Data Link Communications Description & Operation: Notes
WARNING: This page is about a different car, the 2004 Saturn L300. However, it is still accessible from the selected car via links, so may be relevant.
Regulations and agreements among the automobile manufacturers have resulted in the Data Link Connector (DLC). This connector must be used for the scan tool and programming access to all communications systems used for those purposes on the vehicle. The connector must have the following:
- A 16-pin connector configuration to which all scan tools connect
- Scan tool battery power always available at pin 16
- Scan tool ground always available at pin 4
- A clean signal ground always available at pin 5
The rest of the pins are available for serial data communications to the vehicle system.
The serial data circuits are the means by which the microprocessor controlled modules in the vehicle communicate with each other and the scan tool. There are 3 different types of protocols on this vehicle:
- Class 2
- Controller area network (CAN)
- Keyword 2000