The HECU supplies battery power to the electric motor through the motor relay which is controlled by the Electronic Control Unit(ECU). The electric motor pump supplies hydraulic pressure to all wheel brake calipers by operating the piston inside the pump.
The HECU monitors the pump motor circuit and if it is detected as an open/short circuit, fuse open, or motor lock, this DTC is set.
Item
Detecting Condition
Possible Cause
DTC Strategy
Voltage monitoring
Open or short of power supply circuit
Faulty HECU
Threshold value
When the motor pump is activated and the voltage of motor is less than 7.3V for more than 1.8 seconds
When the motor pump is not activated and the voltage of motor is over 0.93V for more than 0.93 second
When a short circuit happens more than three times.
When a short circuit doesn't happen and the mechanical error takes place over ten times.
Fail-Safe
ABS/TCS/ESP funtions are inhibited.
ABS/ESP warning lamps are activated.