gas cap fault but not gas cap

[agood01]

Gas Cap Fault, We have a gas cap leak fault but the gas cap was replaced and did not make a difference. We did a smoke test and the only smoke we saw was out of the fresh air assembly next to the fuel fill hose. Don't know if that should have happened but that was the only leak. Also I can't find where the fuel vacuum pressure sensor is. Any help would be great.

 

[CheddarGau]

Gas Cap Fault, We have a gas cap leak fault but the gas cap was replaced and did not make a difference. We did a smoke test and the only smoke we saw was out of the fresh air assembly next to the fuel fill hose. Don't know if that should have happened but that was the only leak. Also I can't find where the fuel vacuum pressure sensor is. Any help would be great.

You try to pinch of the hose at the vent valve hose and see if that will pressurize the system and check for leaks that way. What year of KJ do you have?

 

[Robochop]

Gas Cap Fault, We have a gas cap leak fault but the gas cap was replaced and did not make a difference. We did a smoke test and the only smoke we saw was out of the fresh air assembly next to the fuel fill hose. Don't know if that should have happened but that was the only leak. Also I can't find where the fuel vacuum pressure sensor is. Any help would be great.

My 2007 has the same "gas Cap" code in the odometer block but also getting codes P0456/7 for evap

 

[agood01]

You try to pinch of the hose at the vent valve hose and see if that will pressurize the system and check for leaks that way. What year of KJ do you have?

This is a problem with lots of 2007 Libertys. Even the dealer can't give a reason it happens. They will do a factory computer check but they said most parts are no longer available through them. They did change that gas system vents in 2007.

 

[Pharunk]

This is a problem with lots of 2007 Libertys. Even the dealer can't give a reason it happens. They will do a factory computer check but they said most parts are no longer available through them. They did change that gas system vents in 2007.

I have a 2012 KK. Got the same code ended up changing my fuel tank expansion canister which solved the issue. 30 bucks at advance auto. Located directly next to and actually resting up against the battery.

 

[klc]

Check the hoses connected to the Evap solenoid up front. Mine had a hole worn through where they pass close to the battery.

 

[Puddle Jumper 2.0]

I have a separate thread going on this as well. I replaced the gas cap, purge control solenoid (next to battery), the switch on my evaporator canister by gas tank all with MOPAR parts and erased all codes with my scan tool and as soon as I started the rig that stupid “GASCAP” message popped up on my dash in the odometer field! My next idea is to pull the rear splash shield and inspect the filler tube assembly that goes into the gas tank…… I am tempted to run the tank down to nothing (maybe one or two gallons of fuel) and drop it down to get better access for inspecting vac lines back there. I am wondering if there is some debris that has worn a hole in one of the lines??? Even though this jeep has lived all of its 180,000 mikes of life on paved roads with next to nothing on gravel roads with the exception of the “chip seal” replacing that DOTs live to put on our roads instead of actually fixing them….. as I move through this I will post each step of the way. Thanks to all!!!