About eight years ago, I was riding with friends in a car when it suddenly stopped running. We were able to coast to the side of the road, and after the driver switched the car off and restarted it, everything worked normally again. Around the same time, the traffic lights and a nearby school lost power, suggesting that the small town was experiencing a blackout. Could the town's power failure somehow have affected the car's computer, or was the timing most likely just a coincidence? The car's manufacturer had no connection to the town.
3 Answers
Cars contain several separate computers. If the engine-control system actually failed, the engine could shut off, while a restart might reset the fault. However, the town’s outage would not normally cause that. A failing battery, alternator, loose connection, or voltage spike inside the car is a much more plausible explanation.
A normal blackout would not directly shut down a car, since the car’s electronics are powered by its battery and alternator rather than the town power grid. An electromagnetic pulse or solar storm is extremely unlikely, because it would generally affect many vehicles and electronic devices over a wider area. The car may simply have experienced a temporary electrical or computer fault that cleared when it was restarted.
It depends on what ‘the computer stopped working’ means. If it was only the radio, navigation, or connected services, the blackout could have affected nearby communications equipment or cellular infrastructure. If the engine stopped, though, the timing was probably coincidental or both events may have been caused by a local electrical disturbance. There is no need to invoke a secret EMP test.
The car did stop moving, but it had enough momentum for us to coast over. Restarting it brought the radio and other controls back, so it may have been a temporary fault rather than anything related to the blackout.