Experiencing issues with your 2018 Nissan Altima key fob? It’s a common frustration, especially after replacing the battery. You might find yourself facing problems like an “Invalid Key ID” message or unresponsive door request buttons, even though the remote lock/unlock functions still seem to work. Alternatively, you might encounter a situation where only the basic key functions operate, but the remote features like door lock, trunk release, or panic button are completely dead. Don’t worry, as a seasoned auto repair expert at keyfobprog.com, I’ve encountered these Nissan key fob issues numerous times and can guide you through some straightforward solutions.
Issue #1: “Invalid Key ID” or “No Key Detected” After Battery Replacement
This is a frequent problem after a key fob battery change on 2018 Nissan Altimas. The symptoms are usually quite specific: after replacing the battery, your dashboard displays “Invalid Key ID” or “No Key Detected.” The door request buttons on your car handles also stop working. Interestingly, the buttons on your key fob itself, for remotely locking or unlocking the doors, often continue to function. You can even start your Altima by physically pressing the start button with the key fob, or by using the emergency key fob receptacle if your model has one.
Solution: The good news is that you can often resolve this issue yourself with a simple key fob re-synchronization procedure. Here’s how:
- Remove the backup door key from your Nissan key fob.
- Enter your 2018 Nissan Altima and stay inside the vehicle with the key fob.
- Press the start button twice without pressing the brake pedal. This will cycle the ignition from OFF to ACC to ON.
- Exit the car, leaving the key fob inside. Make sure you take the backup door key with you.
- Close the driver’s side door.
- Insert the backup door key into the driver’s side door lock.
- Turn the key to the left (counter-clockwise) to lock the door. You should hear the door locking mechanism engage.
- Turn the key to the right (clockwise) to unlock the door. Again, listen for the unlocking mechanism.
- Remove the door key 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” messages should disappear, and all key fob functions, including door request buttons, should be working correctly again.
Issue #2: Remote Key Fob Buttons Not Working (Lock, Unlock, Trunk, Panic)
In contrast to the first issue, you might experience a scenario where everything seems normal except for the remote button functions on your 2018 Nissan Altima key fob. In this case, the push-button features like remote door lock, unlock, panic button, and remote trunk release (if equipped) become unresponsive. However, the key fob is still recognized by the car for starting and potentially door request (depending on the specific problem).
Solution: This problem often indicates that the key fob’s remote functions need to be re-established with your car’s computer system (ECU – Engine Control Unit). A simple ECU reboot with the key fob inside the vehicle can usually rectify this. During a cold boot (complete power down and restart) of the ECU, the push-button functionalities of the key fob are often reprogrammed if the key fob is present inside the car.
The easiest way to perform a cold reboot of your Altima’s ECU is to disconnect the main car battery:
- Locate the main car battery under the hood of your 2018 Nissan Altima.
- Using a wrench, disconnect the negative battery terminal. Typically, this is the black cable, and it’s often marked with a ‘-‘ sign.
- Wait for a minute or two. This allows the ECU to fully discharge and reset.
- Reconnect the negative battery terminal securely.
Important Note: Disconnecting your 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. This is normal, and the car’s computer will quickly relearn and return to its optimal operating settings.
Preventative Measures and Additional Tips
To minimize key fob issues with your 2018 Nissan Altima, especially after battery changes, consider these tips:
- Replace the battery before it completely dies: Intermittent key fob problems can sometimes start when the battery voltage gets very low. Replacing the battery proactively can prevent memory corruption in the key fob.
- Use the correct battery type: The recommended replacement battery for your Nissan key fob is a CR2032 button cell. While a CR2025 will fit and function in an emergency, it is slightly thinner and has a lower capacity, meaning it won’t last as long as a CR2032.
- Reprogramming both key fobs: If you have two key fobs for your 2018 Nissan Altima and are experiencing issues with both, you can try performing either of the above procedures with both key fobs inside the car simultaneously. While I haven’t personally verified this, it’s reported to work and could save you time.
By following these troubleshooting steps, you should be able to resolve most common “2018 Nissan Altima Key Fob Not Working” issues yourself. However, if you continue to experience problems, it’s always best to consult a professional automotive technician or your local Nissan dealership for further diagnosis and repair.
