DTC P0441-9C: Evaporative Emission System Incorrect Purge Flow Low/Insufficient Flow [10/2022 - ]: Description

The description can be found in EVAP (Evaporative Emission) System.

Refer to DESCRIPTION [10/2022 - 11/2023] , or refer to DESCRIPTION [11/2023 - ]

1. Purge Flow Monitor 

   The purge flow monitor consists of the 2 monitors. The 1st monitor is conducted every time and the 2nd monitor is activated if necessary.

   • The 1st monitor

     While the engine is running and the purge VSV (Vacuum Switching Valve) is on (open), the ECM monitors the purge flow by measuring the EVAP pressure change. If negative pressure is not created, the ECM begins the 2nd monitor.

   • The 2nd monitor

     The vent valve is turned on (closed) and the EVAP pressure is then measured. If the variation in the pressure is less than 0.154 kPa (gauge) [0.022 psi (gauge)], the ECM interprets this as the purge VSV or No. 1 check valve being stuck closed, illuminates the MIL and store DTC (2 trip detection logic).

   1. Atmospheric pressure check:
      1. In order to ensure reliable malfunction detection, the variation between the atmospheric pressures, before and after of the purge flow monitor, is measured by the ECM.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *1	Canister	*2	to Intake Manifold
   *3	ECM	*4	Soak Timer
   *5	Purge VSV (On)	*6	Fuel Tank Cap
   *7	Canister Filter	*8	Fuel Tank
   *9	Leak Detection Pump (Off)	*10	Canister Pressure Sensor
   *11	Reference Orifice (0.02 inches)	*12	Vent Valve (Off)
   *13	Canister Pump Module	*14	No. 1 Check Valve
   *15	No. 2 Charcoal Canister Filter	-	-
   *a	EVAP Purge Flow	-	-