UK Auto Repair Questions?
Can you check if your brake lights are working please?
If not replace the brake light switch, it is part of the circuit for the shift lock.
Ok, if the brake lights are working, the next cause is the BTSI (Brake Transmission Shift Interlock) solenoid.
Mounted on the gearshift mechanism.
We need to see if the 12v and ground is at the solenoid.
You should normally hear the solenoid operate in park while on and off the brake pedal.
Sounds like the BTSI solenoid I mentioned above.
I have replaced many of these.
Generally a job for a dealer tech.