Cruise Controls, Computers and Electromagnetic Interference

Douglas B. Abrams

I. Introduction

The main defense in sudden acceleration cases has been the inability of the Plaintiff to duplicate the incident. This single issue has been the basis upon which many, if not all, Defendants have sought to defeat meritorious claims. Many attorneys who have handled sudden acceleration cases have concluded the answer lies somewhere in the computer chips which were employed in the vehicles. One recent case, in particular, has demonstrated that at least General Motors has recognized the problem of radio interference (RF) or Electromagnetic Interference (EMI) and their effects on the Cruise Control Systems of General Motors vehicles. Another effect of RF may be to set up resonances which cause the cruise control to activate.

Another similar mechanism explaining sudden acceleration is vibrations. This mechanism may be particularly applicable in cruise control systems that use servo systems.

Please note that because of their voluminous nature, I am unable to attach the documents that I reference throughout this paper. However, if you would like copies of any of these documents, please feel free to contact my office.

II. The Search for Answers at the Computer Processor Level

The wide array of instances involving sudden and inadvertent acceleration constitutes powerful evidence that the phenomenon exists. In the case of Stuart v. General Motors, a jury returned a substantial verdict against General Motors in a case involving sudden acceleration. The case was reported as an unpublished opinion by the North Carolina Court of Appeals, however, the transcript of the trial is available. This trial offers some important information into the jury's consideration of evidence related to Sudden Acceleration.

A. Trial Exhibits from Stuart v. General Motors

General Motors itself recognized that radiated electromagnetic interference had the potential for causing the interference with various electric systems. See "Determination of Susceptibility Levels for Automotive Electronic Systems due to Radiated Electromagnetic Interference." This exhibit was offered and received in evidence in the Stuart case. This report asserts: "Electronic Systems may be affected when immersed in an electromagnetic field." Page 1, "Determination of Susceptibility." In similar testing General Motors concluded that conducted or radiated electromagnetic interference could in fact disrupt the proper functioning of the cruise control controller module. See "Controller Module, Request for Test." This exhibit was offered and received in evidence in the Stuart case. This report concluded:

"During radiated Suspectibility samples #4, #5, and #7 could be induced to pull full servo while in cruise mode (brake remained functional and provided escape condition)." See A Controller Module, Request for Test, page 2, dated 10/28/86.

Equally significant is the fact that General Motors found that it could induce a wide open throttle condition with the introduction of bulk current into the system. See "Vehicle Status for U.A. Investigations at EMC," dated May 8, 1987. On May 13, 1987, through the injection of bulk current, General Motors own test revealed that a wide open throttle condition resulted. This Wide Open throttle condition occurred in park, drive, reverse and idle. It was completely unrelated to any driver input because there was no driver involved in the testing. See Page A-5 of the Vehicle Status Report. This event was found to be repeatable. The bulk current was a 1.9-8.5 MHZ. Two days later, a General Motors employee conducting the tests reported: "Found W.O.T. [wide open throttle]. It has been determined that the internal tach is RF susceptible. It will no longer be used." This drew the comment from a supervisor: "WOW." See Page 6, document bates numbered 202241. Similar testing by General Motors revealed similar results. On June 15, 1987, the General Motors testing again revealed that Wide Open Throttle (W.O.T.) was being induced by 1.9 MHZ to 44 MHZ BCI. See Page B-12, document bates numbered 202249. These results were not mentioned in one General Motors summary of these tests, entitled "AC Involvement in Alleged Unintended Acceleration Investigations." According to that author, "AC performs excessive testing of controller to re-evaluate radiated EMC and conducted transient susceptibility No unintended acceleration conditions observed during these tests." See document dated September 22, 1987 and Larry Hocken is named contact person for further unintended acceleration investigation.

Discovery in the Stuart case revealed that General Motors had experienced its own unintended acceleration events with General Motor owned vehicles. On August 22, 1987, at the Willow Run, Michigan General Motors facility, Mr. Jeff Talton crashed into a gate post. See incident report attached to this paper and introduced as evidence in Stuart v. General Motors. Mr. Talton started his 1988 Pontiac Bonneville and put it in reverse. Suddenly the vehicle accelerated into wide open throttle -- despite the fact his foot was on the brake. See incident report introduced as evidence in Stuart v. General Motors. General Motors had an engineer, Mr. Michael Holcomb, examine the vehicle. Mr. Holcomb has testified in a number of cases and it would be interesting to read if he has identified this particular investigation. In another similar set of events, a General Motors Dealership, Arrow Oldsmobile in Milwaukee, Wisconsin reported three separate vehicles in which unintended and sudden acceleration occurred. See Warranty Analysis and Savings Program, dated April 2, 1986. According to the dealership, a salesman was preparing to have a car examined by a potential customer. He put the car in park for approximately four minutes. When he placed the car into drive from the park position, the car accelerated beyond control. In fact, the salesman could not stop the car with both feet stomping on the brake pedal. See Warranty Analysis and Savings Program, dated April 2, 1986. This dealership had a second vehicle experience the same type event. In this instance a service technician started to back out of a parking lot when the vehicle took off. The service technician asserted that he was unable to stop the vehicle even with his foot on the brakes.

This odd scenario repeated itself in an almost identical fashion when a 1986 H-car suddenly accelerated while a salesman was demonstrating the car to a customer. The salesman reported that he felt the pedal pull away from his foot while he put the car into drive. Warranty and Safety Analysis, dated June 26, 1986. A particularly telling statement comes in a handwritten note attached to this report, which states, "VanLandingham regards the "CRUISE" light as indicative of where the failure may be occurring, but I'm not so sure. There may be a path for RF to turn it on." See document bates numbered 202171. In reality, General Motors like all vehicle manufacturers realized long ago that there vehicles were experienced unintended wide open throttle conditions. However, due the transient nature of this dangerous condition, real world duplication of the exact failure is difficult at best. Therefore, the key element for General Motors was to maintain deniability.

Another aspect investigated by General Motors was the effect of vehicle vibration on the cruise control system. On June 29, 1987, General Motors engineers reported on the results of their tests on the effects of vibrations. See Cruise Control Vibrations dated June 29, 1987 attached hereto. This report offered the conclusion that "The cruise control vacuum valve can be opened by vehicle vibration levels experienced under fast idle conditions." See Cruise Control Vibrations dated June 29, 1987 attached hereto. The report further concluded that the "cruise control valve can't be closed by vehicle vibration." See Cruise Control Vibrations dated June 29, 1987 attached hereto. Importantly, these engineers reported that the "cruise control servo vibration is amplified by resonances of its mounting bracket at 28 to 56 MHZ." See Cruise Control Vibrations dated June 29, 1987 attached hereto. On July 27, 1987, in a huge understatement, the author remarks, There was a general agreement that the servo vibration sensitivity was undesirable and steps to reduce or eliminate that sensitivity was discussed. See Joint Meeting on Cruise System, dated July 27, 1987 attached hereto. Engineering Investigations also authored a paper revealing the fault conditions necessary for a vent valve to stick. (1) ignition cycles or cruise switch cycles pulse vacuum valve or (2) vibration at cruise servo can unseat vacuum valve and cause a rapid increase in engine speed.

B. The Use of These Exhibits At Trial

The trial in Stuart v. General Motors had an interesting posture. The driver of the car was a co-defendant. The driver asserted a cross-claim against General Motors. Frank Graham, the defense attorney for the driver, did a marvelous job at trial of showing how absurd it was for General Motors to assert that every unintended acceleration was the result of driver error. In the end, one of the key factors included the factor that General Motors was testing for various types of radiated electronic interference, but nonetheless contended that electronic interference could never affect the cruise control.

III. Chrysler & Sudden Acceleration

A. The Rex Kenney Documents

Mr. Rex Kenney is a engineer in California and was the purchaser of a Chrysler Jeep Cherokee. This vehicle began to suddenly accelerate. Mr. Kenney attempted to have these problems repaired. In a typical stance taken by Chrysler, Mr. Kenney was told that he was simply mistaken and that his Jeep Cherokee would not suddenly accelerate. Unlike many consumers, Mr. Kenney continued to pursue this issue. He made a Freedom of Information Request to the NHTSA and this request yielded some critical documents -- documents which were later contested by Chrysler and apparently removed from the public files. Furthermore, Mr. Kenney carried a videotape camera and recorded some instances of his vehicle's malfunctioning. As Mr. Kenney learned, Chrysler instituted a Task Force to examine unintended acceleration. See Exhibits from Rex Kenney Deposition in Colonna v. Chrysler. The materials obtained by Mr. Kenney are now in the possession of the ATLA Sudden Acceleration Litigation Group. Importantly, Chrysler had previously denied the existence of any such Task Force. See Plaintiff's Reply to Defendant's Response to Plaintiff's Memorandum In Support of Plaintiff's Motion for Sanctions and to Strike Defendant's Expert Testimony in Colonna v. Chrysler. These documents reveal a series of problems with inadvertent acceleration. Finally, much of the documentation in Colonna v. Chrysler was subject to a Protective Order. Additionally, in Sellers v. Chrysler, yet another death resulted from the sudden acceleration of a Jeep Cherokee. See Complaint in Sellers v. Chrysler.

IV. Practical Considerations with Respect to Proving Sudden Acceleration

The existence of Sudden Acceleration can scarcely be argued by the vehicle manufacturers. The Stuart case illustrates the fact that jurors understand that random errors by the internal computers of vehicles are not necessarily capable of being fully duplicated. As a practical matter, some of the most important testimony in these cases are the eye-witnesses to the wreck. For example, a vehicle suddenly accelerating in reverse with a wide open throttle is entirely consistent with a malfunctioning cruise control system. Additionally, the proof of other similar occurrences demonstrates to the jury this event is not a singular and isolated event. Even more productive evidence is likely to come from the testimony of component part suppliers and correspondence between the vehicle manufacturer and the supplier. Additionally, although the manufacturers consistently claim that mere application of a brake would stop the vehicle, drivers have frequently reported being unable to stop the vehicle with the brake pedal mashed to the floor. Thus, eye-witnesses who recall either brake lights or the vehicle continuing to accelerate or maintain a wide open throttle even after the driver has left the vehicle can be critical to the proof of a sudden acceleration case.