DTC U1301: Class 2 Data Link High: Description

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 high voltage on the class 2 serial data line for about 3 seconds, DTC U1301 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. A current DTC U1301 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 U1301 can only be cleared using scan tool.