If it happens when your idling in park for like 5-8 minutes and it goes to Trans Fail and when you start it back off it goes away...that's what happened to mine 2002 ,it's the neutral safety switch.

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2002 X5 4.4i Sport Wheels
2014 X5 35i M Appearance & suspension package
1995 Porsche 993
1972 Porsche 914-6
2020 GLE 450 Twin Turbo
2019 Alfa Stelvio 500hp Quadrifogilo
Many motorcycles