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2016 Jeep Renegade trailhawk 2.4l No noticeable symptoms. I keep having this code pop up intermittently, and I'd like to get to the root cause of it. I understand it has to do with the evap system, and possibly the purge solenoid, but I'd like to be sure before just replacing stuff.
Not entirely necessary if you have a way to regulate compressed air to 1-2 psi and a spray bottle with soapy water to spray the evap lines and the canister purge valve in back of car and purge solinoid at engine while air is being supplied to line. Just look for bubbles and thats your leak.
If not able to do that then use the vac pump at evap test port with valve core removed from test port. Apply vacuum to -10 psi. Check for vac to return to zero if it does disconect purge solinoid at engine and plug evap line. Reapply -10 psi of vac with pump and recheck. If it stays the same then hook up vac pump to engine side of purge solinoid vac line. Apply vac to -10 psi. If it holds vac then move to the canister purge valve under car. If it does not hold vac then this would be the faulty part.
Under car with canister vent valve apply bubbles around valve and apply vacuum look for bubbles to shrink or disappear this would be the leak point if its the valve then it is defective.
According to the code set criteria for P0441, the EVAP Small Leak test has to have already passed during the last key off cycle before the purge performance test will run. So, I wouldn't chase leaks at this point.
Service info also says the purge performance is gauged with the Fuel Tank Pressure sensor and not the ESIM switch. That helps to narrow your list of suspects.
First step is to check the FTP sensor reading, KOEO. What does it indicate?
Second is to use the purge bidirectional function to open the purge with the engine idling. Watch the FTP and fuel trim PIDs at the same time. The FTP should indicate a vacuum, and the trims should go negative.
If you see negative trims but no change in the FTP reading, I'd say the FTP sensor is stuck. If you don't see negative trims, I'd suspect a stuck closed purge valve.
Ok, FTP is 652 kpa koeo, both of my scan tools will not allow me to activate the solenoid with the engine idling, it gives an error of conditions not met.
I was able to activate it with the engine off, and the pressure went up .5kpa
As far as Alfaobd, I like it, I also have a Snap On Ethos Tech, which is nice for my non FCA vehicles, but alfa has some functions/controls that Snapy doesn't. Off the top of my head, you can change configs, program new fobs (on some vehicles, with PIN) and a few others I haven't used.
652 Pa is about two inches of water, which isn't an insignificant amount for an EVAP system. That's enough to fool the PCM into thinking the purge valve isn't working correctly. Definitely suspicious of the FTP sensor now. It should read pretty darn close to zero KOEO.
Just for fun, try checking the FTP again, KOEO with the gas cap removed. Still reading 652 Pa?
Great tips here. It might not let you open the purge at idle. Standard routine on Nissan's is to look at ftp voltage at about 2k rpm and open the purge all the way. Looking for only about a 100mv of press drop, since the vent valve is open. If it keeps going down you can expect a restriction in the system, acting as a closed vent. Disconnecting hoses will isolate where it is. I imagine this application could be applied on most systems. If your fuel trims are lean at idle, you can pinch off the purge vacuum line and if they get better then the purge valve is leaking.
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