Diagnose and fix P0441 Dodge
A P0441 Dodge trouble code is from the Evaporative Emissions System. See this post for a primer on how evaporative emissions systems work and this post on how Chrysler and Dodge system test for evaporative emissions. In general, the system prevents gasoline vapors from entering the atmosphere during fill-up by absorbing the vapors in a charcoal canister. Later, when the engine is running, a purge and vent valve open which allows the engine to suck the gas vapors into the engine and burn them while allowing fresh air into the canister to ventilate it. Once the purge process is complete, both valves close and the system tests for leaks.
Some car makers apply a vacuum to the closed system and then close the vacuum and watch sensors to see if they lose the vacuum charge. Chrysler does it differently. They rely on a basic law of physics that says that a volatile fuel in a sealed system will change pressure based on temperature.
See this post to understand how the Chrysler ESIM works
See this post to understand how Evaporative Emissions Systems work
P0441 set conditions
Before the vehicle will test the evaporative emissions system it must first meet these criteria
• The Evaporative System Integrity Monitor (ESIM) Switch closed during last ignition off cycle or the large leak test is active.
• Battery voltage above 11.0 volts.
• Fuel level is between 12% and 88%.
• Ambient temperature is between 4°C (39.2°F) and 35°C (95°F).
• Engine run time since start is less than 30 minutes.
• No Purge Solenoid control circuit DTCs active.
P0441 will set if
The Powertrain Control Module detects that the change (delta) in fuel tank pressure is below a calibrated threshold during side 1 (Purge Solenoid ramped up) or side 2 (Purge Solenoid ramped down) of both the nonintrusive and intrusive diagnostic.
P0441 Dodge Possible Causes
FUEL TANK PRESSURE (FTP) SENSOR 5-VOLT SUPPLY OPEN/HIGH RESISTANCE
PURGE SOLENOID VACUUM LINE LEAKING OR BROKEN
PURGE SOLENOID VACUUM LINE OR PORT RESTRICTED/OBSTRUCTED
PINCHED/OBSTRUCTED LINE BETWEEN THE PURGE SOLENOID AND CANISTER
PINCHED/OBSTRUCTED LINE BETWEEN THE CANISTER AND FUEL TANK
FUEL TANK PRESSURE SENSOR
How to diagnose P0441 Dodge
Start by checking the hoses to the purge solenoid. Look for cracks in the hoses, pinched areas or internal restriction. Also check to make sure there’s no liquid gas or charcoal grains in the lines. If you find charcoal, that’s an indication that the charcoal canister has failed.
Using a bi-directional scan tool, command the purge valve to open and close. If you don’t have a scan tool, apply power and ground to the solenoid. Apply vacuum to one side of the purge valve and make sure it holds vacuum when closed and opens and closes easily when operated.
Next, check the Evaporative System Integrity Monitor (ESIM) vacuum switch by blowing gently into the ESIM unit through the vent hose. Do this while checking the voltage on the violet/grey wire. The voltage should drop to 0-volts while blowing into the line. If it doesn’t check the ground connection at the brown/white wire. If the ground connection is good but the voltage doesn’t drop the ESIM is faulty and must be replaced.
Next, check the fuel tank pressure (FTP) sensor. Remove the gas cap. Then turn the IGN to ON but don’t start the engine. Using a voltmeter check the FTP. With the cap off, voltage should read between 2.3 and 2.7 volts.
Most commonly replace parts to correct a P0441 Dodge trouble code
©, 2019 Rick Muscoplat