Shift Lock Release Button in Automatic Transmissions

It is well-known that modern automatic transmissions are much more complex than conventional manual transmissions, and therefore in addition to standard driving modes like D (Drive) and R (Reverse) automatics frequently have more additional features and operating modes.

Owners of automatic cars frequently cannot fully control the operation of complex automatic transmissions, thus manufacturers have to develop special features, which will help drivers to handle different situations on the road. In this article, we will consider a Shift Lock Release (or simply Shift Lock) button that frequently raises a lot of questions among young drivers.

Automatic transmission technologies never standing still

Nowadays, automatics are equipped with complex control systems and have many different modes of operation depending on specific operation conditions and it seems like automotive engineers are not going to stop there. Automatic transmissions and their control modules are constantly upgraded, more and more electronic components are integrated in their designs, thereby strengthening positions of automatics on the world market. But the excessive use of electronics has its drawbacks. Different microcircuits, sensors and board components, wiring and other elements frequently fail because of vibrations, moisture, overheating, etc. To adjust the performance of the gear shifting unit to the liking of drivers or to the road conditions, engineers came up with additional modes that help to deal with different situations on the road and reduce load on the gearbox.

In addition to the main modes (P-R-N-D), automatics frequently have the capacity to lock the upshifting (when the gearbox cannot shift higher than 2nd gear or constantly operates on 1-st gear). There are modes that allow the driver to decide when the gear shifting should take place, namely Overdrive and Tiptronic. Overdrive mode allows the driver to put in the highest gear. Tiptronic mode is implemented by moving the shift lever into a second operating plane of the shift gate marked with symbols “+” for upshifting and “-“ for downshifting, thereby allowing drivers to decide what gear should be engaged.

That’s how Tiptronic is implemented in automatic transmissions

Moreover, owners of automatic cars also can notice other buttons, including winter mode (marked with a snowflake mark or named as ECT SNOW), economy mode, or sports mode. But some automatics also have a mysterious “Shift Lock Release” button.

The purpose of various buttons mentioned above is more or less clear on an intuitive level. For instance, it is quite simple to guess the meaning of the button ECT SNOW/*- it actuates winter mode, i.e. the car starts moving from 2-nd gear to prevent slippages on snow or ice. When this mode is actuated, the behavior of the car gives a clear hint at its purpose. But when we are talking about a Shift Lock button, it is not that simple. The point is that nothing changes when this button is pressed, or rather the driver notices no changes in the transmission operation.

As a rule, the Shift Lock button is placed close to the gear lever (commonly next to P gear). When you this button is pressed the transmission continues normal operation, the RPM rate of the engine doesn’t change, gears shift smoothly, and there won’t be any special icons highlighted on the dashboard. So what’s that? A trick from manufacturers? No, some drivers may not even need to use this button for years, but in some situations it can be extremely helpful.

Why actually automatics are equipped with a Shift Lock Release button?

First of all, it should be noted that unlike Tiptronic or Overdrive, Shift Lock is not some special driving mode and does not affect the gearbox operation. In fact, this button allows you to forcefully remove the lock when the transmission is in P mode and to put the gearbox in some other gear, if the car engine is turned off.

Owners of automatic cars should know well that the shaft lock inside that transmission becomes actuated, when the selector is put in P gear. After that, it is impossible to move the lever without pressing the brake pedal or without inserting the key into the ignition switch (different brands implement this algorithm in various manners).

Learn how to use shift lock release for double parking

That’s where Shift Lock can come in handy, as this button allows unlocking the transmission gear shaft and put the lever in N position, when the engine does not start or the gearbox fails, and it is needed to start towing the car. Thus, it may be concluded that the Shift Lock button is intended for unlocking the transmission (out in P position), if your car happens to be involved in a road accident or the transmission unit gets out of order.

This button can also be useful during maintenance services of automatic cars. If the gear shifting mechanism gets out of order, technicians from repair shops can shift gears with the use of Shift Lock.

In some cars, the Shift Lock technology is implemented not by means of a special button, but by a key hole also located near the gear lever. In fact, this key hole is actually an analog of a button. In this case, to unlock the transmission, it is needed to insert the ignition key in the key hole mentioned above.

Learn how to use Shift Lock mechanism properly

Summary

Even taking into account technical superiority and reliability of modern automatic cars, it is impossible to rule out the possibility of road accidents, transmission malfunctions, or gear lever locking. In these cases, it may be necessary to unlock the lever and the Shift Lock button (or its key-hole analog) solves this problem. It is also important to remember that it is recommended to keep the brake pedal pressed, when you shift from P to N with the use of Shift Lock. It will help to exclude any uncontrolled movement of the vehicle. Even if the car stands on a flat surface without any inclinations, for safety reasons, it is better to press the brake pedal when using the Shift Lock button.

In conclusion, it should be noted that before intensive usage of a new automatic car, it is desired to become familiar with all functions, buttons (Shift Lock in particular) and modes of the gearbox (described in detail in the manual) to enjoy its benefits to the fullest.