WIS Document: 23930

| | P0441 EVAP canister purge valve, low flow Fault symptoms CHECK ENGINE lamp (MIL) on. Conditions P0441 | • | Diagnosis not yet performed this trip. | • | Speed = 0. | • | Idling speed | • | Engine coolant temperature > 60°C. | • | >18 minutes since engine started. Diagnostic help The diagnostic trouble code indicates that a flow exists even though the purge valve is closed. Whether air or fuel vapour is sucked through the valve makes no difference. Diagnosis of the EVAP canister purge valve can be activated with the ISAT scan tool. | - | Select "INITIATE". | - | Select "EVAP". On completion of diagnosis the ISAT scan tool will show "READY", otherwise "NOT READY". The EVAP canister purge valve can be activated by means of the ISAT scan tool. | - | Select "ACTIVATE". | - | Select "EVAP". Check the wiring Intermittent faults may occur as a result of temporary short circuits and breaks in the wiring. Jiggle the wiring at several points and in different directions to ascertain whether the wiring harness, including any connectors, is causing the trouble. Observe the multimeter, ISAT scan tool or test lamp while doing this. Diagnostic procedure 1. Check the air flow | - | Unplug the purge valve's 2- pin connector. | - | Disconnect the hose from the evaporative emission canister side of the valve. | - | Start the engine and, by means of the pressure gauge on the pressure/vacuum pump, check whether air is sucked into the valve. Is air sucked into the valve? | yes Change the valve. Continue with point 4. | no Continue with point 2. 2. Check the valve | - | Switch off the engine and plug in the purge valve's 2-pin connector. | - | Start the engine and run it until the temperature of the coolant exceeds 60°C (140°F), or for at least one minute if this temperature is reached earlier. | - | Check that air is sucked into the valve in pulses. Is the valve pulsing? | yes Continue with point 3. | no Change the valve. Continue with point 5. | Note | The valve is active/inactive at varying intervals. 3. Check the purge flow from the evaporative emission canister | - | Connect the vacuum pump to the hose from the evaporative emission canister. | - | Check whether a steady purge flow is obtained from the evaporative emission canister. Is a steady flow obtained? | yes Change the purge valve. Continue with point 5. | no Repair or replace the hose and also change the evaporative emission canister, if necessary. Continue with point 5. 4. Check the valve's power supply Unplug the connector from the EVAP canister purge valve. | - | Connect the test lamp to: | - | Turn the ignition switch to the ON position. The test lamp should light up. | - | Connect the test lamp to: | - | Start the engine and run it at idling speed. The test lamp should light up or start flashing. | Note | The valve is active/inactive at varying intervals. Test lamp on as above? | yes Change the valve. Continue with point 5. | no Check the wiring connected to the control module for continuity and shorting. Rectify any faults. Continue with point 5. 5. Final check The ISAT scan tool is used to activate diagnosis of the EVAP emission system. For diagnosis to be possible, the following conditions must be fulfilled: | • | Engine running at idling speed. | • | Closed loop active. | • | Vehicle speed = 0 km/h. Perform diagnosis: | - | Connect the ISAT Scan Tool. | - | Clear the fault codes. | - | Select "INITIATE". | - | Select "EVAP DIAGNOSIS". | - | Wait for about 2 minutes or until the ISAT scan tool reads "READY". | - | Obtain a readout of the diagnostic trouble code. Has the diagnostic trouble code recurred? | yes Continue as described in . | no The steps taken to rectify the fault were correct. | Important | Fault diagnosis can be stopped if evaporation of petrol is excessive or if the evaporative emission canister is saturated. To continue diagnosis, proceed as follows: |