Microsoft Knowledge Base Article 899115 contains the following introduction:
This article discusses how to enable tracing for Microsoft Distributed Transaction Controller (MSDTC) on a computer that is running Microsoft Windows
There are two types of tracing facilities available:
Transaction manager tracing
Transaction manager (TM) tracing tracks transaction state changes and is generated by the MSDTC transaction manager. The transaction manager is part of the MSDTC service process.
Communication manager error tracing
Communication manager (CM) error tracing tracks any process that loads the Msdtcprx.dll file and uses the remote procedure call (RPC) interface of MSDTC to communicate with other MSDTC-related processes.
Note TM tracing and CM error tracing are independent processes. You can enable or disable TM tracing and CM error tracing independently.