Component Inspection

Ignition "OFF".
Ignition "ON" & Engine "OFF".
Connect GDS and select "Diagnostic Trouble Codes (DTCs)" mode.
Using a GDS, Clear DTC.
Check if the pressure sensor's service data shows '0 bar' on the GDS while not pressing the brake pedal.
Check if the pressure sensor's service data rises on the GDS while pressing the brake pedal.
Is the pressure sensor's data unusually shown?
YES
- Substitute with a known-good HECU and check for proper operation.
  If problem is corrected, replace HECU and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.
  NOTE:
  - In a case of replacing HECU, operate following functions
    
    "Steering Angle Sensor Calibration" for steering angle sensor offset correction (refer to C1261 ) - ESC only
    
    "Longituginal Sensor Calibration" for Longituginal sensor offset correction (refer to C1285 ) - ESC only
    
    "Variant Coding" for 2WD/4WD type setting (refer to C1702 )
NO
- This fault is intermittently caused by pressure sensor.
  Go to "VERIFICATION OF VEHICLE REPAIR " procedure.