Start the Car With a Dead Key Fob Battery

Last updated: June 12, 2026

The Suzuki Ignis (Mk3/MF, 2016–Present) is sold with Suzuki’s keyless smart entry and a START/STOP button on SZ5 and Keyless trims, and with a remote flip key in an ignition barrel on lower SZ3 trims. When the smart fob’s coin cell goes flat the remote-lock buttons stop responding, but the immobiliser still reads the key — on push-button cars by holding the fob against the start switch, on flip-key cars via the blade in the barrel.

Start a keyless Ignis Mk3 with a dead fob

If your Ignis has the START/STOP button:

1. Unlock and enter the car with the emergency blade first (next section), sit in the driver’s seat and close the door.
2. Press and hold the brake pedal with the selector in N (manual) or P (auto).
3. Hold the flat back of the smart fob directly against the START/STOP button — the button has a short-range coil that reads the fob at close contact.
4. With the fob still touching the button, press the START/STOP button. The engine starts.
5. If nothing happens, reposition the fob flush against the button and repeat — a weak cell needs the fob touching the switch.

Turn-key Ignis Mk3 — the blade starts it

On an SZ3 with an ignition barrel, a flat fob disables only the remote buttons. Pull the blade from the flip key, unlock the driver’s door, slot the key into the barrel and start as normal. The transponder in the key head is energised by the barrel, so a dead coin cell does not stop it starting.

Unlock the Ignis Mk3 with the emergency key blade

1. Slide the release catch on the back of the smart fob and pull the metal blade free of the body.
2. Insert the blade into the lock barrel in the driver’s door handle and turn to unlock.
3. The alarm may chirp until the engine is started; running the car clears it.

Immobiliser note

The Ignis immobiliser reads a passive RFID transponder, not the fob battery. On a keyless car the back-up reader sits in the START/STOP button; on a turn-key car the ring around the barrel reads the chip. The car supplies the power, so the engine authorises even with a fully dead fob. Note that the Ignis SHVS is a 12V mild hybrid, not a 48V system — its small 12V battery still runs the keyless and immobiliser circuits, so if that battery is flat the car will not wake regardless of the fob. A key warning still lit after starting points to a real fault.

Replace the fob battery

The Ignis Mk3 smart fob uses one CR2032 3V lithium coin cell. Slide out the emergency blade, split the case halves at the seam left behind — a coin or thin flat screwdriver in the slot pops them apart — then swap the cell + side up and click it shut. Remote functions return immediately.

Frequently Asked Questions

Does my Ignis Mk3 have keyless start?

SZ5 and Keyless trims do, with a START/STOP button. SZ3 cars use a flip key in an ignition barrel and only need the blade.

Where do I hold the fob to start a keyless Ignis?

Directly against the START/STOP button. There is no key slot or column reader on this model — the back-up coil is in the button.

The Ignis is a hybrid — is the 12V battery different?

The Ignis SHVS is a 12V mild hybrid (not 48V). The keyless system runs off the standard 12V battery; if that is flat, charge or jump it before expecting the dead-fob start to work.

Which battery does the Ignis Mk3 fob take?

One CR2032 coin cell, available in any supermarket or hardware shop.

Why did the alarm sound when I used the blade?

Mechanical entry registers as a possible break-in until the transponder is read. Starting the engine cancels the alarm.

If a dashboard warning light stayed on after the no-start, look it up on autodtcs.com to confirm it was just the fob and not an immobiliser code.