. v. Kia Motors Am., Inc., et al. Page 35 the cruise-control’s susceptibility to command an un-commanded acceleration—then there is a dispute of fact appropriate for jury consideration. Third, Plaintiffs submit a design defect argument related to the DTCs. This argument, drawn primarily from Loudon, requires some patience insofar as it implicates several technical details. The essential point is that Plaintiffs argue that Parks’ 2008 Kia Optima lacked an adequate DTC-detection system that was robust enough to anticipate or respond to unintended acceleration. Plaintiffs say that the design of the 2008 Kia Optima’s cruise control system and its components (including the clock spring coil, the cruise control switch, the single signal wire for cruise control operations, and the interconnects between the switch and the ECM input) were negligently designed. Loudon’s report concluded that an electrical malfunction could have been introduced into Kia’s electronic throttle control system without recording a DTC, meaning that the system does not realize or register that a problem occurred. The consequence, if the premise is to be accepted, would be that an undetected signal could cause the engine’s throttle to open wide without driver input. As a result, it is asserted that Parks’ vehicle should have had a better-designed failsafe mode that ignored errant signals, such as an inadvertently opened throttle. Recall from this Court’s earlier discussion that DTCs related to cruise control can manifest any five codes. Six historical instances of the P0564 were recorded in Parks’ 2008 Kia Optima, indicating a “stuck” cruise control “resume/accel” switch. All that error code means is that the ECM has detected a fault in the cruise control switch, or, in more technical terms, the ECM detected a signal from the cruise control switch that exceeded the threshold value. Distilling Plaintiffs’ arguments from the trial-court level and those on appeal, we deduce a few sub-categories related to the DTC-negligent-design-defect argument. Nos. 20-5690/5693 Hill, et al. v. Kia Motors Am., Inc., et al. Page 36 The first one is temporal, and based on Loudon’s report, that is, the DTCs take too long to be detected, thereby allowing an unintended acceleration event to occur before a trouble code can be spotted by a driver or technician. If Plaintiffs are correct that a vehicle can accelerate to dangerous rates of speed before a DTC is noticed, then a reasonable jury might be able to find that the historical instances of P0564 in the Optima demonstrated the car suffered from some acceleration-related malfunctions. The next sub-argument is a more traditional design-defect argument. Via Loudon, Plaintiffs argue that the use of a single wire in the cruise-control design makes it difficult for the system to distinguish between a legitimate press of a cruise control button and one activated in error. This argument is meritorious and will survive summary dismissal. If the system is unable to distinguish between a stuck “resume/accel” button, an electrical switch signaling problem, or a driver accidentally pressing the cruise control switch, then finding that the system could command an acceleration without driver input is a supported inference. Finally, we turn to the last category in Plaintiffs’ negligence argument. Plaintiffs contend that Kia failed to warn of the dangerous flaw in the Parks’ 2008 Kia that allowed a runaway throttle condition to occur on December 31, 2015. The district court did not assess the failure to warn claim. In Tennessee, a product is not unreasonably dangerous because of a failure to adequately warn of a danger or hazard that is apparent to the ordinary user. Tenn. Code Ann. § 29-28-105(d). For a failure-to-warn claim under the TPLA, “[a]n adequate warning is one calculated to bring home to a reasonably prudent user of the product the nature and the extent of the danger involved in using the product . . . . The adequacy of the warning is a question for the jury unless reasonable minds could agree on the outcome.” Evridge v. Am. Honda Motor Co., 685 S.W.2d 632, 636–37 (Tenn. 1985) (internal quotation marks and citations omitted). The Tennessee Supreme Court held Nos. 20-5690/5693 Hill, et al. v. Kia Motors Am., Inc., et al. Page 37 last year “that the language of the TPLA and accompanying case law places a duty to warn on a manufacturer or seller to warn about the condition of the product only if it was defective or unreasonably dangerous at the time the manufacturer transfers control of the product.” Coffman v. Armstrong Int’l, Inc., 615 S.W.3d 888, 896 (Tenn. 2021). Because we find Plaintiffs demonstrated that the product might have been defective or unreasonably dangerous, the duty to warn is at least implicated. Plaintiffs have also introduced evidence indicating that Defendants knew of feasible design options that would have prevented the accident here. A jury reasonably could find that Defendants were negligent in failing to warn of known defects. Accordingly, we reverse the district court’s grant of summary judgment based on negligence.