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P0441




DTC P0441 EVAP EMISSION CONTROL SYSTEM - INCORRECT PURGE FLOW


Component Location:






GENERAL 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 PCM controls the Purge Control Solenoid Valve (PCSV) to purge any collected vapors from the canister back to the engine for combustion. This valve is actuated by the purge control signal from the PCM and controls fuel vapor flow from the canister to the intake manifold.

DTC DESCRIPTION
During the vapor generation test, the fuel tank pressure sensor value is compared to the value present at the start of the test.The PCM sets DTC P0441 if the pressure signal decrease occurs and the difference is below the predetermined threshold. If the fault is detected within two consecutive test cycles, the PCM illuminates the MIL.


DTC Detecting Condition:






Specification:






Schematic Diagram:









SIGNAL WAVEFORM & DATA
This is waveform measured at terminal 2 of PCSV under no-load, 1500 RPM.
1. The voltage at point 0 is 14 V.
Possible cause:No power supply or open in PCSV.
2. Point (2) is a surge voltage when power TR is off and about 45 V.
3. Period (3) is the duration when PCSV operates and usually operating duty value is about 15 % in 2000 RPM.
4. Period (4) is duty per 1 Hz and ON-OFF ratio of TR in PCM.
During normal operation, the PCSV opens and closes, depending on throttle angle and intake manifold vacuum. when it opens, fuel vapors are flushed from the canister and drawn into the intake manifold. To avoid a vacuum build-up in the canister, the canister close valve is normally held open to allow fresh air to replace the vapors drawn into the intake manifold. The given data is the signal waveform when the PCSV operates normally. Note that the PCSV will not operate until the engine has reached normal operating temperature.

MONITOR DTC STATUS
This is the inspection procedure to determine whether it is present DTC or memoried one by monitoring the current signal or by using the function of oscilloscope with Hi-scan pro.
1. Connect scantool to Data Link Connector(DLC).
2. Warm up the engine to normal operating temperature.





3. Monitor the "EVAP.PURGE VALVE" parameter on the scantool.

NOTE: The data shown above is only for reference and there may be a little difference actually

Service standard
Idle: 0 %
1000 - 3000 rpm:1.5 - 35%

4. Is parameter displayed within specifications?

YES: Fault is intermittent caused by poor contact in the 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 then go to "Verification of Vehicle Repair" procedure.

NO: Go to "W/Harness Inspection" procedure.

ACTUATOR TEST MODE




1. Evap. Leakage Test
Evaporative Emissions Systems (EVAP) Leak Tests can be run by the Scan Tool. The tests are automated and provide either a pass-fail result or directions to check for DTCs.
1. Connect scantool to Data Link Connector(DLC).
2. Warm up the engine to normal operating temperature.
3. Perform "07 EVAP. LEAKAGE TEST " mode
4. Is DTC P0441 set again?

YES: Go to "W/Harness Inspection" procedure

NO: Fault is intermittent caused by poor contact in the sensor's and/or PCM's connector or was repaired and PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection, being, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification vehicle Repair" procedure

TERMINAL & CONNECTOR INSPECTION
1. Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage
3. Has a problem been found?

YES: Repair as necessary and go to "Verification of Vehicle Repair" procedure.

NO: Go to "Power Circuit inspection" procedure.

POWER CIRCUIT INSPECTION
1. Ignition "OFF".
2. Disconnect PCSV sensor connector.
3. Ignition "ON" & Engine "OFF".




4. Measure voltage between terminal 1 of PCSV harness connector and chassis ground.
Specification : approximately B+

5. Is measure voltage within Specification?

YES: Go to "Control circuit inspection" procedure.

NO:
- Open circuit or short circuit to chassis ground between PCSV harness connector and battery power circuit.
- Repair as necessary and then go to "Verification of Vehicle Repair" procedure.

NOTE: In case the voltage at terminal 1 of PCSV is 0 V when PCSV is disconnected.

- Possible cause: Open or short circuit in battery power line after fuse(15 A INJ)

CONTROL CIRCUIT INSPECTION
1. Check for open in harness
1. Ignition "OFF"
2. Disconnect PCSV sensor connector.
3. Ignition "ON" & Engine "OFF"




4. Measure voltage between terminal 2 of PCSV harness connector and chassis ground.
Specification : approximately 3.7 V

5. Is measure voltage within Specification?

YES: Go to "Component Inspection" procedure.

NO:
- Open circuit between PCSV harness connector and PCM harness connector.
- Short circuit to chassis ground between PCSV harness connector and PCM harness Connector
- Repair as necessary and then go to "Verification of Vehicle Repair" Procedure

NOTE: In case the measured voltage is 0 V when checking control line

- Possible cause: If the measured voltage indicates 0 V,the problem is that control line is open, so check the open circuit between terminal 46 of PCM and terminal 2 of PCSV

COMPONENT INSPECTION
The purpose of measuring PCSV resistance is to find if the open circuit is in the component.
1. Check Operation of PCSV
1. Ignition "OFF"
2. Disconnect valve connector and Remove Purge Control Valve.
3. Check that no air flows through valve.




4. Apply 12 V and a ground to 1 and 2 terminals of the Purge Control Valve (To sensor side).
5. Verify that air flows through valve
6. Does Purge Control Valve work properly?

YES: Substitute with a known-good PCM and check for proper operation. If the problem is corrected. replace PCM and then go to "Verification of Vehicle Repair" procedure.

NO: Substitute with a known-good PCSV and check for proper operation. If the problem is corrected, replace PCSV and then go to "Verification of Vehicle Repair" procedure.


NOTE: The purpose of measuring injector resistance is to find if the open circuit is in the component. So, check the continuity between signal line and ground line.

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 rediness test have been verified as "Complete"
5. Are any DTCs present?

YES: Go to the applicable troubleshooting procedure.

NO: System is performing to specification at this time.
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