P0441-EVAP PURGE SYSTEM PERFO... P0441-EVAP PURGE SYSTEM PERFORMANCE

P0441-EVAP PURGE SYSTEM PERFO... P0441-EVAP PURGE SYSTEM PERFORMANCE

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

Theory of Operation EVAP SYSTEM COMPONENTS CALLOUT DESCRIPTION 1 Filter 2 Evaporative System Integrity Monitor (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 10 Fuel Cap (if equipped) or Capless Fuel Filler Flap EVAPORATIVE SYSTEM OVERVIEW: The Powertrain Control Module (PCM) monitors the Evaporative Emission System operation. The primary concern being monitored is the integrity of the system against leaks. The operation of the Purge Solenoid and evaporative purge flow is also monitored. This is accomplished using inputs from the ESIM Switch and Fuel Tank Pressure Sensor. PURGE FLOW MONITOR: The Purge Flow Monitor will only run if the Small Leak Monitor recorded a pass on the previous ignition off event and the test data was valid. Because the leak detection diagnostics can only verify that the fuel tank system is sealed while the purge valve is closed, it cannot determine if the purge line between the solenoid and Intake Manifold is pinched or leaking. The Purge Flow Monitor is needed to verify these failure modes. The Purge Flow Monitor works on the premise that as flow through the system increases, so does the pressure drop in the system. The PCM monitors the Fuel Tank Pressure Sensor and looks for increasing vacuum in the Fuel Tank with increasing purge flow. Conversely, it looks for decreasing vacuum in the Fuel Tank with decreasing flow. With the engine running and enable conditions met, the non-intrusive purge monitor looks for a calibrated increase in vacuum in the fuel tank with increased purge flow, referred to as phase 1. If phase 1 passes, the purge monitor looks for a calibrated decrease in vacuum in the Fuel Tank with decreasing purge flow, referred to as phase 2. If phase 2 passes, the purge monitor is complete. If the purge flow monitor fails either phase, or does not complete both phases within a specified time, an intrusive test is initiated to verify the results from the non-intrusive test. The intrusive diagnostic uses the same two phases to analyze the system. However, the intrusive test actuates the Purge Solenoid such that the differences are much more pronounced allowing a more accurate test result. If the PCM detects a failure during the intrusive test, a purge system performance fault is set (P0441). VALID SMALL LEAK MONITOR EVENT: This is an accumulative monitor and the data from each valid event is recorded and added to the previously recorded events. The PCM timer records the engine on/drive cycle and engine off time for each small leak monitor event. For an event to be valid the PCM must see; An engine on/drive cycle for a minimum of 10 minutes. NOTE: The engine on timer will stop counting after a maximum of 26 minutes. And, when the engine is shut down, an engine off timer starts. There is a 12 minute delay time in which the PCM will ignore ESIM Switch input. The engine off timer period will continue to count until one of the three conditions exist: The engine is started without a switch closure during the event. NOTE: At the next key on cycle a determination is made as to whether the event was valid and the information is kept. An ESIM Switch closed input is received after the 12 minute delay during the event. NOTE: If the switch closed input is received, the PCM records that the switch has closed, stores the engine shut down time, then goes to sleep. After a maximum of 1051 minutes without an ESIM Switch closure during the event.

When Monitored: With the engine running, after the Evap System small leak test has passed. Set Condition: If the 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 FUEL TANK PRESSURE (FTP) SENSOR 5 VOLT SUPPLY OPEN CIRCUIT OR EXCESSIVE RESISTANCE EVAP PURGE SOLENOID VACUUM SUPPLY EVAP PURGE HOSE/TUBE OBSTRUCTION FUEL TANK PRESSURE SENSOR EVAP PURGE SOLENOID EVAPORATIVE SYSTEM INTEGRITY MONITOR SWITCH (ESIM) POWERTRAIN CONTROL MODULE (PCM) Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC- Based Diagnostics/MODULE, Powertrain Diagnostic Test 1.VEHICLE HISTORY AND SERVICE BULLETIN INVESTIGATION 1. Turn the ignition on. 2. Using the scan tool, read DTCs. Record the related Freeze Frame data if any DTCs are present. 3. 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 vehicle inspection or service bulletin repaired the customer's complaint. Testing complete. A DTC is present, the vehicle inspection revealed no concerns, no service bulletins apply, or the service bulletin did not repair the customer's complaint. Go To 2 2.ACTIVE DTC NOTE: Because a hot vehicle can conceal a potential leak, allow the vehicle to reach ambient temperature before continuing with this procedure. NOTE: A loose fuel filler cap could caused this DTC to set. Make sure the fuel filler cap is tight and in good condition.

NOTE: If the customer is experiencing an early fuel shut off during the fuel filling process in addition to DTC P0440, P0441, or P0452, check for restrictions in the Evap 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. Using the scan tool, read DTCs. Is the DTC Active or Pending at this time? Go To 3 Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension. Perform the INTERMITTENT CONDITION diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain 3.CHECK THE FUEL TANK PRESSURE (FTP) SENSOR 5 VOLT SUPPLY CIRCUIT FOR AN OPEN/HIGH RESISTANCE 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? Go To 4 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. Reconnect the FTP Sensor harness connector. 3. Remove the fuel filler cap. 4. Turn the ignition on, engine not running.

5. With a voltmeter, back probe the FTP Sensor Signal circuit at the FTP Sensor harness connector. Is the voltage between 2.3 and 2.7 volts? Go To 5 Verify that there is good pin to terminal contact in the Fuel Tank Pressure Sensor and Powertrain Control Module connectors. If no problems were found with the connectors, replace the Fuel Tank Pressure Sensor according to the service information. 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 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? Repair as necessary. Go To 6 6.INSUFFICIENT VACUUM SUPPLY TO THE EVAP PURGE SOLENOID 1. Inspect the Evap Purge Solenoid vacuum supply hose for proper routing and installation. 2. Make sure the vacuum supply hose between the throttle body or intake manifold and the Evap Purge Solenoid is free from any obstructions or blockage. 3. Make sure the vacuum port at the throttle body or intake manifold is free from any obstructions or blockage. Were any problems found? Repair as necessary. Control (PCM) - Standard Procedure)

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? Repair or replace as necessary. 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. 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? Go To 9 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.

9.POWERTRAIN CONTROL MODULE (PCM) 1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the 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? Repair as necessary. Replace and program the Powertrain Control Module (PCM) in accordance with the service iinformation. (Refer to 08 - Electrical/8E - Electronic Control Modules/MODULE, Powertrain Control - Removal). Portions of materials contained herein are sourced from Chrysler Corporation. Copyright 2007-2014 Service Repair Solutions, Inc.