P0441
DTC P0441 EVAP. EMISSION SYSTEM INCORRECT PURGE FLOWGENERAL DESCRIPTION
The evaporative emission control system prevents hydrocarbon (HC) vapors from the fuel tank from escaping into the atmosphere where they could form photochemical smog. Gasoline vapors are collected in the charcoal canister. The evaporative canister is designed to trap and store fuel vapor emissions from the fuel tank.
When the carbon in the canister is unsaturated, fuel vapor passing over and through the activated carbon surface is absorbed and fresh air can pass out through the vent system with very little residual fuel vapor. When fresh air is drawn through the canister from the vent system, fuel vapors recombine with the air and are metered into the engine.
DTC DESCRIPTION
This test detects a leak across the purge valve by measuring an increase in evaporative system vacuum. A leak across the purge valve can allow hydrocarbons from the tank to leak to the atmosphere when the engine is off. The test should be calibrated to detect a 0.02 inches (0.5mm) leak path across the purge valve. This test does not require idle conditions to run. Checking output signals from tank vacuum under detecting condition, if signals is high than threshold for more than 2 sec., PCM sets P0441. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till 1 driving cycle.
DTC Detecting Condition:
Schematic Diagram:
MONITOR SCANTOOL DATA
1. Warm-up engine to normal operating temperature.
NOTE: Evaporative Emissions Systems (EVAP) Leak Tests can be run by the Scan Tool. The tests are automated and provide either a pass4ail result or directions to check for DTCs.
2. Install scan tool and clear DTC
3. Perform "EVAP. LEAKAGE TEST" mode referring to enable conditions as below
4. Monitoring for (pending) DTC by performing DIAGNOSTIC TROUBLE CODES" or "MONITORING TEST RESULTS". Is the same DTC set?
YES: Go to "Component Inspection" procedure.
NO: Fault is intermittent caused by poor contact in sensor's and/or PCM's connector or was repaired and PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection,bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of vehicle Repair" procedure.
COMPONENT INSPECTION
1. Check PCSV
1. Ignition "OFF"
2. Remove PCSV and check it for open stuck or leak
3. Measure resistance between terminals "1" and "2" of the PCSV connector.
Specification: Approx.24.5 - 27.5 ohms (20 degrees C(68 degrees F))
4. Connect Scantool and Perform ACTUATION TEST for PCSV with Scantool
5. Check that clicking sound can be heard by actuation test.
6. Monitor the PCSV signal waveform and verify that the ground voltage is less than approx. 0.3 V (1) and the surge voltage (2. is between 40 V and 60 V.
7. Is the PCSV normal?
YES: Substitute with a known - good PCM and check for proper operation.
If the problem is corrected, replace PCM and go to "Verification of Vehicle Repair" procedure.
NOTE: There is a memory reset function on Scantool that can erase optional parts automatically detected and memorized by PCM After testing PCM on the vehicle, use this function to reuse the PCM on the others
NO: Substitute with a known good PCSV and check for proper operation.
If the problem is corrected, replace PCSV and go to "Verification of Vehicle Repair" procedure.
VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Monitor and record the Freeze Frame Data for the Diagnostic Trouble Code(DTC) which has been diagnosed.
2. Using a Scantool, Clear the DTCs
3. Operate the vehicle within conditions noted in the freeze frame data or enable conditions
4. Monitor that all readiness tests have been verified as" Complete"
5. Are any DTCs present?
YES: Go to the applicable trouble shooting procedure.
NO: System is performing to specification at this time.