FixVault

P0451 (Noise monitor):

TYPICAL ENABLING CONDITIONS - P0451 (NOISE MONITOR)

Monitor runs whenever these DTCs not present See LIST OF DISABLE A MONITOR 
Atmospheric pressure (absolute pressure) 70 kPa (525 mmHg) or more, less than 110 kPa (825 mmHg)
Battery voltage 10.5 V or more
Intake air temperature 4.4 to 35°C (40 to 95°F)
EVAP pressure sensor malfunction (P0450, P0452, P0453) Not detected
Either of following conditions met A or B
A. Engine Running
B. Time after engine stopped 5 hours

Example of restart time

RESTART TIME

First time 7 hours
Second time 9 hours and 30 minutes