When the car selector lever for automatic transmission is in “P” position the car won’t hold and have a tendency to move.
Car Problem Diagnosis
Problem of car with automatic transmission that won’t hold even when the selector lever is in “P” position is often cause by an out of adjustment linkage. Transmission internal component and the gear selector is connected by a linkage, when this linkage is out of adjustments the automatic transmission will not be in “P” position even if it shows that the lever is correctly positioned, thus the car won’t hold.
Another cause of a car not holding at “P” position is by having bad parking lock pawl. The parking lock pawl is the one that helps to keep the car stationary when the gear selector is in “P” position. When this part is faulty the car will move even when the gear selector is in “P” position.
Possible Cause of Transmission Problem
Bad parking lock pawl or out of adjustment linkage.
All about car Recommendation
The only option that you have is to bring the car to a reputable auto repair shops specialized in automatic transmission and ask the mechanic to check the gear selector linkage and the parking lock pawl then repair if necessary. As for the meantime use the parking brake to keep the car from moving while the car is in stationary to avoid accident that may cause due to your car that won’t hold in “P” position.