What make , model an year vehicle ? U1153 is a communication code . Vehicles with more then one control module have a serial data network for the control modules to talk to each other on .
p0300 is a random misfire which could be low fuel pressure , vacuum leaks etc..
Vehicle doesn't start an run ?
Modules connected to the class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. When a module receives a message for a critical operating parameter, the module records the identification (ID) number of the module which sent the message for state of health monitoring/node alive messages. A critical operating parameter is one which, when not received, requires that the module use a default value for that parameter. Once an ID number is learned by a module, it will monitor for that modules node alive message. Each module on the class 2 serial data circuit is required to send a Node Alive message every 2 seconds. When no message is detected from a learned ID number for 5 seconds,
your best bet , take it to a qualified repair shop .