It's happened twice now. I turn the car on and try to shift from Park to Reverse, but the button is locked and the shift won't move. Thankfully, I've been able to hold the override button next to the gear shifter which has allowed me to get the car out of Park. Why is this happening?

 

I have a 2003 RX300 and occasionally the shifter locks and I am unable to move the gear selector. Usually it will free up after a struggle.

Any ideas what may be causing this condition?

 

The shifter has a safety interlock and before it allows you to move out of "Park" the mechanism wants to make sure you that the brake pedal is depressed. So have some one ensure the brake lights are "on". If they don't light up then the problem is in the brake switch [on the foot brake pedal or fuse etc]. You can also experiment with the emergency release [plastic cover by the shifter, use a flat head to pop it off and there a relay that you have to press to release the interlock ... more info + pics in your owners manual]

Then there can be an issue with the shift release button.

The auto trans has a pawl which locks the transmission [does not allow the vehicle to roll when Parked]. This at times gets stuck and it mostly happens when Parking brake is not used and you park the vehicle on a slope.

Salim

 

I have had this happen about once a year for the last two years or so. I press the override, and wait another year until it happens again!
Next time it happens I will attempt to diagnose as per Salim's suggestion: https://www.clublexus.com/forums/rx-...ing-again.html