Car Won't Fully Shift into Park

Does the car have floor shift or column ?
Ignition Key Cannot Be Removed from the Ignition Lock Cylinder (Column Shift)
Ignition Key Cannot Be Removed from the Ignition Lock Cylinder (Floor Shift)

Ignition Key Cannot Be Removed from the Ignition Lock Cylinder (Column Shift)
Step
Action
Yes
No
1
Did you review the Steering Wheel and Column Description and Operation and perform the necessary inspection?
YES - Go to Step 2
NO - Go to Steering Wheel and Column Description and Operation
2
Verify the key cannot be removed from the ignition lock cylinder.
Is the key stuck in the lock cylinder?
Go to Step 3
System OK
3
Is the vehicle equipped with a manual transmission?
Go to Step 7
Go to Step 4
4
Turn the ignition key to the OFF position.
Can the key be turned to the OFF position and be removed?
Go to Step 7
Go to Step 5
5
Verify the adjustment of the automatic transmission cable. Refer to Range Selector Lever Cable Adjustment .
Can the key be turned to the OFF position?
System OK
Go to Step 6
6
Inspect the linear shift assembly and cable for damage.
Is the linear shift assembly or cable damaged?
Go to Step 9
Go to Step 7
7
Inspect for a faulty lock cylinder.
Is the lock cylinder damaged?
Go to Step 10
Go to Step 8
8
Inspect the ignition lock cylinder case.
Is the worn, damaged, or loose?
Go to Step 11
Go to Step 12
9
Replace the linear shift assembly. Refer to Linear Shift Assembly Replacement .
Did you complete the repair?
Go to Step 12
--
10
Replace the ignition lock cylinder. Refer to Ignition Lock Cylinder Replacement .
Did you complete the repair?
Go to Step 12
--
11
Replace the ignition lock cylinder case housing. Refer to Ignition Lock Cylinder Case Replacement .
Did you complete the repair?
Go to Step 12
--
12
Operate the system to verify the repair.
Did you correct the condition?
System OK
Go to Step 2

What make vehicle ? Most all vehicles have a safety system .Don't try an force anything you'll break it !
Electronic Park Lock (EPL)/Ignition Lock Cylinder Control Actuator: If the vehicle is equipped with automatic transmission and a floor mounted console gear shift, it has an ignition lock cylinder control actuator system in the steering column. The ignition lock cylinder control actuator purpose is to prevent the ignition key from being turned to the OFF position when the transmission is in any position other than PARK and the vehicle may still be moving. The column ignition lock system consists of an ignition lock cylinder control actuator, and a park position switch that is located in the automatic transmission shift lock control switch. The ignition lock cylinder control actuator contains a pin that is spring loaded to mechanically prevent the ignition key cylinder from being turned to the lock position when the vehicle transmission is not in the PARK position. If vehicle power is lost, and/or the transmission is not in the PARK position the operator will not be able to turn the ignition key to the lock position and will not be able to remove the ignition key from the column. They also have this on column mounted shifters !

hello, check your terminals on the switch wire connector, there is a yellow wire that terminal might be loose.

Check the mechanism inside the gear lever thumb button in case it has failed.

Gear shift is not totally in the park position - had the same problem with a 2011 Acura TL - a rubber band kept the gear shift lever from totally seating in the park position.

If you cannot move the gearshift lever out of P (Park) with ignition in
the RUN position and the brake pedal depressed:
1. Apply the parking brake, turn ignition key to LOCK, then remove the
key.
2. Insert the key and turn it to OFF. Apply the brake pedal and shift to N
(Neutral). This allows the automatic transmission shift lever to be
moved from the P (Park) position without the brake pedal
depressed.
3. Start the vehicle.
If it is necessary to use the above procedure to move the gearshift lever,
it is possible that a fuse has blown or the vehicle's brakelamps are not
operating properly.

Most newer models have a safety feature called
shift interlock. This prevents the key from being turned back
to the lock position if you forget to place the gear selector in park.
Depending on the model,
If it uses a cable, it may be sticking or needs adjusting.
If it uses an electrical solenoid. may be blown fuse or park switch.
Tap, shake, and pull up on the shifter and make sure it's in park.

Sounds as if the ignition cylinder is bad. You will have to replace it if the key is stuck. It is a lot easier to replace with the key in the on position as that will be required to remove the cylinder. If you get the key out and then the cylinder will not turn, replacement of the cylinder will be more complicated

Ignition - Key Stuck In Ignition Switch/Won't Turn Bulletin No.: 06-02-35-005 Date: February 28, 2006 TECHNICAL Subject: Key Stuck in Ignition, Key Will Not Return to Off Position, Shifter Button Won't Release in Park Position (Adjust Shifter Detent Finger) Models: 2002-2005 Chevrolet Monte Carlo Condition Customers may comment on any of the following conditions: - The key is stuck in the ignition cylinder. - They cannot return the key to the off position to remove the key. - The shifter button won't release in the park position. Cause This condition may be caused by the detent finger shifting over time. This may result in mis-alignment and binding of the shift rod on the shift position guide.
WHERE YOUR SHIFTER IS YOU WILL HAVE TO TAKE IT APART ..MAYBE THE RUBBER BOOT IS IT THE WAY,OR THE SHIFT LOCK SELINOID WHENT BAD

The car is probably on a steep hill and a lot of pressure is on the park pawl in the automatic transmission. If this is the case, a hard sudden pull should release it. Make sure the brake is on. When parking on a hill in the future use the parking brake before placing the lever in park.