Is your Nissan Altima key fob suddenly not working? It can be a frustrating experience, especially when you’re locked out of your car or unable to start it. As a car repair expert at keyfobprog.com, I’ve encountered two common issues with Nissan key fobs, particularly after a battery replacement, that can leave you with a seemingly unresponsive remote. Let’s dive into these problems and their solutions to get your Altima key fob working again.
Issue #1: “Invalid Key ID” or “No Key Detected” Messages After Battery Replacement
One common problem Altima owners face after replacing their key fob battery is the dreaded “Invalid Key ID” or “No Key Detected” message appearing on the dashboard. You might also notice that the door request buttons on your car no longer function. Interestingly, the key fob buttons for remote door lock/unlock and trunk release might still work, and you can typically start the engine by physically pressing the start button with the key fob or inserting it into the emergency start receptacle (if your model has one).
Here’s a step-by-step solution to resynchronize your key fob:
- Remove the mechanical backup key from your Nissan Altima key fob.
- Enter your Altima and keep the key fob inside the vehicle.
- 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, but take the backup door key with you.
- Close the driver’s side door and use the backup door key to manually lock the door by turning the key to the left in the door lock cylinder. You should hear the locking mechanism engage.
- Unlock the door immediately by turning the key to the right. Again, listen for the unlocking mechanism.
- Remove the door key and re-enter your Altima.
- Press the start button one more time (again, without pressing the brake) 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. This procedure effectively re-syncs the key fob with your Altima’s immobilizer system.
Issue #2: Key Fob Buttons Not Working (Remote Lock, Panic, Trunk Release)
In contrast to the first issue, you might encounter a situation where everything seems normal, except for the push-button functions on your Altima key fob. This means the remote door lock, panic button, remote trunk release, and remote start (if equipped) are unresponsive, even though the car starts and recognizes the key for driving.
The solution for this issue involves performing a cold reboot of your Altima’s ECU (Engine Control Unit) with the key fob inside the car. During this reboot process, the push-button functions of the key fob are reprogrammed if the key is present in the vehicle.
Here’s how to perform an ECU cold reboot:
- Locate the main car battery under the hood of your Nissan Altima.
- Disconnect the negative battery terminal. Use a wrench to loosen the nut on the negative terminal (usually marked with a “-” sign and a black cable). Carefully remove the cable from the terminal.
- Wait for a minute or two. This allows sufficient time for the ECU to fully discharge and reset.
- Reconnect the negative battery terminal. Place the cable back onto the negative battery terminal and tighten the nut securely.
After reconnecting the battery, your Altima’s ECU will reboot. Start your car and test the push-button functions on your key fob. They should now be functioning normally. Be aware that disconnecting the battery can temporarily reset the ECU’s learned settings, which might cause a slightly different idle for the first few miles of driving. This is normal, and the car will quickly readjust.
General Tips and Key Fob Battery Information
To prevent these issues, consider replacing your Altima key fob battery proactively before it gets too weak and potentially corrupts the key fob’s memory. The correct replacement battery is a CR2032 button cell battery. While a CR2025 battery (slightly thinner with slightly lower capacity) can work in an emergency, it’s recommended to use the CR2032 for optimal performance and battery life.
It’s also reported that you can reprogram both key fobs at once by leaving them both inside the car when performing either of the procedures described above. While I haven’t personally verified this with two fobs simultaneously, it’s worth trying if you have multiple key fobs experiencing issues.
By following these troubleshooting steps, you should be able to resolve most common “Altima Key Fob Not Working” problems yourself. If these solutions don’t work, there might be a more complex issue, and it’s advisable to consult with a qualified automotive technician or your Nissan dealership.
