2017 Ecoboost with P051B check engine light

[Rosko]

Hi all, I'm hoping that someone could point me in the right direction as to where I can locate the Crankcase pressure sensor on my 3.5L ecoboost?

2017 Expedition EL Limited (64k miles).

I have a check engine light and the code is P051B Crankcase Pressure Sensor Circuit Range/Performance.

I was going to try to locate/clean the sensor but I couldn't find where the sensor is located. I tried to search F150 forums for the first gen 3.5L, and I was surprised I didn't see any Youtube videos or websites/diagrams locating it.

Any help is appreciated.

 

[AllBoostNoEco]

Hi all, I'm hoping that someone could point me in the right direction as to where I can locate the Crankcase pressure sensor on my 3.5L ecoboost?

2017 Expedition EL Limited (64k miles).

I have a check engine light and the code is P051B Crankcase Pressure Sensor Circuit Range/Performance.

I was going to try to locate/clean the sensor but I couldn't find where the sensor is located. I tried to search F150 forums for the first gen 3.5L, and I was surprised I didn't see any Youtube videos or websites/diagrams locating it.

Any help is appreciated.

I also can’t find anything 3.5 Ecoboost specific, but seems like the other variations it is the PCV line. Check that and see if there is any sort of electronic module in the line.

 

[Bigfishfin]

Had the same issue on my 2015 last fall. The dealer tried to get $250 out of me for a PVC valve and diagnosis, but I screamed real bad since I had the truck in just a few months earlier, for the same issue, when it was still under full factory warranty. The light came back on and the problem was finally solved with a replacement PVC hose. Something about a restriction as I recall.

 

[Rosko]

I ordered a PCV valve. I might order a new Crankcase pressure sensor if the PCV valve/tube doesn't fix the issue.

On a different note, I changed the oil today, it looks like the dealer overfilled the oil the last time (though not by much). I got out just over 6qts. so that might have something to do with it as well (not counting what spilled out and whats left in oil filter).

I'll try to update this thread as I progress through this problem/code, hopefully it'll help out future owners that will surely find it via google.

 

[Rosko]

Update:

I ended up taking my existing PCV valve out, remove the tube and inspected. Both looked OK. The PCV valve sounded like it was working properly, I just reinstalled and put the tube back on. I went out for a drive, about 10 miles and drove it a little harder than normal, but nothing crazy. I shut it off at the dealer, scheduled my service appointment, then came back out and started it again, the check engine light is now off.

I'm not sure if it was coincidence, but I'm guessing changing the oil/putting in the correct amount of oil had something to do with it. I doubt removing/reinstalling the PCV tube and valve had anything to do with it.

Hopefully it doesn't come back on again, but I'm leary that it will.

 

[Rosko]

Well the CEL came back on yesterday. I guess I'll have to take it in to see if the dealer can figure out what's wrong. Grrrrrr.

 

[tater]

I had the same issue. My 2015 with 50,000 miles had the same code come up about 2 weeks ago. I had scheduled an appointment at the dealer to have it checked out. Prior to going I checked the oil to find it had been over filled (had my oil changed about a week earlier). Took it back to the shop where they drained oil to get it back to normal. Light has been off since. Hope that solves the issue.

Keep in mind that it should be covered under emissions warranty (6yr/80,000). I had quite a little spat with my local dealer who advised I would have to pay for diagnostic, etc. It states right in your warranty that Ford will cover all cost including diagnostic, parts, etc., to repair the issue. I thought about chasing and repairing problem myself but if it's covered I'll let them do the work.

 

[Rosko]

Thanks for the response Tater.

My CEL just went off again...before I have my appointment scheduled. I'm wondering if there's some residual oil/gunk somewhere that keeps triggering it, or preventing/causing too much crankcase pressure since the code says "out of range".

I guess I'll wait to see what happens. I'm likely going to sell the expedition here soon, but don't want to sell it with the CEL issue.

 

[rjdelp7]

Excessive crankcase pressure is serious. It could be from piston 'blow by'(cracked, melted pistons or bad rings) or a blocked exhaust. Do you hear a hiss of air escaping, right after switching off the motor? Crankcase pressure can be relieved by pulling the dip stick out, about an inch. It will vent it, through the dip stick tube.

 

[Boostedbus]

Look for this hose on the drivers side. The sensor plugs in the hole in the middle. Sorry I don’t have a pic of the actual sensor,but take it out and clean it and make sure it’s up in the hose so oil can’t puddle in it.