Opinion ID: 776872
Heading Depth: 2
Heading Rank: 2

Heading: Jarvis's Sudden Acceleration Theory

Text: 12 Samuel J. Sero, an electrical engineer, testified at trial as an expert for Jarvis. He hypothesized that unintended electrical connections had caused current to run to the cruise control servo, opening the throttle and making the vehicle accelerate. The cruise control servo opens the throttle by means of a vacuum mechanism that has two valves, the vacuum, or vac, valve and the vent valve. The vent and vac valves are controlled by wires attached to the speed amplifier. Victor J. DeClercq, a former Ford design analyst engineer and expert for Ford, agreed that if there was a simultaneous short in the vent and the vac wires, the cruise control servo would open the throttle without the driver pressing the accelerator. 2 The dispute among the experts, however, was whether these kinds of electrical malfunctions could spontaneously occur and, if so, whether a failsafe mechanical device called a dump valve would, despite these malfunctions, disengage the cruise control servo as soon as Jarvis pressed the brake pedal, bringing the sudden acceleration to an end and the vehicle to a stop. DeClercq stated that, to the best of his knowledge, Ford did not test for the fault that Sero suggested as part of its standard failure mode effects analysis of its vehicles. 13 Sero's theory requires two simultaneous malfunctions in the cruise control circuitry. The first is an open ground connection to the speed amplifier, resulting from a loose or broken wire. DeClercq testified that he examined the ground wire in Jarvis's Aerostar after the accident and did not find any evidence that it was cut, was loose, or had shorted out. Sero testified that by the time he examined Jarvis's Aerostar, certain repairs had been made and some parts had been removed from the vehicle for examination, making it difficult to know what condition the wires were in at the time of the accident. The second problem required under Sero's theory is a fault to ground of the vent or the vac wires. 3 According to Sero, an unintended grounding of the vent or the vac wire could occur due to (a) moisture or debris on the circuitry; (b) heat that causes the circuit board to expand or bow up; or (c) a nick in the wire insulation permitting direct contact with metal. There was no physical evidence that any of these events occurred at the time of Jarvis's accident, but Sero described these as random transient events — the first two, at least, could potentially leave no trace. Ford tested the moisture hypothesis by spraying water outside the vehicle and under the hood for one minute and then ran it for fifteen minutes without encountering any problems.