Theory Of Operation - Lin Bus
WARNING: This page is about a different car, the 2024 RAM ProMaster EV. However, it is still accessible from the selected car via links, so may be relevant.
The LIN bus is biased through the Commander and Responder (formerly known as Master and Slave) modules. When at rest, the voltage on the LIN network is close to battery voltage. When LIN bus communication occurs, the voltage is pulled low to nearly 0V, creating a digital signal. If a Responder module is disconnected or removed from the network, that module no longer pulls voltage low on the LIN bus, and the average network voltage level will be lower. LIN voltage reads approx. 12V when in sleep mode.
For more information please Refer to COMMUNICATION DIAGNOSIS AND TESTING .