Fuel tank pressure sensor-po453

[glindy]

Trying to fix 453 for emissions inspection on 2000 ranger 4x,but not sure if sensor is the issue.
Pulled sensor plug and the red wire has 5v,black wire 0/no cont to frame ground,blue wire also has 5v, KOEO.
Found testing ftp checks but they refer to brown/grey/white wires as signal/power/pcm wires, so I have no idea if my readings are OK for sensor plug?
Had already replaced vapor mgt valve and charcoal purge valve to no effect on 453.
Can't find a testing procedure for my red/black/blue plug,to see if wiring is OK.

 

[glindy]

Think I found the issue. Pulled bed to get to the ftp and found a pigtail connector on frame that has another 4 wires to tank. went to put dielectric grease in it and it didn't seem seated all the way. Greased up both fittings and decided to check voltage again. This time red was 5.02,blue 5.02, but black now had a .002 ground to frame reading. Ran truck for 30 min,revved it up and no more 453. Hopefully this fixed the issue.

 

[Winger1]

We could have similar issues but I might be able to help. The PCM supplies a regulated +5VDC (RED wire) along with a ground (BLACK wire) to the FTPS. With your VOM meter, black lead grounded somewhere - you'll see 0V on the ground and +5 on another. A third wire (probably BLUE) feeds back to the PCM which if your FTPS is working correctly indicates 1/2 the 5V to about 2.5V at atmospheric pressure ie. outside of the tank or vapour line. As vapour pressure increases ie. inside the tank the 2.5V will proportionately decrease towards 0V.

So test the sensor outside the tank first by monitoring these voltages. I ran across an interesting post where someone found their 5V line actually measured about 3.5VDC - 1/2 voltage feeding back from a good FTPS was not enough voltage to pass the EVAP test!! The cure was a new PCM board - had a bad voltage regulator on it. In your case you indicated 5V on the blue wire which looks like its shorted to the supply line - bad sensor???

Good luck hope this helps and would you know if my '06 3.0L has the sensor in the tank as well???? Thanks.

 

[glindy]

I would say 06 is also top of tank pump. my cel hasn't gone off again after cleaning FT harness assm conn,so I haven't changed the ftp,but have one if I need to. Have the bed off to do some welding,but could probably change ftp in place if needed.Thinking about a 2-3in body lift when I have the $$$.