What is the operating voltage of an automotive LIN bus?

[LeJeremiah]

LIN bus operates at 12V. The master node is configured with a 1kΩ resistor terminating to 12V power supply, while slave nodes are configured with 30kΩ resistors terminating to 12V power supply. Below is relevant information about LIN bus: 1. Definition: LIN bus is a low-cost serial communication network defined for automotive distributed electronic systems, serving as a complement to other automotive multiplex networks like Controller Area Network (CAN). It is suitable for applications that do not require high bandwidth, performance, or fault tolerance. LIN bus is based on SCI (UART) data format, adopting a single-master/multiple-slave mode, representing a special case of UART. 2. Purpose: LIN aims to provide auxiliary functions for existing automotive networks (e.g., CAN bus), making it a secondary bus network. In applications where CAN bus bandwidth and multifunctionality aren't required - such as communication between smart sensors and braking devices - using LIN bus can significantly reduce costs.

[MacVictoria]

I remember when I used to help people repair cars in the garage, I often tested the voltage issues with LIN bus lines. Generally, the normal working voltage of a car's LIN bus is around 12 volts, which is basically the same as the vehicle's battery voltage, with a normal range between 9 to 18 volts. If you notice a minor function in the car malfunctioning, such as the windshield wipers or door lock buttons not responding, it might be related to the LIN bus. Use a multimeter to measure the voltage at the connection points—if it's below 9 volts, it usually indicates poor grounding or a loose connector, leading to communication failure; if it's above 18 volts, it could be due to a short circuit or an issue with the alternator's output voltage. Once, a car owner complained that the horn wasn’t working, and the LIN voltage measured only 8 volts—it turned out to be due to an oxidized and rusted connector. After cleaning it, everything worked fine again. Although these faults are minor, they can affect driving comfort, so it’s recommended to check the wiring during annual maintenance. Never attempt to fix it yourself, as it could lead to electric shock or damage to the module—always seek a professional technician for safety.

[HenryAnn]

As an average driver, I'm not very familiar with automotive electronics, but I've heard friends mention this thing called LIN bus voltage. It's a circuit used to control small components like power windows or AC switches, normally maintaining a stable voltage around 12 volts. If the voltage gets unstable, those buttons stop responding properly. Once when my window wouldn't open, I checked online and learned it might indicate LIN voltage dropping below 10 volts – sure enough, the repair shop diagnosed it as faulty wiring contact. During normal driving, this voltage fluctuates with battery condition, typically ranging between 9 to 18 volts. Don't underestimate this system – it directly affects driving convenience. I recommend regular maintenance checks for the entire vehicle's electrical system. If any abnormality is detected, stop immediately and call for towing to prevent accidents.

[Philip]

From an electronics hobbyist's perspective, the LIN bus voltage is quite straightforward. It's based on the car battery, nominally 12V DC, but actually fluctuates normally between 9-18V. During signal operation, the high level (idle state) stays close to 12V, while the low level drops near 0V. This can be easily measured with a multimeter or oscilloscope - readings outside this range typically indicate loose grounding or module failure. LIN is commonly used for low-cost sensor control, working alongside complex networks to ensure smooth operation of minor vehicle systems. Don't worry about being too technical - DIY enthusiasts can check voltage points themselves, just remember to use insulated tools to prevent electric shock.