P051b code 2017 ford escape?

The P051B diagnostic trouble code (DTC) on Your 2017 Ford Escape means Crankcase Pressure Sensor Circuit Range/Performance. This error relates to the crankcase pressure sensor alerting the ECM to an error condition with... The crankcase pressure. Yes, exactly what it says. Basically, this is triggered if there's too high pressure, or too low (fuels not burning). In the latter case, it's just a fuel efficiency issue, but in the former, You could have damage to seals and gaskets. You'll see this error if there are values well outside the normal operating ranges for the circuit. You should also be aware there's a Technical Service Bulletin from Ford regarding this, TSB 19-2347, NHTSA ID Number: 10168763. The bulletin notes that some 2017 Ford Escapes equipped with the 1.5L EcoBoost engine may see this check engine light come on with this code due to the pressure sensor/tube assembly being subpar from the factory, and in need of replacement from the dealer.