IG "OFF".

IG "ON".

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.

Use the GDS and check that the pressure sensor value rises while pressing the brake pedal.

Is the pressure sensor's data unusually shown ?

	▶ 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.
	▶ This fault is intermittently caused by pressure sensor. Go to "Verification of Vehicle Repair" procedure.