The EBCM/EBTCM performs system self-diagnostics. The EBCM/EBTCM can detect and often isolate system malfunctions. When a malfunction is detected, the EBCM/EBTCM sets a DTC. The DTC represents the malfunction, turns on the ABS or Traction Control Indicators, and may disable the ABS or TCS functions as necessary for the duration of the ignition cycle.