The pump motor is a vital component of the BPMV (Brake Pressure Modulator Valve), and the motor relay is an integral part of the EBCM (Electronic Brake Control Module). This relay is not activated while the system is operating normally, but relay operation is required when activating the Anti-lock Braking System (ABS) or Traction Control System (TCS).
When the EBCM grounds the pump motor relay, it closes and battery voltage is sent to the motor, only as long as the valve relay is closed. The control module senses the voltage being applied to the pump motor to check for proper motor performance
If the EBCM detects positive battery voltage when the motor relay is not active, or if the EBCM does not detect positive battery voltage after relay activation, diagnostic code C0110 OBDII will be set.