These instructions apply to the Land Rover Range Rover Mk4 (L405) 2013-2022.
For other models, please choose your vehicle here.
The Land Rover Range Rover (L405, 2013–2022) is a keyless-start flagship: the smart key talks to the car over a short-range radio link, and a flat coin cell inside the fob breaks that link. When the dashboard shows “Smart Key Not Found” or the START/STOP button stays dead, the fob battery is almost always the cause — and the L405 has a built-in backup so you can still get in and drive away.
Start the Engine With a Dead Fob Battery
The car reads the key’s transponder chip by induction once the fob is held physically close to the ignition — no battery needed for that handshake.
- Sit in the driver’s seat and close the door.
- Hold the smart key flat against the underside of the steering column, button face toward the column. If the message centre instead pictures the fob against the START/STOP button, follow the display and hold it there.
- Press and hold the brake pedal.
- With the fob still in place, press the START/STOP button. The engine starts and you can drive away normally.
If it doesn’t start first time, reposition the fob slightly and try again.
Unlock the Door With the Hidden Emergency Key
If central locking won’t respond, use the steel emergency blade inside the smart key.
- Press and hold the release catch on the side of the fob, then slide out the emergency key blade.
- The driver’s door lock cylinder is hidden under a small cap at the rear of the handle.
- Insert the blade into the slot at the base of the cap and lever it off to expose the keyhole.
- Insert the blade and turn to unlock the door.
- Refit the cap afterwards so the handle looks factory-correct.
Expect the Alarm
Opening the door with the blade can trigger the alarm, because the car hasn’t seen a valid radio handshake. Get in and complete the dead-fob start — starting the engine with the recognised transponder disarms the immobiliser and silences the siren.
Replace the CR2032 Coin Cell
The L405 smart key runs on one CR2032 3-volt lithium coin cell. Slide out the emergency blade, then use the blade slot to split the fob halves. Fit a fresh CR2032 with the + side oriented the same way as the original and click the case shut. Full keyless and remote-locking range returns immediately.
Frequently Asked Questions
Where do I hold the key to start the Range Rover L405? Against the underside of the steering column, button-side toward the column — unless the dash pictures the START/STOP button, in which case hold it there.
My door keyhole cap fell off — is that normal? The cap is a press-fit part and can work loose over the years; if yours is missing, the cylinder is simply already exposed at the rear of the handle. Replacement caps are inexpensive.
The alarm sounded when I used the blade — is that a fault? No. The blade opens the lock but doesn’t tell the alarm a valid key is present. Starting the engine clears it.
Will the low fob battery harm anything? No — you only lose remote and keyless range. Replace the CR2032 and everything returns to normal.
How long does the fob battery last? Two to three years typically. Replace it as soon as keyless range starts dropping.
If a warning lamp stayed on after the flat-battery episode, decode the stored fault code at autodtcs.com.
Independent guide — not affiliated with Land Rover. Always follow your official service manual and safety precautions. Read our full disclaimer.