DTC Summary

WARNING: This page is about a different car, the 2014 Lexus ES 300h. However, it is still accessible from the selected car via links, so may be relevant.

DTC No.	Monitoring Item	Malfunction Detection Condition	Trouble Area	Detection Timing	Detection Logic
P0441	Purge VSV (Vacuum Switching Valve) stuck open	Leak detection pump creates negative pressure (vacuum) in EVAP system and EVAP system pressure measured. Reference pressure is measured at start and at end of leak check. If stabilized pressure higher than [second reference pressure x 0.2], ECM determines that purge VSV stuck open.	Purge VSV Connector/wire harness (purge VSV - ECM) EGR valve assembly ECM Canister pump module Leak from EVAP system	While power switch off	2 trip
	Purge VSV stuck closed	After EVAP leak check performed, purge VSV turned on (open), and atmospheric air introduced into EVAP system. Reference pressure is measured at start and at end of check. If pressure does not return to near atmospheric pressure, ECM determines that purge VSV stuck closed.	Purge VSV Purge line Connector/wire harness (purge VSV - ECM) EGR valve assembly ECM Canister pump module Canister (filter inside canister clogged) No. 1 canister (filter inside canister clogged) Leak from EVAP system	While power switch off	2 trip
	Purge flow	While engine running, following conditions successively met: Negative pressure not created in EVAP system when purge VSV turned on (open) EVAP system pressure change less than 0.5 kPa(gauge) [3.751 mmHg(gauge)] when vent valve turned on (closed) Atmospheric pressure change before and after purge flow monitor less than 0.1 kPa(gauge) [0.75 mmHg(gauge)]	Purge VSV Purge line Connector/wire harness (purge VSV - ECM) EGR valve assembly ECM Canister pump module Canister (filter inside canister clogged) No. 1 canister (filter inside canister clogged) Leak from EVAP system	While engine running	2 trip