When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I think I have, mine was not venting and the truck ran goofy and when you pulled the cap you could hear the tank go back to shape. Cant remember if it was sucking shut or blowing up. It must of been easy if I cant remember doing it....lol. The sensor would watch tank pressure to open/close a vent for emissions. I just thought if the sensor is on the tank, that could be fun....either pull the box which sucks cuz of the frame clips breaking or drop the tank....not fun either do to the fuel line connections being full of gunk and not releasing.
I do know that there is a controlled vent to control pressure in the tank but dont remember what it was called, the more I think about it it was collapsing the tank bad enough to actually watch it and the truck acted like it was vapor locking.
There is definitely a fuel tank pressure sensor. All the EVAP monitor tests (leak, gas cap off, canister vent / purge) are based on it. If the DTC is 'out of range' either direction (like -20 or +5 InH2o), it could be the result of other failures and not the FTP Sensor. Such as the EVAP purge valve / or the EVAP vent solenoid - or even possibly a clogged up evaporative system canister.
It is located on the tank near the Fuel Level Sensor. But hopefully the problem is one of the simpler things.
Yeah, I've been goofing with all the OBDII parameters associated with the EVAP system trying to perfect formulas for a useful Torque Pro EVAP diagnostic screen. The system has proven to be confounding. Fuel Tank Pressure is stupid crazy to figure out a (halfway) workable formula for displaying in InH2O, which seems to be the units the PCM uses to trigger DTCs. Took a while to figure out WHY - I was having so much trouble recreating prior tests after making changes!!
Found out - All EVAP monitors are suspended if IAT is >100 degrees or Tank level is < 25% - > 75%. That 100º thing has been a problem here in South Texas, this summer. And all this effects OBDII Monitors Complete flag that keeps members from being able to pass inspection.
Then I found what it kept doing ALL the time - is constantly checking for 'in flight re-fueling' & Gas Cap off. It's a pretty complex (but fascinating) system.
Last edited by F150Torqued; 08-27-2017 at 01:49 PM.
Reason: formatting
There is definitely a fuel tank pressure sensor. All the EVAP monitor tests (leak, gas cap off, canister vent / purge) are based on it. If the DTC is 'out of range' either direction (like -20 or +5 InH2o), it could be the result of other failures and not the FTP Sensor. Such as the EVAP purge valve / or the EVAP vent solenoid - or even possibly a clogged up evaporative system canister.
It is located on the tank near the Fuel Level Sensor. But hopefully the problem is one of the simpler things.
08-24-2017, 09:53 PM
Fuel tank pressure sensor 2008
