One problem related to automatic transmission park/neutral start switch has been reported for the 1999 Chevrolet Tahoe. The most recently reported issues are listed below.
Transmission stuck in 3rd gear. Upon dealer diagnosis they found transmission harness chafed within the transmission housing. This component is not exposed to outside elements. Because it is wiring with no exposure, the insulation on the wire should not deteriorate unless subjected to extreme high temperatures or rubbing.