LifestyleMaintenance Tips

Car Won’t Shift Out of Park?

Learn how to fix and understand the causes

Have you ever attempted to leave for work in the morning, only to find that your automatic transmission Won’t Shift Out of Park? If so, you are certainly not alone. While indeed troubling, this issue is far more common than one might think.

Luckily, when a transmission is stuck in park, a minor mechanical fault is often to blame. Such an issue seldom requires extensive mechanical intervention or heavy repair to remedy. With a little prior knowledge and a few minutes worth of impromptu diagnostics, the root cause of this concern can be uncovered.

Read on to learn more about why your transmission is stuck in park, and what will be required to fix this condition.

Understanding Transmission “Park” Operation

Throughout the years, automotive manufacturers have made great strides toward increasing vehicle safety. As a result, automatic transmissions have been engineered to feature a number of fail-safe features, which prevent a vehicle from moving, other than when intended. 

All automatic transmissions now rely upon a device called a parking pawl, to prevent unintended vehicle movement when in the “park” position. When a vehicle is placed in park, this lever-like device engages a specialized parking gear, which is mated to the transmission’s output shaft. The parking pawl disengages from this parking gear when any alternative shifter selection is made.

Potential Causes of a Stuck In Park Condition

The following are the most likely causes of a vehicle’s transmission failure to release from its park position.

Ø  Incline Induced Pawl Pressure

When parking on a steep incline, a transmission’s parking pawl can come under an immense amount of pressure, as it wedges into its corresponding parking gear.

Under these circumstances, the parking pawl and parking gear are supporting a vehicle’s entire weight. This often makes it difficult to shift out of the park position, leaving motorists stranded in the process.

In this case, one must relieve this pressure, in order to successfully shift into any drive gear. This often requires the help of a second individual, who can create enough movement to facilitate proper disengagement, by rocking the vehicle back and forth.

However, on steep inclines, this process might require the use of a secondary towing vehicle.

In order to prevent such a situation, it is imperative to set your parking brake when attempting to stop on an incline, prior to placing your vehicle in park. This places all weight on a vehicle’s parking brake assemblies, as opposed to the parking pawl and parking gear.

Ø  Shifter Interlock

To prevent a vehicle from being accidentally shifted into drive or reverse, engineers typically fit all vehicles with a shifter interlock system. This interlock manually bars a shifter from being moved out of the park position, until the vehicle’s brake pedal is depressed.

However, interlock systems do fail in the engaged position on occasion. To prevent motorists from becoming stranded under such circumstances, the majority of manufacturers fit their vehicles with a shift lock release. The use of this release allows a driver to override their vehicle’s shifter interlock.

The shifter interlock in some vehicles can be bypassed by simply turning your key to the accessory position, and placing the shifter in the neutral position, where the vehicle can then be started.

However, if this proves ineffective, one can access the manual shift lock override, which is typically engaged by inserting a key or small flathead screwdriver. 

The location of this manual override differs from one vehicle to the next, though one can consult their owner’s manual for specifics. It is a wise idea to familiarize yourself with such procedures now, rather than to be forced to seek such information out when in the midst of a park related issue.

Ø  Brake Switch Failure

As previously mentioned, most vehicles feature a shifter interlock that is reliant upon brake pedal operation for disengagement. This system detects brake pedal operation through the actuation of a brake switch.

If this switch fails, the interlock function can be adversely affected. Typically, a vehicle’s shift interlock will act as if the brake pedal was never applied.

The simplest way to diagnose such an issue is to have a helper monitor your vehicle’s brake light operation. If your brake lights fail to illuminate when you depress the brake pedal, your vehicle’s brake switch is likely faulty. This is a presumptive diagnosis, which can later be verified through testing with a multimeter. 

If your vehicle’s brake switch does indeed prove to be faulty, replacement will be necessary in order to prevent the recurrence of this issue.

In many cases, this is a relatively simple job to complete, and requires little to no expenditure outside of the purchase of a replacement sensor. Replacement brake sensors can typically be sourced from any local parts distributor.

How To Release A Shifter Stuck In Park

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.

Problems from parking on an incline

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.

Never try to force the shifter

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.

The brake/shifter interlock

Accidently shifting a running vehicle into reverse or drive could be devastating. Over the years many people have been injured and property damaged by this exact occurrence. The brake-shift interlock is designed to prevent the vehicle from being shifted out of park, without the brakes being applied.

Engineers have designed many different systems, but they all require brake applications 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.

Finding the release procedure

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.

Ford column shifter

If turning the key to the first position does not work, there are normally other methods.  Check carefully around the steering column for an opening. Some Ford column shift vehicles have a slot, under the column. Pushing a key or a screwdriver into the slot releases the brake-shift interlock.  Apply the brakes and push on the release.  The vehicle should shift out of park.

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