What Causes a Car to Fail to Shut Off?
1 Answers
When a car cannot shut off, it is generally due to an electrical circuit malfunction and requires repair at a service station. The specific reason is that the engine control unit (ECU) continues to operate even after the ignition key is turned off, with power being supplied through other circuits. Possible causes include a short circuit to ground or the live wire, or a PCM relay that remains closed due to mechanical reasons. Below is additional information: Introduction: A relay (English name: relay) is an electrical control device that causes a predetermined step change in the controlled quantity in the electrical output circuit when the input quantity changes to meet specified requirements. It establishes an interactive relationship between the control system (also known as the input circuit) and the controlled system (also known as the output circuit). Typically used in automated control circuits, it essentially functions as an "automatic switch" that uses a small current to control the operation of a larger current. In circuits, it plays roles such as automatic regulation, safety protection, and circuit switching. Applications: Relays are automatic switching components with isolation functions, widely used in remote control, telemetry, communication, automatic control, mechatronics, and power electronic equipment, making them one of the most important control components.