maroon jk

My engine light just came on. And I was told it has to do something with my gas. And all I can think of is my gas filter. Has this happened to anyone? And any thoughts of what it might be??

genesbro

Was it an evap code, lean code, ??

Absolute

Any more info would help, Read this thread to self diagnose the code, then check back and let us know what you found.

https://www.jk-forum.com/forums/show...agnostic-Codes

Roos85

Mine came on recently for an evap code. I didnt put the cap on tight enough. See if thats it.

derby911

Also you don't have a gas filter (built in the pump assembly)

maroon jk

Thanks ALOT bondsy! I checked it and two of them came up, no clue what they mean?

P0456- evap purge system small leak.
P0440- general evap system failure.

Can anybody please tell me what they mean? And how can I fix it please ? Thank you so much! <3

maroon jk

And what is an evap??

ronjenx

You probably meant there is no easily replaced gas filter.

But, to clarify:

Two fuel filters are used. One is located at the bottom of the fuel pump module. The other is located inside the module. A separate frame mounted fuel filter is not used with the JK. Both fuel filters are designed for extended service. They do not require normal scheduled maintenance. Filters should only be replaced if a diagnostic procedure indicates to do so.

33 williys 77

http://www.youtube.com/watch?v=IzfR84T6pBY

33

ronjenx

Fuel tank pressure vents into the EVAP (Evaporative Emissions) canister. Fuel vapors are temporarily held in the canister until they can be drawn into the intake manifold.

A loose gas cap will through any of several codes, so check that first.

Here is what your codes mean:

P0440-GENERAL EVAP SYSTEM FAILURE


Theory of Operation


The Evap 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 Evap system passes the small leak test. Stage one is non-intrusive. The PCM monitors the purge vapor ratio and the ESM switch closed ratio. If the purge vapor ratio is above a calculated value, the monitor passes. If the ESM 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: Engine running after a cold start with the difference between ECT and AAT is less than 10° C (19° F). Fuel Level between 12% and 88% full. Manifold vacuum greater than a calculated minimum value. Ambient Temperature between 4° C and 32° C (39° F and 89° F).
• Set Condition: When the monitor conditions are met, the PCM will ramp in purge flow. If the PCM does not sense an ESM switch closure after a calculated amount of purge flow accumulation, an error is detected. Two Trip Fault. Three good trips to turn off the MIL.

Possible Causes
EVAP PURGE SOLENOID VACUUM SUPPLY
EVAP PURGE HOSE/TUBE AND FRESH AIR FILTER OBSTRUCTION
(Z905) GROUND CIRCUIT OPEN
(K107) ESM SIGNAL CIRCUIT OPEN
EVAPORATIVE EMISSION LEAK
EVAP SYSTEM MONITOR SWITCH
EVAP PURGE SOLENOID
POWERTRAIN CONTROL MODULE (PCM)


P0456-EVAP PURGE SYSTEM SMALL LEAK

• When Monitored: With the ignition off, fuel level less than 88%, ambient temperature between 4° C and 43° C (39° F and 109° F), and the fuel system in closed loop.
• Set Condition: As temperatures change, a vacuum is created in the fuel tank and EVAP system. With the EVAP system sealed, the PCM monitors the ESM switch. If the ESM switch does not close within a calibrated time, an error is detected by the PCM. One Trip Fault. Three good trips to turn off the MIL.

Possible Causes
EVAP PURGE SYSTEM LEAK
EVAP PURGE SOLENOID
EVAP SYSTEM MONITOR SWITCH