Hi All,

An interesting problem I am having, but feel someone on here may have had the issue before.

Just recently replaced the driver side 4wd actuator. When testing the system to see if it was working, I noticed that in 2wd everything seemed to be in order (wheel spun without the half shaft, no grinding noises on test drive, seemed good to go).

However, when I switched to 4hi, the dash light "4HI" would come on but the wheel still spun freely without the half shaft. When the truck was off, the wheel and half shaft spun together as they should when vacuum is released from the actuator. When I switched to 4lo, the dash light did not come on and the check engine light came on. Pulling codes revealed P0171 and P0174.

Could these codes be caused by a bad solenoid? Is the solenoid not switching the vacuum off and that's my issue? Are there other possibilities?

Thanks all in advance!

 

Vacuum leak in the IWE system.

 

I found this video helpful.
https://m.youtube.com/watch?v=m6b7FQOsbvI&feature=youtu.be

 

Is it plugged up with crap?? I had to replace mine. But if you look at the way the lines are run you'll laugh. If you're doing any dirt road driving it sucks straight in. I took mine to ford because it was saying it was in 4x4. It was not engaging. They replaced my actuators because I didn't have time myself due to work. Did not fix the issue. We ended up re routing the line and haven't had 4x4 problems since.

 

Nothing was plugged up, and not a leak in the IWE system. The solenoid was bad (already was the "updated" shielded version). Last time I buy a part from Ford parts counter when an aftermarket lifetime warranty option exists for much cheaper.

EDIT: The 171 and 174 codes were coincidental. MAF went bad as well.