P0441

P0441-EVAP PURGE SYSTEM PERFORMANCE

Special Tools:










For a complete wiring diagram, refer to the Wiring Information.

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 is a two stage test and runs only after the Evaporative system passes the small leak test. Stage one is non-intrusive. The Powertrain Control Module (PCM) monitors the purge vapor ratio and the Evaporative System Integrity Monitor (ESIM) Switch closed ratio. If the purge vapor ratio is above a calculated value, the monitor passes. If the ESIM switch closed ratio is greater than calculated value when purge flow is greater than a minimum value, the monitor passes. Stage two is an intrusive test and runs only if stage one does not pass. The PCM commands the purge solenoid to flow at a specified rate to force the purge vapor ratio to update. The ratio is compared to a calibrated specification. If it is less than specified, a one trip failure is recorded. This test can detect if the purge hose is off, obstructed or the purge valve is not operational.

- When Monitored:
After the Evaporative System small leak test has passed, with the engine running, ambient temperature between 4° C (39° 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.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. VEHICLE HISTORY AND SERVICE BULLETIN INVESTIGATION
1. Ignition on, engine not running.
2. With the scan tool, select View DTCs. Record the Freeze Frame data if any DTCs are present.
3. 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 per the service bulletin.

Choose the following scenario that 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 2

2. ACTIVE DTC

NOTE: Allow the vehicle to reach ambient temperature before continuing with this procedure.

NOTE: If P0443 is set along with this DTC, perform the diagnostic procedure for P0443 before continuing with this test.

NOTE: 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.

1. Start the engine.
2. Allow the engine to idle.
3. Using the scan tool, perform the ESIM FORCED MONITOR TEST. Allow the test to complete.
4. With the scan tool, select View DTCs.

NOTE: 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 3

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.

3. VISUAL INSPECTION
1. Turn the ignition off.
2. Perform a visual and physical inspection of the entire Evaporative Emission system.
3. Check for the following conditions:
- Improper installation of the Fuel Fill Cap
- Holes or cracks
- Loose seal points
- Evidence of damaged components
- Incorrect routing of hoses and tubes
- Loose or missing Fuel Filler Cap
- Damaged Locking tabs on Fuel Cap and/or fill tube
- Damaged seal points on Fuel Cap and/or fill tube
- Fuel cap gasket seal

Were any of the above conditions found?

Yes

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 4

4. INSUFFICIENT VACUUM SUPPLY TO THE EVAP PURGE SOLENOID
1. Carefully inspect the Evap Purge Solenoid vacuum supply hose for proper routing.
2. Check for a pinched or plugged hose from the throttle body or intake manifold to the Purge Solenoid.
3. 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. Powertrain Verification Test.

No

- Go To 5

5. EVAPORATIVE PURGE HOSE/TUBE AND FRESH AIR FILTER OBSTRUCTION
1. 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.
2. 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. Powertrain Verification Test.

No

- Go To 6

6. EVAP PURGE SOLENOID

NOTE: To continue testing you will need the Evaporative Emission Leak Detector (EELD).

WARNING: Keep lit cigarettes, sparks, flames, and other ignition sources away from the test area to prevent the ignition of explosive gases, Keep the test area well ventilated.

1. Connect the red power lead of the EELD to the battery positive terminal and the black ground lead to battery negative terminal.
2. Disconnect the vacuum hoses at the Evap Purge Solenoid.
3. Connect the SMOKE supply tip (black hose) to the "CAN" port on the Evap Purge Solenoid.
4. Set the smoke/air control switch to SMOKE.
5. While still holding the remote smoke/air start button, check to see if smoke is exiting the purge valve. This indicates that there is a leak internal to the purge valve.

NOTE: This is an optional method of checking the purge valve for leaks if the EELD is unavailable.

6. Disconnect the Smoke supply tip from the vacuum supply hoses at the Evap Purge Solenoid.
7. Using a hand vacuum pump, apply 10 in Hg to the "CAN" side of the Evap Purge Solenoid.
8. Observe the vacuum gauge for at least 15 seconds.

NOTE: The solenoid should hold vacuum for a minimum of 15 seconds.

Is smoke visible from the Evaporative Purge Solenoid or NOT hold a vacuum?

Yes

- Go To 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. Evap Purge Solenoid - Removal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

7. POWERTRAIN CONTROL MODULE (PCM)
1. 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. Powertrain Verification Test.

No

- Replace and program the Powertrain Control Module. Powertrain Control Module - Removal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.