I recently returned with a code P1494 evap vent switch or mechanical fault. Possible cause aa-1 open or short circuit condition, aa-2 poor electrical connection, aa-3 failed vent solenoid, aa-4 vacuum hose plugged. Any info on my next step will be welcome.
Sorry about stepping on coach thread earlier today.

 

P1494 Jeep Leak detection pump pressure switch or mechanical fault
Dont really have anything to add right now, if this headache goes away Ill look through my FSM.
Im sure someone will come along.

 

Sounds like another pita green problem. A slolenoid control on the charcoal evap cannister capturing the evap from your gas tank. The solenoid can stick and bring on the fault as some gas evap may now be escaping into the atmosphere contributing to global warming. Son in law had to replace the solenoid eventually, 1st time round a good clean up with WD40 got rid of the fault for about a year. 2nd place to look is your gas cap sealed, on newer vehicles codes of this nature can be triggered by loose gas cap or cap with dirty o-ring. The effect is not hurting your jeep but the code is a pita and if you don't get it off the dash you may miss a more important code in the future.

 

Start with an inspection of all components and hoses around the leak detection pump.

Could be the solenoid itself here......

 

check the vacuum supply hose to the leak detection pump, most likely the elbow fitting at the manifold is leaking.

 

I Have a worn hole in a plastic air line. I temp repair with elec tape.
I had an elbow air line off under the rail. I plugged it back in.
Check Engine light was on. Code p1494. I reset the panel by disconnecting battery cables and holding them together for 20 secs. I reconnected the battery and the panel is clear.
She was idle up and down about each 10 seconds.

I thank you all. Pictures are in the album. I will order the tube at the parts store.
The cherokee idles smooth now. I will run about 65 miles round to work in a.m.
I put 6 fresh qts penzoil high mileage and filter into her courtesy jiffy lube and she give us a wink and a little smile.