P0441 Evap Purge System Performance

P0441 Evap Purge System Performance - The Powertrain Control Module detects that the rate of change (delta) in fuel tank pressure is below a calibrated threshold during phase 1 (purge solenoid ramped up) or phase 2 (purge solenoid ramped down) of both the non intrusive and intrusive diagnostic.

When monitored this code purge solenoid control circuit DTC is not active, on a cold start condition id the evap system small leak test has passed during the last valid ignition off event. Default actions, MIL is illuminated on the first trip that the diagnostic fails, the MIL will be turned off on the third consecutive trip that the diagnostic phases.

Possible causes:

• Fuel tank pressure (FTP) sensor 5-volt supply open circuit or high resistance.
• Evap purge solenoid vacuum line leaking or broken.
• Evap purge solenoid vacuum line or port restricted/obstructed.
• Pinched/obstructed line between the evap purge solenoid and canister.
• Pinched/obstructed line between the canister and fuel tank.
• Fuel tank pressure sensor.
• Evap purge solenoid.
• Powertrain Control Module (PCM)

Diagnose code P0441 Evap Purge System Performance

Step 1. Check for an active condition

A hot vehicle may conceal a potential leak. For best results, allow the vehicle to cool to ambient temperature before continuing with this procedure. Diagnose and repair a purge solenoid circuit DTC before continuing with this test procedure. Diagnose and repair any 5-volt reference DTC before continuing with this test.

Turn the ignition on. Using the scan tool, read the ESIM switch state and the FTP sensor value.

Do the readings indicate the system is in a vacuum state?

YES, go to step 2.

NO, go to step 3.

Step 2. Check for a blockage between the purge solenoid and the fuel tank

Remove the vacuum line from the outlet port the purge solenoid (this is the line leads to the evaporative canister). Turn the ignition on.

Does the fuel tank pressure sensor change from a negative pressure reading to zero or a positive pressure reading?

YES, go to step 4.

NO, repair the pinched or blocked line between the purge solenoid and the canister or between the canister and the fuel tank.

Step 3. Check for a blockage between the purge solenoid and the fuel tank

Remove the hose at the purge solenoid that leads to the evaporative canister. Attach a hand vacuum pump into the hose leading to the evaporative canister. Turn the ignition on, using the hand vacuum pump, apply vacuum and monitor the fuel tank pressure sensor reading with the scan tool.

Normally, the Fuel Tank Pressure Sensor should read approximately -0.7 psi on the scan tool. The reading should remain stable with no fluctuations. Remove the fuel filter cap (ip equipped) or open the capless fuel filter flap. The Fuel Tank Pressure Sensor should change to approximately 0.5 psi with the Fuel Filler Cap (if equipped) removed or the flap opened on the Capless Fuel Filler assembly. The reading should remain stable with no fluctuations.

Does the fuel tank pressure sensor readings change as described above?

YES, go to step 4.

NO, repair the pinched or blocked line between the purge solenoid and the canister or between the canister and the fuel tank.

Step 4. Check the vacuum supply at the outlet of the purge solenoid

Connect a vacuum gauge to the outlet port of the purge solenoid. Start the engine and check vacuum supply at the purge solenoid outlet port. With the sacn tool, navigate to purge vapors system test, and actuate the purge solenoid to open.

Is vacuum present?

YES, go to step 6.

NO, go to step 5.

Step 5. Check vacuum supply at the inlet of the purge solenoid

Remove the vacuum supply line from the inlet port of the purge solenoid (this is the line that leads to the intake manifold). Connect a vacuum gauge to the vacuum supply line from the intake manifold.

Is vacuum present?

YES, verify that there is good pin to terminal contact in the solenoid and PCM harness connector. Replace the purge solenoid if no problems were found in the conenctors.

NO, repair the cause of loose of vacuum (broken or pinched vacuum supply line or obstruction in the vacuum port).

Step 6. Check the fuel tank pressure (FTP) sensor 5-volt supply circuit for an open/high resistance

Turn the ignition off, disconnect the FTP sensor harness connector. Turn the ignition on, measure the voltage on the FTP sensor 5-volt supply circuit at the FTP sensor harness connector.

Is the voltage between 4.9 to 5.1 volts?

YES, verify that there is good pin to terminal contact in the fuel tank pressure sensor connector. If no problems were found with the connector, replace the fuel tank pressure sensor.

NO, repair the fuel tank pressure sensor 5-volt supply circuit for an open or high resistance.

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