Most modern vehicles will not shift out of the park position, unless we apply the brakes. This is a safety feature.  The feature may go unnoticed, until the vehicle will not come out of park, even with the brakes applied. In the past, they equipped most vehicles with a manual transmission. When parking a manual transmission vehicle, we place the shifter in reverse. Because the gears in this transmission physically engage each other, this keeps the vehicle from rolling.

Today they equip most vehicles with an automatic transmission. With an automatic transmission, fluid pressure applies the gears. When the engine is not running, pressure drops to zero. Without the engine running, an automatic transmission turns freely, though it may be in gear. To solve the problem, engineers use a parking mechanism.

When we shift into park position, the parking pawl engages a parking gear. They attach this parking gear to the output shaft of the transmission. This physically locks the output shaft to the case of the transmission and prevents the vehicle from rolling. Selecting any gear, other than the park position, releases the mechanism.

The park system is simple and robust, but problems can occur. One such problem is a shifter that will not come out of the park position. The most common cause is the brake/shift interlock, discussed in the next section. Another cause is too much force applied by the park gear.

Parking on an incline may cause our shifter to stick in the park position. If we release our brakes, after we shift into park position, the vehicle may roll. This places the weight of the vehicle on the parking gear and pawl. With too much load on the system, we cannot shift from the park position.

When parking on an incline, we first firmly apply the parking brake. Before shifting to park, we take our foot off the brake pedal and make sure the vehicle does not roll. With the vehicle weight held by the parking brake, we shift into the park position. With this method, the parking brake holds the weight of the vehicle and not the park pawl and gear. We can easily move our shifter out of park position.

If the shifter will not come out of park position, due to the vehicle rolling, we need to push it slightly, to relieve the pressure. Moving the vehicle uphill takes the weight off the transmission. If the incline is slight, we may move it by hand. Be sure to apply the brakes firmly, before taking it out of the park position. On larger inclines, we may need a wrecker or push-vehicle. Only a few inches will normally relieve the pressure.

We should never try to force the shifter to move, when it sticks in park position.  If normal effort does not move the shifter from the park position, pulling with more force will not help and will likely break something.  Most shift mechanisms use a cable to connect to the transmission. They construct shifter cables and mechanisms of light materials. Any excessive force will break the cable or damage the shifter. If the shifter cable breaks, changing gears is not possible. Repair involves towing the vehicle and replacement of the shifter components.

Engineers have designed many different systems, but they all require brake application to release the shifter from the park position. Most systems use a magnetic solenoid or an actuator that blocks the path of the shifter. Applying the brakes sends a signal to the mechanism which releases the shifter. Things sometimes go wrong and the vehicle may not allow the shifter to move from the park position.

Examples of problems include the mechanism failing in the locked position and the brake light switch not sending the signal. Such failures keep the shifter from moving out of the park position.

Because failure will strand the driver, they usually provide means to override the system. The override feature allows the driver to release the shifter in an emergency. Each vehicle uses a different procedure making it difficult to remember how they all work.

Fortunately, they will normally outline the procedure in the owner’s manual. Finding this information and practicing the procedure, before the need arises, is a wise precaution. In an emergency, attempting to find this information will be far more difficult.

With many column-mounted shifters turning the key to the first position after lock may allow overriding the system. The key must stop in position one. Turning the key all the way to on position will lock the shifter. Normally in the first position the dash will not light up, but the shift indicator may be on.

With the key in this position, apply the brakes and shift the vehicle to neutral. In neutral the vehicle will start and we can shift to drive or reverse. This allows the vehicle to override the shift-lock, but it may again lock when shifted back to park.

They place the access plugs in various locations, depending on the vehicle. Many are above, to one side or even below the shifter. The plug may also be found on the side of the shifter plate, on a few models. On other vehicles we pull the shifter bezel from the console and the release is below the cover, on the side of the shifter. 

A little time spent learning where the brake-shift interlock override is and how it works can prevent a great deal of trouble. If it cannot be found, check with your favorite mechanic. They will normally be happy to help.