Start the Car With a Dead Key Fob Battery

The Jaguar F-Type (X152, 2013–Present) is a keyless sports car with push-button START/STOP: keep the smart key on you and the doors sense it, then a press of the button fires the engine. When the coin cell in the fob goes flat the key stops transmitting, so the F-Type can no longer detect it across the cabin — touch-unlock fails and the start button looks dead. The car is fine. Jaguar builds a battery-free backup into the F-Type key, and you can be moving again in under a minute.

Start the F-Type With a Dead Fob Battery

The transponder chip in the key draws no power from the coin cell. Held against the reader, the car energises and reads it directly — the same principle as a basic immobiliser key.

1. Sit in the driver’s seat with the key in hand and your foot firmly on the brake.
2. Locate the key symbol on the steering column shroud — on the F-Type it is on the left or lower side of the column cover.
3. Hold the fob flat against that symbol with the buttons facing outward, away from the column.
4. Keeping the key in place, press the START/STOP button. The engine should start.
5. Once running, you can move the key to a pocket or cubby for the rest of the drive.

If it does not catch first time, shift the fob a few millimetres and try again — the antenna behind the shroud has a small sweet spot. Hold the key steady against the marked area while you press the button rather than tapping it.

Unlock the Door With the Hidden Emergency Key

If the fob is too flat to unlock the F-Type remotely, the key hides a metal blade for the door lock.

1. Press the release catch or slider on the side of the smart key and pull the emergency blade out.
2. Go to the door lock barrel, hidden under a cap on the door handle (on some F-Type cars the lock is on the passenger-side handle — check both if the driver’s handle has no slot).
3. Insert the blade tip and lever the cap off to expose the lock cylinder.
4. On the F-Type you may need to pull the door handle fully out and hold it there while turning the blade to release the door, then refit the cap.

Opening the door this way will usually set off the alarm. That is normal — with a dead fob the F-Type has no radio confirmation of a valid key, so it treats the entry as a break-in. It stops the instant you complete the reader start above.

Why the Immobiliser Still Lets You In

The F-Type immobiliser is satisfied by the passive transponder, not the radio signal. Pressing the key on the reader proves a genuine key is present, so the engine control unit releases ignition and fuelling. A flat coin cell never strands you in the F-Type — this fallback was designed in for exactly this scenario.

Replace the Fob Battery

The F-Type smart key takes a single CR2032 3V lithium coin cell. Slide out the emergency blade, split the fob halves at the seam, lift out the spent cell, and fit the new one with the “+” face matching the holder. Press the case shut and full radio range returns. A spare CR2032 in the car means you never have to repeat the dead-fob routine.

Frequently Asked Questions

Where is the start reader on the F-Type? On the left or lower side of the steering column cover, marked with a key symbol. Hold the fob flat against it, buttons facing out.

Why did the alarm sound when I used the blade? The dead fob cannot send the valid-key signal, so the F-Type reads the door opening as forced entry. It silences as soon as the engine starts from the reader.

Which door has the emergency keyhole? Under a cap on the door handle; on some F-Type cars the lock cylinder is on the passenger-side handle, so check both if the driver’s side has no slot.

What battery does the F-Type key use? A single CR2032 lithium coin cell, sold in any supermarket or hardware shop.

Can I drive after a dead-fob start? Yes. The F-Type runs for the whole trip, but fit a fresh battery before switching off so the key works normally next time.

If a warning lamp stayed lit after the alarm cleared, you can look the code up at autodtcs.com before deciding whether it needs attention.