DTC U1300: Class 2 Data Link Low: Description

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2002 GMC Savana, 2002 Chevrolet Chevy Express, 2001 GMC Savana Special, 2001 GMC Savana Camper Special, and 2001 GMC Savana. However, it is still accessible from the selected car via links, so may be relevant.

Modules connected to the class 2 serial data line monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged between modules. In addition, node alive (state of health) messages are transmitted by each module on the class 2 serial data line about once every 2 seconds.

When a module detects no messages and a low voltage on the class 2 serial data line for about 3 seconds, DTC U1300 is set, the setting of all other class 2 communication DTCs in inhibited and the module uses default values for all parameters received on the class 2 serial data line. When DTC sets, module inhibits the setting of all other class 2 DTCs and module uses default values for all parameters received on the class 2 serial data circuit. A current DTC U1300 will clear when a valid class 2 message is detected on serial data line or at the end of the current ignition cycle. A history DTC U1300 can only be cleared using scan tool.