Experiencing problems with your 2018 Nissan Altima Key Fob can be frustrating. As your trusted auto repair experts at keyfobx.com, we understand these issues and are here to provide straightforward solutions. Many Nissan Altima owners encounter key fob malfunctions, especially after a battery replacement. This guide addresses two common scenarios and offers step-by-step instructions to get your key fob working again.
Issue #1: “Invalid Key ID” or “No Key Detected” Messages After Battery Replacement
One frequent complaint after replacing the battery in a 2018 Nissan Altima key fob is the appearance of “Invalid Key ID” or “No Key Detected” messages on the dashboard. Additionally, the door request buttons on your Altima may cease to function. Interestingly, the key fob buttons for remote locking/unlocking and trunk release often continue to work. You might also find that you can still start your Nissan Altima by physically pressing the start button with the key fob itself.
Solution: Re-syncing your key fob is often the answer. Here’s how to do it:
- First, remove the mechanical backup key from your 2018 Nissan Altima key fob.
- Enter your Nissan Altima, ensuring you leave the key fob inside the vehicle.
- Press the start button twice without pressing the brake pedal. This will cycle the ignition to the “ON” position without starting the engine.
- Exit the car, leaving the key fob inside. Make sure to take the backup door key with you.
- Close the driver’s side door and use the backup door key to manually lock the door. Turn the key to the left in the door lock to lock it. You should hear the locking mechanism engage.
- Immediately unlock the door using the same key, turning it to the right. Again, listen for the unlocking mechanism.
- Open the door and re-enter your Nissan Altima.
- Press the start button one more time (again, without pressing the brake pedal) to turn the ignition to the “OFF” mode.
After completing these steps, the “Invalid key ID” or “No Key Detected” messages should disappear, and all key fob functions, including door request buttons, should return to normal operation for your 2018 Nissan Altima.
Issue #2: Remote Key Fob Buttons Not Functioning
In contrast to the first issue, you might find that everything with your 2018 Nissan Altima key fob works perfectly fine except for the remote push-button functions. This means the remote door lock, panic button, remote trunk release, and remote start (if your Altima is equipped) are unresponsive.
Solution: A simple ECU reboot can often resolve this remote function problem. The Electronic Control Unit (ECU) is the car’s main computer. Rebooting it while the key fob is inside the car allows the system to re-establish communication with the key fob’s remote functions.
- The easiest way to perform a cold reboot of your Nissan Altima’s ECU is to disconnect the main battery located under the hood.
- Locate the negative terminal of your car battery and carefully disconnect the cable.
- Wait for a minute or two. This allows the ECU to fully discharge and reset.
- Reconnect the negative battery cable securely.
Keep in mind that disconnecting the car battery will reset the ECU’s learned settings. As a result, your 2018 Nissan Altima might idle or drive slightly differently for the first few miles after reconnecting the battery. However, the ECU will quickly relearn and adapt, and your car’s performance will return to normal. Crucially, your key fob’s remote functions should now be working correctly.
Key Fob Battery Replacement: Preventative Tips
To minimize the chances of encountering these key fob issues with your 2018 Nissan Altima, proactive battery maintenance is helpful. Replacing the key fob battery before it becomes critically low can prevent memory corruption within the key fob, which often leads to these problems in the first place.
The correct replacement battery for your 2018 Nissan Altima key fob is a CR2032 button cell battery. While a CR2025 battery, which is slightly thinner, can work temporarily, it’s best to use the CR2032. The CR2032 has a higher capacity and will provide a longer lifespan for your key fob.
Final Note: Some users have reported success in reprogramming both key fobs at once by leaving both inside the vehicle when performing either of the procedures described above. While we haven’t verified this ourselves, it’s worth trying if you have two key fobs experiencing issues.
By following these troubleshooting steps, you should be able to resolve most common key fob problems with your 2018 Nissan Altima. If issues persist, it’s always recommended to consult with a certified Nissan technician or your local key fob experts at keyfobx.com for further assistance.
