Conditions Which May Cause a BLANK PRNDL
WARNING: This page is about a different car, the 2007 GMC Sierra and 2007 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The PRNDL display may be blank because of failure of the internal mode switch circuits A, B, C, or P.
The transmission will command the most appropriate range, based on reverse pressure switch and the remaining internal mode switch inputs.