Operation CHARM: Car repair manuals for everyone.
Home >> Fiat >> 2012 >> 500c L4-1.4L >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> P Code Charts >> P0441

P0441






P0441-EVAP PURGE SYSTEM PERFORMANCE

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. At key off, the Powertrain Control Module (PCM) monitors the Evaporative System Integrity Monitor (ESIM) Switch. As the fuel and air in the Fuel Tank cools, a vacuum will occur naturally inside the tank. One inch of vacuum will cause the switch to close. If the PCM sees the switch close before the counter reaches a calibrated amount, the monitor passes.

The monitor is a two stage test and runs only after the Evaporative system passes the small leak test. Stage one is non-intrusive. With the engine running, the monitor will first evaluate the delta pressure change of 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. The intrusive test runs only if stage one does not pass. 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 (39°F) and 35°C (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.

Diagnostic Test

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: 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. CHECK THE FUEL TANK PRESSURE (FTP) SENSOR 5-VOLT SUPPLY CIRCUIT FOR AN OPEN/HIGH RESITANCE

NOTE: Diagnose and repair any system voltage or sensor supply voltage DTC's before continuing with this test.
Turn the ignition off.
1. Disconnect the FTP Sensor harness connector.
2. Ignition on, engine not running.
3. Measure the voltage on the FTP Sensor 5-Volt Supply circuit at the FTP Sensor harness connector.

Is the voltage between 4.8 to 5.2 Volts?

Yes

- Go To 4

No

- Repair the Fuel Tank Pressure Sensor 5-Volt Supply circuit for an open or high resistance.

4. FUEL TANK PRESSURE (FTP) SENSOR
1. Turn the ignition off.
2. Re-connect the FTP Sensor harness connector.
3. Remove the fuel filler cap.
4. Ignition on, engine not running.
5. With a voltmeter, back-probe the FTP Sensor 5-Volt Supply circuit at the FTP Sensor harness connector.

Is the voltage between 2.3 to 2.7 Volts?

Yes

- Go To 5

No

- Verify that there is good pin to terminal contact in the Fuel Tank Pressure Sensor and Powertrain Control Module connectors. Replace the FTP Sensor if no problems were found with the connectors. .
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

5. EVAP SYSTEM INSPECTION
1. Visually and physically Inspect the entire Evaporative Emission 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 Filler Cap or seal
- Improper installation of the Fuel Cap
- Damaged locking tabs on the Fuel Filler Cap and/or filler tube
- Damaged seal points on the Fuel Filler Cap and/or filler tube

Were any problems found?

Yes

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

No

- Go To 6

6. INSUFFICIENT VACUUM SUPPLY TO THE EVAP PURGE SOLENOID
1. Turn the ignition off.
2. Inspect the Evap Purge Solenoid vacuum supply hose for proper routing and installation.
3. Check the vacuum supply hose between the throttle body or intake manifold and the Evap Purge Solenoid for any obstructions or blockage.
4. Check the vacuum port at the throttle body or intake manifold for any obstructions or blockage.

Were any problems found?

Yes

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

No

- Go To 7

7. EVAP PURGE HOSE/TUBE OBSTRUCTION
1. Inspect the Evap 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 is not damaged or kinked and is free from any obstructions or blockage.

Were any problems found?

Yes

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

No

- Go To 8

8. EVAP PURGE SOLENOID

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. Failure to do so may result in possible serious or fatal injury.

NOTE: After disconnecting the Evap Purge Solenoid vacuum connections, inspect the lines and solenoid for signs of contamination.

1. Disconnect the vacuum hoses at the Evap Purge Solenoid.
2. Using a hand vacuum pump, apply 10 in. Hg. to the "CAN" side of the Evap Purge Solenoid.

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

3. Turn the ignition on, engine not running.
4. Using the scan tool, actuate the Evap Purge Solenoid to the ON position.

NOTE: The vacuum should drop when the solenoid is actuated.

Does the solenoid function as described above?

Yes

- Go To 9

No

- Verify that there is good pin to terminal contact in the Solenoid and PCM harness connectors. Replace the Evap Purge Solenoid if no problems were found in the connectors.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

9. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Evap Purge Solenoid, ESIM Switch and the PCM.
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Perform any Technical Service Bulletins that may apply.

Were any problems found?

Yes

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

No

- Replace and program the Powertrain Control Module (PCM). .
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

pro multis · About Operation CHARM