P0441

EVAP CANISTER PURGE VALVE, LOW FLOW





Fault Symptoms
CHECK ENGINE lamp (MIL) on.
Any other diagnostic trouble codes (closed loop system, misfiring)

Conditions.
^ Diagnosis not yet performed this trip.
^ Vehicle speed 0 km/h.
^ Idling.
^ Engine coolant temperature above 60°C.

Diagnostic Help.
The diagnostic trouble code indicates that the flow through the EVAP canister purge valve is too low.
Whether air or fuel is sucked through the valve makes no difference.
Since faults in the EVAP canister purge valve electrical circuit are indicated by a different diagnostic trouble code, fault diagnosis here concerns a mechanical fault. It is important that no hoses are pinched or kinked.

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 in?
YES: Change the valve and 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 coolant temperature exceeds 40°C (104°F) or for at least 1 minute if this temperature is reached earlier.
- Check whether air is sucked into the valve in pulses.

Is the valve pulsing?
YES: Continue with point 3.
NO: Change the valve and continue with point 4.

NOTE: After starting, the purge valve is active for 220 seconds and idle for 130 seconds. Following this, the valve is not active at regular intervals and the time will depend on the control module's fuel adaptation.





3. Check the purge flow from the evaporative emission canister
- Connect the pressure/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 purge flow obtained?
YES: Change the purge valve and continue with point 4.
NO: Repair or replace the hose, change the evaporative emission canister if necessary and continue with point 4.





4. Final check

- Clear the diagnostic trouble code.
- Implementation of driving cycle:
^ Drive the car at varying engine loads and rpm for 5 minutes.
- Evaluation of driving cycle:
^ Check whether the diagnostic trouble code has recurred.

Has the diagnostic trouble code recurred?
YES: Continue at "Before Replacing a Control Module". Component Tests and General Diagnostics
NO: The steps taken to rectify the fault were correct.