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Diagnostic crime thriller: Trapped in an electric car
This time we are dealing with a case that is both mysterious and spectacular, in which the driver of an ELECTRIC CAR was no longer able to turn off his vehicle. Luckily, his workshop was just open, so a high-voltage technician was able to rescue him from the predicament.
Diagnostic crime thriller: Trapped in an electric car
The case of the car driver, who was practically held hostage by his vehicle, happened around two years ago and has since entertained many a regular gathering of automotive technicians. A high-voltage technician known to the editorial team describes the case, but does not want to name the brand of the electric car. Such a defect could basically occur in all electric vehicles if a few unfavorable factors come together, says our informant. However, this case remains unique so far, which suggests that manufacturers have already learned from it.
It started when the driver of an electric car arrived at his destination, found a parking space and wanted to park his car. But when he wanted to switch off the engine using the start-stop button and took his foot off the brake pedal, the car started again. Even putting the selector lever in neutral didn't help; the automatic transmission remained in the drive position. Only reverse gear could be engaged so that the handlebars could at least maneuver out of the parking space again. Before doing so, he opened the driver's door and unbuckled his seatbelt because, according to the instruction manual, the vehicle's brakes should then lock. To no avail, the car immediately started moving as soon as he released the brake pedal. The driver, trapped in his seat, had no choice but to go to the workshop, which luckily wasn't too far away and was open. When he got there, he called attention to himself by waving and shouting until a technician came to his car and freed it with one hand by pulling out the service plug and thus shutting down the car.
▶ The search for the error was carried out using a special diagnostic device that is networked with the vehicle manufacturer's headquarters. Together, the high-voltage technician on site and the specialist in the manufacturer's maintenance center tracked down the trail.
▶ First it was determined that the so-called crawl mode was switched on, in which the vehicle automatically starts rolling after the brake pedal is released. This crawl mode is preset when the vehicle is started and can be deactivated by the driver at the push of a button, which was not possible in the case described.
▶ After checking the control systems in question, it emerged that the error was in the signal transmission from the selector lever to the engine control unit. The CAN signal for switching gears was disrupted.
▶ The high-voltage technicians exposed the cables responsible for signal transmission and examined them for breaks or other damage. Conclusion: A plug showed traces of moisture and was replaced.
▶ The sensor that was supposed to detect the open door and shut down the engine was also replaced.
▶ The two measures were successful, after which the selector lever worked properly again and the door sensor also reacted as desired. Case solved.
“You could have driven the car slowly into a wall.”A HELPFUL HIGH VOLTAGE TECHNICIAN
PETER SEIPEL DRIVES TO THE WALL
Before the triumph of electronics began, the...Commandsfrom the driver to the machinelinkageas well as Bowden and spring balancerstransmitted. The advantage: If something got stuck, you could immediately sense from the increasing resistance that something was wrong and, if necessary, you could remove the ignition key. Today, only a few vehicles have a key inserted into the lock and the start and stop functionat the push of a button, and also that oneEngine operationis made by invisible peoplecontrol devicesmonitored. No wonder, therefore, that asimple water dropin the wrong place it is enough to put the driver in an at least embarrassing, if not life-threatening, situation.
That was there tooAdvice from the high-voltage technicianIn the case described above, it is only a small consolation that the driver also controls the carslowly against a wallcould have driven.