23rd Mar 2012, 20:45

Check your fuses and wiring. Possibly a TCM fuse is blown, Transmission Control Module. Maybe the wires that go from the transmission have rubbed and arced out. Have you scanned the vehicle with a code reader? If you do, write down codes before clearing, and when you clear codes and drive, then scan and diagnose from the first code that comes back. Good luck.

8th Mar 2015, 20:29

It is a neutral safety switch or NSS module that controls the shifting.