The use of increasingly sophisticated electrical systems in vehicles has resulted in the need for communication between individual devices and the ECU (control unit) of the car.
In the case of the latest generation of alternators, the controllers use the LIN protocol, which communicates on both sides. This means that the control unit sends a signal to the alternator and the alternator responds to it.
Diagnostics of alternators in our company is carried out on the latest DV Electronics testers, which are able to simulate the signals of the control unit. During the test, the alternator is tested under load, simulating different alternator states.
What is the LIN protocol
The LIN protocol (Local interconnect Network) is a serial communication system used mainly in the automotive industry meeting the ISO-17987 standards. It is a reliable and economical communication protocol that allows the automotive control unit to communicate with individual systems.
There are 2 main LIN groups: LIN1 and LIN2. They differ mainly in the way they communicate and send data. Generally speaking, communication takes place at two speeds: 9600 or 19200 bauds.
Five types (1, 2, 3, 4 and 5) are sent within the LIN protocol, each with 5 different versions (a, b, c, d, and e). These options allow the system to identify, send problems, various information and feedback.
Communication using the LIN protocol is composed of a series of frames representing a specific message. For example: alternator identification and diagnosis.
During communication with the alternator, the control unit can:
- Make and model of alternator
- Make and model of regulator
- Excitation current
Get fault information:
- Controller voltage
- Alternator current
- Response time