DTC U1301: Class 2 Data Link High: Description

Serial data circuit is used to communicate information and commands between modules. In addition, node alive (state of health) messages are transmitted by each module on the serial data circuit about once every 2 seconds. When a module detects no messages and a high voltage on the serial data circuit for about 4 seconds, DTC U1301 is set, the setting of all other class 2 serial communication DTCs is inhibited and the module uses default values for all parameters received on the class 2 serial data circuit.

A current DTC U1301 will clear when a valid class 2 message is detected on serial data circuit or at the end of the current ignition cycle. A history DTC U1301 can only be cleared using scan tool.