i'm hoping/gessing all years are the same, but here is what i need...

just in front of the drivers rear tire, and above the frame rail, sitting on top of the fuel tank, is the vapor canister, it has a hose, aprox 5/8 in diameter that runs forward and goes into the frame rail, where the connects hose connects to the vapor canister, there is an evectric valve, aka leak detection pump

i have tried with the key on, and with the engine started. i tried pluging and unpluging, in either situation, and i hear no noise or vibration of any sort that would tell me the pump is doing anything.

my gas cap warning is on at all times and throwing an engine code because of it, causing a few different issues and driving me nuts, let me know if you can find anything different, or if this is normal, thanks


ok... after alot more reasearch, i found that it is actually just a valve, even tho its called a "pump" and i hooked my multimeter up to the wires and got a reading of 4.7 volts at all times, IDK what to make of this????

 

Just looked but couldnt see much, its dark out. I will look again and check voltages tomorrow, but I couldn't see above the fuel tank at all. could you possibly post a pic of the valves location maybe?

 

If I have time today, I will check it out..

 

thanks guys, i dont have a pic as its been raining since last night, its probably a lot eaiser with the body lift, but i just stuck my head between the frame rail and the bed side to see it. its white in color, about the center of the tank, just above the frame rail, and has a two wire plug and the hose coming off, going foward

 

You are correct, there isn't a PUMP really in the EVAP system anymore. It's just a switch inside a diphragm chamber. Called an ESIM Switch. The wires are the signal and the ground. The Purge solenoid does the pumping now during the test and the PCM watches for a voltage change on that wire in a predetermined amount of time. (Short Story) The newer EVAP systems have been relatively trouble free compared to earlier ones. There aren't any pushed on rubber hoses much anymore. Everything is plastic hose with a quick connect.

FYI...the trouble spots have mainly been the internal ESIM malfunction and the round gasket that seals them to the canister.

 

You likely won't see any changes in the signal without the vehicle moving. most purge systems like that only purge while the vehicle is in motion.

 

six shooter has a good view on it. I mean really you are gonna need to drve with it off to have any effect cause sitting still i would assume no load...nothing being forced to it...try resetting your PCM by disconnecting the battery to see if that takes care of it!