It might come as a surprise, but your 2015 Jeep Grand Cherokee key fob is engineered to start your vehicle even when the remote battery is dead. Many drivers are unaware of this feature and the clever technology behind it. The key fob is more than just a remote for locking and unlocking your doors; it’s a sophisticated piece of equipment with multiple layers of functionality. Let’s delve into how your key fob operates, especially when that little battery icon on your dashboard starts flashing or, worse, when your remote functions cease to work entirely.
Your 2015 Jeep Grand Cherokee key fob actually incorporates two, or even three, systems in one. For basic models, you have two core systems. Firstly, there’s the familiar remote control system that requires battery power to transmit signals to your vehicle for actions like locking, unlocking, and remote start (if equipped). This is the function that stops working when your key fob battery dies. Secondly, and crucially for starting your car when the battery is dead, there’s a transponder or RFID (Radio-Frequency Identification) chip. This RFID chip is passive, meaning it doesn’t need battery power from the key fob itself to operate.
Alt text: Close-up of a 2015 Jeep Grand Cherokee key fob highlighting its physical key insert and button layout, emphasizing the design for both remote and proximity functions.
How does this battery-less system work? Inside your Jeep Grand Cherokee’s ignition system, near where you would insert a traditional key or around the push-to-start button, there’s an antenna. This antenna emits an RF (radio frequency) signal. When you bring the key fob close to the ignition, the RF energy from this antenna energizes the RFID chip in your key fob. This energy allows the chip to communicate with your car, authenticating the key and allowing you to start the engine. This ingenious design is why you can still start your 2015 Jeep Grand Cherokee even with a completely dead key fob battery. The battery is only needed for the remote functions, not for the essential task of starting your vehicle.
For models equipped with proximity enter and go, there’s a slightly more advanced, almost 2.5 system setup. Proximity key fobs allow for keyless entry and start without physically pressing buttons on the fob (beyond the start button in the car). These systems need to broadcast the RFID signal over a greater distance – several feet – for the car to detect the key as you approach. This extended range capability typically requires an additional RF component within the key fob that does need battery power. If you were to compare the circuit boards of a standard key fob and a proximity key fob, you’d notice the proximity version is more complex, often featuring a larger, shielded RF chip to handle this extended communication range.
So, how do you actually start your 2015 Jeep Grand Cherokee when your key fob battery is dead? For older systems, you might have a physical key insert within your key fob. You would pop out the push-button start (if applicable) and insert the key head of the fob, starting it much like an old-fashioned key start. In the more common newer system found in the 2015 Grand Cherokee, the process is slightly different and perhaps less intuitive. The RFID chip in these newer fobs is typically located in the bottom center of the fob (opposite end from the key insert, if present). To start your vehicle, you need to press the bottom end of the key fob directly against the push-to-start button. Then, while holding it there, press the start button as you normally would.
Alt text: Demonstrating how to start a 2015 Jeep Grand Cherokee with a key fob that has a dead battery, by pressing the end of the fob against the push-to-start ignition button.
This action places the RFID chip close enough to the ignition switch antenna to be energized and communicate the necessary security code, allowing your 2015 Jeep Grand Cherokee to start. It’s important to remember that while the key fob battery might be dead, your car’s battery needs to be in good working order and have sufficient voltage to energize the RFID chip reader in the ignition system. A completely dead car battery will prevent the RFID system from working, even with a good key fob. You might even see an “invalid key” message on your dashboard display if the car battery is too weak to properly power the system.
In conclusion, understanding the dual nature of your 2015 Jeep Grand Cherokee key fob – the battery-powered remote and the battery-independent RFID chip – is crucial. Knowing how to start your vehicle with a dead key fob battery can save you from being stranded. While this article explains how to start your car in an emergency, don’t forget the importance of regular key fob battery replacement to ensure all remote functions continue to operate reliably. Consult your owner’s manual for specific instructions on battery replacement and further details on your 2015 Jeep Grand Cherokee’s key fob system.
