An electronic control unit (ECU) is tested by an automated D-bus testing tool in a first device. The test tool establishes one or more secure shells between the first device and the ECU. The tool reads test input data from an Excel input file. The ECU comprises a software stack including a test client, a Bluetooth middle layer and a hardware abstraction layer, that communicate internally relative to the ECU, via a D-bus. The test tool sends function calls and parameters via the secure shells to the ECU to test execution of Bluetooth functions and/or Bluetooth profiles. The function calls enable simulation of a human machine interface by the test client. The tool monitors API call returns and logs D-bus communications via the one or more secure shells. The test tool outputs test verdict information and/or D-bus communication logs as text in an Excel file.