P0441 - EVAP Purge System Performance
| 1 | Filter |
| 2 | ESIM Switch |
| 3 | Evaporative Canister |
| 4 | Fuel Tank Vent (Check Valve) |
| 5 | Control Valve |
| 6 | Inlet Check Valve |
| 7 | Fuel Tank Pressure Sensor |
| 8 | To Purge System |
| 9 | Fuel Fill Tube |
For a complete wiring diagram, refer to appropriate Wiring Diagram.
Theory of Operation
The Evaporative Purge Monitor tests the integrity of the hoses/tube between the throttle body/intake and the fuel tank. The monitor will be enabled under either a Small Leak test or it will run during a Large Leak test (This is when Small Leak test does not pass). During a Small Leak test, the monitor will first evaluate the delta pressure on the Fuel Tank Pressure (FTP) sensor while normal purge control is active. If the monitor does not pass within a calibrated amount of time, then an intrusive monitor will be enabled. This intrusive monitor will ramp in the purge flow to a target amount while evaluating the delta pressure in the entire system. If the delta pressure between purge off and purge on exceeds a calibrated amount, then the monitor will ramp out the purge flow and evaluate the delta pressure between the high flow and the new low flow target. If the delta pressure is less than a calibrated threshold then the monitor will pass.
- >>When Monitored:<< After the Evaporative System small leak test has passed, with the engine running, ambient temperature between 4°C (40°F) and 35° (95°F), with the engine at idle after a calibrated amount of drive time has accumulated.
- >>Set Condition:<< If the Powertrain Control Module (PCM) detects that the purge vapor ratio and the ESIM switch closed ratio are below a calculated value, the PCM commands the purge solenoid to flow at a specified rate to update the purge vapor ratio. If the ratio remains below a specified value, a one trip failure is recorded. Two Trip Fault. Three good trips to turn off the MIL.
| Possible Causes |
|---|
| EVAP PURGE SOLENOID VACUUM SUPPLY |
| EVAPORATIVE PURGE HOSE/TUBE AND FRESH AIR FILTER OBSTRUCTION |
| EVAP PURGE SOLENOID |
| OBSTRUCTED ESIM FRESH AIR FILTER |
| OBSTRUCTED LINE BETWEEN THE FUEL TANK AND CANISTER |
| POWERTRAIN CONTROL MODULE (PCM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .
Test Step 1 - VEHICLE HISTORY AND SERVICE BULLETIN INVESTIGATION
- Ignition on, engine not running.
- With the scan tool, select View DTCs and record the related Freeze Frame data if any DTCs are present.
- Whether or not any DTCs are Active you will want to check the following items which may assist in repairing the customer's complaint successfully:
- Check the vehicle's repair history.
- If the vehicle has a repair history that pertains to the customer's current complaint, review the repair.
- Inspect the vehicle for any aftermarket accessories that may have been installed incorrectly.
- Check for any service bulletin(s) related to the customer's complaint or DTCs.
- If a service bulletin applies, follow the instructions of the service bulletin.
Choose the following scenario that best applies.
The service bulletin repaired the customer's complaint.
- Testing complete.
A DTC is present, no service bulletins apply or the service bulletin didn't repair the customer's complaint.
- Go to Test Step 2
Test Step 2 - ACTIVE DTC
If P0443 is set along with this DTC, perform the diagnostic procedure for P0443 before continuing with this test.
If the customer is experiencing an early fuel shut off during the fuel filling process along with P0440, P0441 and P0452 setting, you need to check for restrictions in the Evaporative Purge tubes/hoses as well as the Fresh Air Filter before continuing.
- Using the scan tool, perform the ESIM FORCED MONITOR TEST. Allow the test to complete.
- With the scan tool, select View DTCs.
If any other DTC sets, active or pending, perform the diagnostic procedure for that DTC before proceeding with this test.
Is the DTC Active or Pending at this time?
Yes
- Go to Test Step 3
No
- Perform the Checking for an Intermittent DTC diagnostic procedure. Refer to CHECKING FOR AN INTERMITTENT DTC .
Test Step 3 - VISUAL INSPECTION
Inspect the Evaporative System for any of the following conditions:
- Holes or cracks
- Loose seal points
- Damaged or missing components
- Incorrect routing of hoses and tubes
- Loose or missing Fuel Cap
- Damaged or missing Fuel Cap seal
- Improper installation of the Fuel Cap
- Damaged Locking tabs on the Fuel Cap and/or filler tube
- Damaged seal points on the Fuel Cap and/or filler tube
Were any problems found?
Yes
- Repair as necessary.
- Perform the Powertrain Verification Test. Refer to PCM VERIFICATION TEST (2009 - 2011) or PCM VERIFICATION TEST (2012 & UP) .
No
- Go to Test Step 4
Test Step 4 - INSUFFICIENT VACUUM SUPPLY TO THE EVAP PURGE SOLENOID
- Turn the ignition off.
- Carefully inspect the EVAP Purge Solenoid vacuum supply hose for proper routing.
- Check for a pinched or plugged hose from the throttle body or intake manifold to the Purge Solenoid.
- Inspect the vacuum port at the throttle body or intake manifold for any damage or obstructions.
Were any problems found?
Yes
- Repair the vacuum supply hose/tube as necessary.
- Perform the Powertrain Verification Test. Refer to PCM VERIFICATION TEST (2009 - 2011) or PCM VERIFICATION TEST (2012 & UP) .
No
- Go to Test Step 5
Test Step 5 - EVAP PURGE HOSE/TUBE AND FRESH AIR FILTER OBSTRUCTION
- Inspect the Evaporative Purge hose/tube for proper routing and installation between the EVAP Purge Solenoid and the Fuel Tank and between the Fuel Tank and the EVAP Purge Canister.
- Make sure the hose/tube and fresh air filter are not damaged, kinked and free from any obstructions.
Were any problems found?
Yes
- Repair or replace as necessary.
- Perform the Powertrain Verification Test. Refer to PCM VERIFICATION TEST (2009 - 2011) or PCM VERIFICATION TEST (2012 & UP) .
No
- Go to Test Step 6
Test Step 6 - EVAP PURGE SOLENOID
After disconnecting the EVAP Purge Solenoid vacuum connections, inspect the lines and solenoid for signs of contamination.
- Using a hand vacuum pump, apply 10 in Hg to the "CAN" side of the EVAP Purge Solenoid.
The solenoid should hold vacuum for a minimum of 15 seconds.
- Ignition on, engine not running.
- With the scan tool, actuate the EVAP Purge Solenoid to the ON position.
The vacuum should drop when the solenoid is actuated.
Does the solenoid function as described above?
Yes
- Go to Test Step 7
No
- Verify that there is good pin to terminal contact in the Solenoid and the Powertrain Control Module connectors. Replace the EVAP Purge Solenoid if no problems were found in the connectors. Refer to REMOVAL AND INSTALLATION .
- Perform the Powertrain Verification Test. Refer to PCM VERIFICATION TEST (2009 - 2011) or PCM VERIFICATION TEST (2012 & UP) .
Test Step 7 - POWERTRAIN CONTROL MODULE (PCM)
- Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the EVAP Purge Solenoid Assembly, ESIM switch and the Powertrain Control Module (PCM).
- Look for any chafed, pierced, pinched or partially broken wires.
- Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the switch, Solenoid and the Powertrain Control Module connectors.
- Perform any Technical Service Bulletins that may apply.
Were there any problems found?
Yes
- Repair as necessary.
- Perform the Powertrain Verification Test. Refer to PCM VERIFICATION TEST (2009 - 2011) or PCM VERIFICATION TEST (2012 & UP) .
No
- Replace and program the Powertrain Control Module. Refer to REMOVAL AND INSTALLATION .
- Perform the Powertrain Verification Test. Refer to PCM VERIFICATION TEST (2009 - 2011) or PCM VERIFICATION TEST (2012 & UP) .