Hey everybody, I got this issue with my 2006 F-150 where the 4x4 won't engage. Other than that runs fine. Troubleshooting everything from the vacuum lines to the t-case shift motor and only thing left is the PCM. Could just a small part of the ECU/PCM go out and cause just that problem?

 

The PCM controls the 4WD system so it's certainly possible.

I'd recommend exhausting all the procedures in the workshop manual pinpoint tests before condemning the PCM, though, as its replacement will put you into a shop to re-program the PATS system.

 

So it's not just a (plug and play)?

 

Nope. Hasn't been since 1998, last year for non-PATS, for the F150.