Fault code description for tank pressure sensor, ME-SFI - AD07.61-P-4000-21A

1	Fault code	P0450
2	Fault storage	after the end of the test period and faults
	Activation "CHECK ENGINE" malfunction indicator lamp (MIL)	after two successive driving cycles with faults
3	Frequency of the test	continuous
4	Checked signal or status	A Tank pressure sensor (B4/3), electrical faults B Tank pressure sensor (B4/3), signal oscillates
5	A Fault setting conditions
	upper limit	greater than 4.7 V (corresponds to approx. 35 mbar overpressure)
	lower limit	less than 0.1 V (corresponds to approx. -60 mbar under pressure)
	Test duration	approx. 10 s for each limit
	B Signal curve	The tank pressure with released purge must pulsate by at most 2 mbar (approx. 0.1 V), otherwise the activated charcoal canister may be blocked.
6	Test prerequisites	Idle speed
7		The test is performed independently of the leak test for the purge system. The tank pressure sensor is tested for electrical faults (interruption, short circuit to ground or battery voltage). There is a fault if the sensor voltage goes above or below the limits.
		Characteristic of tank pressure sensor (B4/3): -50 mbar approx. 0.5 V; 0 mbar approx. 3.0 V; +30 mbar approx. 4.5 V.
		The tank pressure sensor may be defective to the extent that the signal is constant and still plausible (sensor sticks). In this case, purge system fault is detected as severe leak.