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How Electronic Throttle Control Systems Work

ETC Systems and Outside Signals
Critics allege that power lines and electronic devices can interfere with electronic throttle control.
Critics allege that power lines and electronic devices can interfere with electronic throttle control.

Imagine driving along the route you usually take to work, when your car suddenly starts surging through traffic. It's what some drivers claim has happened to them, and some of them blame the car's electronic throttle control system.

According to some drivers who have experienced unintended acceleration, as well as some experts in automotive engineering, electromagnetic interference can cause electronic throttle control systems to malfunction. In some scenarios, interference from things like cell phones and power lines has been blamed for causing a short circuit in the electronic throttle control, leading to sudden, unintended acceleration.

In the most publicized case, Professor David Gilbert, a professor of engineering at Southern Illinois University, showed on ABC news how he was able to create a short circuit in a Toyota Avalon that caused the engine to rev, accelerating the car without driver input -- and in spite of the application of the brakes [source: Ross].

However, Toyota and other experts fired back that Gilbert's example was contrived and unlikely to occur in the real world. According to Gilbert's critics, he had to cut and reconnect several wires in the system, something that is extremely unlikely to occur in a car that's been used normally [source: Toyota].

While a short circuit could, in theory, cause an electronic throttle control to open the throttle and rev the engine, many experts point out that the systems are well insulated to prevent electromagnetic interference from compromising the system.

However, just because short circuits and interference are unlikely doesn't mean that automakers have ignored the possibility of them happening. Keep reading to learn about failsafes and backups that have been built into electronic throttle control systems.

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