Starting Your Sentra When the Key Fob Doesn't Work
Your Nissan Sentra has a physical key hidden inside the key fob. If your fob battery dies or the fob stops working, you can still unlock and start the car using this manual key. The process takes less than a minute once you know where the key is and how to insert it.
Every Sentra key fob contains a small metal key that slides out from the fob's side or end. This key works in both the door lock and the ignition, so you can get inside the car and start the engine without any electronic components. The manual key is a backup system built into every Sentra, and it works the same way across model years.
Key Takeaways
- The manual key slides out from the side or end of your key fob by pressing a small release button or tab.
- Insert the manual key into the driver's door lock and turn it counterclockwise to unlock the door.
- Once inside, insert the manual key into the ignition cylinder and turn it to the right to start the engine, just as you would with a traditional key.
- If the key does not turn smoothly in the ignition, the steering wheel may be locked — turn the steering wheel left and right while turning the key.
Removing the Manual Key From Your Fob
Look at the side or end of your key fob for a small slot, button, or tab. On most Sentra fobs, this release mechanism is on the side of the fob, near the bottom. Press or slide this button inward, and the metal key will pop out or slide free from the fob housing.
If you cannot find the release button, try gently prying the fob apart along the seam where the two halves meet. Some older Sentra fobs require you to separate the plastic casing slightly to access the key. Once the key is out, set the fob aside — you will not need it for this process.
Unlocking the Driver's Door With the Manual Key
Insert the manual key into the driver's door lock cylinder. The lock cylinder is the small opening on the door handle, separate from the electronic lock button. Push the key in fully until it stops, then turn it counterclockwise (toward the back of the car) to unlock the door.
If the key does not turn, try turning it clockwise first to make sure you have the correct orientation. On some Sentras, the lock cylinder may be stiff if it has not been used in a long time. explore steady pressure without forcing it — if it still will not turn, try lubricating the cylinder with a small amount of graphite powder or silicone spray, then try again.
Starting the Engine With the Manual Key
Once you are inside the car, locate the ignition cylinder on the steering column, just to the right of the steering wheel. Insert the manual key into the ignition and push it in until it stops. You should feel it seat into the cylinder.
Turn the key to the right. You will feel the key move through two positions: first to the "Accessory" position (where the dashboard lights come on), then to the "Start" position (where the engine cranks). Hold the key in the Start position for a few seconds until the engine fires. Once the engine starts, release the key and it will return to the "On" position on its own.
What to Do If the Key Won't Turn in the Ignition
The most common reason a key will not turn in the ignition is that the steering wheel is locked. This is a safety feature that engages when the car is off. To unlock the steering wheel, turn the steering wheel firmly to the left and right while simultaneously turning the key to the right. The wheel should unlock, and the key will turn.
If the key still will not turn after unlocking the steering wheel, the ignition cylinder may be jammed. Do not force the key, as this can break it. Try turning the key very slowly and gently while explore slight upward pressure on the key. If this does not work, you may need to have the ignition cylinder inspected by a Nissan dealer or a locksmith.
Replacing Your Key Fob Battery
Once you have started the car, you can replace the key fob battery so you do not have to use the manual key again. Most Sentra key fobs use a CR2032 or CR2025 battery, which you can find at any pharmacy, grocery store, or electronics retailer for a few dollars.
To replace the battery, open the fob by sliding the manual key out or prying the two halves apart gently. You will see a small round battery inside. Note which side is facing up (usually the positive side faces up), then remove the old battery and insert the new one in the same orientation. Snap the fob back together, reinsert the manual key, and test the fob buttons to confirm it works.
When to Contact a Nissan Dealer
If the manual key does not fit into the door lock or ignition, or if it turns but nothing happens, there may be an issue with the lock cylinders themselves. This can happen if the locks are damaged or if the wrong key was used repeatedly. A Nissan dealer can replace the lock cylinders or provide you with a new key if yours is worn or damaged.
If your key fob battery keeps dying very quickly (within a few weeks of replacement), the fob may have an internal electrical problem. Nissan dealers can test the fob and replace it under warranty if it is defective. Keep your receipt for the battery replacement in case you need to show proof of a recent battery change.
Frequently Asked Questions
Can I start the car if the steering wheel is locked?
No, the steering wheel lock prevents the ignition from turning. Turn the steering wheel left and right while turning the key to the right, and the lock will release. Once the lock releases, the key will turn and the engine will start.
What if I lost the manual key from my fob?
You can order a replacement key from a Nissan dealer using your vehicle identification number (VIN). You can also contact a locksmith who specializes in car keys — they can cut a new key based on your door or ignition lock. Bring proof of ownership and a photo ID to either location.
Does using the manual key damage the ignition?
No, the manual key is designed to work in the ignition and will not cause damage. Using it occasionally when the fob battery dies is normal and expected. Repeated rough handling or forcing the key can wear the lock cylinders over time, but normal use is safe.
Why does my key fob keep dying?
Key fob batteries typically last two to four years depending on how often you use the fob. If your battery dies much faster, the fob may have a button stuck in the pressed position, draining the battery constantly. Try cleaning the fob buttons with a dry cloth, or contact a Nissan dealer if the problem continues.
Can I use the manual key to lock the car doors?
Yes, you can turn the manual key clockwise in the door lock to lock the door. However, you will need to do this for each door individually. Using the key fob (once the battery is replaced) is faster if you want to lock all doors at once.