Having similar issues as of early this morning. However, my truck only seems to have problems shifting from park to drive. I am gonna look at the brake switch and shift lock/release solenoid as suggested. Seems to be intermit. About 1 out of every 4-5 cycles I can not hear the lock/release solenoid engage/disengage in the shift lever immediately upon applying pressure to the brake peddle, at which point I have to cycle the ignition switch off/on to get it unlock. On a couple of occasions, I heard the solenoid click multiple times once I shifted to drive. At this point, I am I am leaning towards the solenoid verses the brake switch. Any thoughts? Also, does anyone have the part numbers for the brake switch and shift solenoid and where might be the best place to source them from...as always, thank you in advance for any/all help.