# P1644 on the 2018 Peterbilt 520

The bulletins listed name this code in NHTSA's summary, or are about the same components. A bulletin or a recall listed here may apply to the model year. None of it is a diagnosis.

This code is specific to a manufacturer and is not described here.

## Bulletins for this model year that name P1644

- [10159673](https://open.wenmarpro.com/bulletins/10159673), 2019-05-13: Non Safety Campaign: Vehicles were built with a 5 bolt supply wire for the air dryer pressure sensor that is no longer required with current architecture. If left in place, a fault code P1644 may be set.