What Is a Transmitter Pocket? (Plus FAQs)

Vehicles have come a long way since steam power and carburetors were introduced.

Today, there are millions of electric vehicles taking over the highways and other cars that are capable of autonomous driving, which are only some of the numerous innovations automakers have developed.

But perhaps one of the most convenient features many drivers have come to enjoy is keyless ignition.

Keyless ignition systems might vary depending on the vehicle manufacturer, but a lot of them share a couple of similarities, including a transmitter pocket.

A Closer Look at the Transmitter Pocket

A transmitter pocket is more than a storage compartment for your vehicle’s key fob. Placing the key fob in the pocket lets you start the engine or leave it idling while you’re away.

Like many remote keyless ignition systems, the key fob sends a coded, verifiable radio signal to the vehicle’s computer system. Once it’s been verified that the correct key is used, the driver be able to start the engine and perform other keyless tasks.

Keyless ignition systems have been around longer than you think. They debuted in the market sometime between the late 1990s and early 2000s.

Back then, keyless ignition was a luxury feature in high-end models like the Mercedes-Benz S-Class, Acura, Cadillac, Lexus, and Rolls-Royce.

A few years after the tech’s debut, it became a standard feature in 11% of the vehicles sold in the US in 2008. This number went up to 62% by 2018.

Where Is the Transmitter Pocket Located?

The location of the transmitter pocket will depend on the vehicle’s specifications.

Some vehicles have it built into the center console’s front panel or near the cupholder on the driver’s side. Most vehicles with a transmitter pocket also have a backup compartment.

Can You Use the Transmitter Pocket to Start Your Vehicle?

Absolutely. The transmitter pocket is one way to start your vehicle in case the key fob gets damaged or its battery runs out of juice. Even with a dead key fob, the pocket can still pick up the necessary radio signals to start the engine.

Keep in mind, however, that the transmitter pocket doesn’t serve as a charging port for a dead key fob. You’ll still need to replace its battery or buy a new fob.

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: If the key fob is not working due to possibly a low battery, you can try using the key fob to push the start button on the engine start. This has actually helped start a lot of vehicles that would not start otherwise.

Will a New Key Fob Affect the Transmitter Pocket’s Operation?

Yes. In most cases, the pocket transmitter is configured to the original key fob, so buying a replacement means you’ll need to program it to the transmitter.

There are several ways to configure a replacement key fob, but the right one will depend on your vehicle’s specifications.

Some models also acknowledge up to eight verified key fobs for a single vehicle. So if you’re planning to keep a spare fob around in case of emergencies, you might want to configure an extra one.

Keyless Ignition Systems and Everything In Between

Transmitter pockets are one of the many convenient features of keyless ignition systems.

Because of this technology, many drivers only need to push a button to start the engine and get on with their daily driving duties.

But aside from offering a hassle-free driving experience, keyless ignition systems also aim to increase vehicle security and safety.

For example, vehicles with a keyless ignition system won’t start unless the gear is in park and the driver’s foot is on the brake pedal.

As for security, this system relies on specific signals from a key fob to open the vehicle, which prevents thieves from breaking in using lock picks and other devices.

The Problem With Keyless Ignition Systems

As convenient as they are, keyless ignition systems also come with a few cons.

First, although thieves will have a hard time breaking into keyless vehicles, they’ll still be able to succeed with the right equipment.

Keyless car theft involves using a relay amplifier and relay transmitter. Thieves use the amplifier to pick up the key fob’s signal if it’s close to the vehicle. Once the receiver picks up this signal, the vehicle’s computer will be tricked into verifying a replica of the key fob’s code.

There have also been several reports of carbon monoxide poisoning because drivers forgot to shut off their engines.

A quiet engine paired with keyless ignition also resulted in many vehicles lurching forward because drivers forgot to shift into park. This is a common occurrence in many vehicles that have ignition keys as well. 

To deal with this problem, many automakers programmed specific models to trigger an audible alarm whenever the ignition is left in the accessory position and the driver isn’t around.

Preventive Measures

Keyless ignition systems aren’t exactly infallible, which means they’re also at risk of compromising your safety and security if you don’t know how to work with them.

Vehicle manufacturers are also aware of this, and many have come up with several ways to combat keyless theft.

For example, automakers like BMW, Audi, Ford, and Mercedes provided their keyless ignition models with motion-fitted sensors that deactivate the key fob’s signal when it’s resting.

Jaguar and Land Rover, on the other hand, use ultra wide-band radio technology to prevent thieves from isolating their vehicle’s signals.

As a car owner, there are also some things you can do to minimize the risks of having a keyless ignition system.

The simplest would be to keep your key fob away from your vehicle when it’s not being used. This makes it harder for thieves to detect the fob’s signal.

You can also keep your key fob in a Faraday pouch, which is designed to block electromagnetic signals. Some manufacturers include this accessory upon purchasing their vehicles, but you can also buy one yourself.

The Bottomline

Transmitter pockets are compartments specifically designed for key fobs. If the key fob’s battery runs out of juice, you can still start the engine if the fob is in the pocket.

The location of the transmitter pocket largely depends on your vehicle’s specifications, but several manufacturers have it built into the center console or near the cupholder on the driver’s side.

Lastly, replacing the original key fob will also require you to configure the new one. To do so usually requires special tools, scan tools or a locksmith to program the key fob.