Start the Car With a Dead Key Fob Battery

Last updated: June 12, 2026

The Genesis GV70 (JK1, 2020–2024), in both the petrol/diesel models and the Electrified GV70 EV, uses a premium Smart Key with proximity entry and a START/STOP button. When the fob’s coin cell dies, remote locking and hands-free detection stop — but the GV70 still starts once you press the fob directly against the button, and a metal blade lets you in.

Start the GV70 With a Dead Fob

If the cluster shows “Key not detected”, the fob’s radio is flat but the car can still read the key’s passive transponder at close range.

1. Get inside with the emergency key blade first (see below) and sit in the driver’s seat.
2. Press the brake pedal firmly and hold it. On the Electrified GV70 the same brake-and-press routine brings the car to READY rather than cranking an engine.
3. Hold the Smart Key flat against the START/STOP button so the transponder lines up with the reader coil behind it. Genesis places the backup reader at the button itself — touch the fob to it directly.
4. Press the button through the fob. The coil energises the chip, the immobiliser verifies the key, and the GV70 starts or goes to READY.

Unlock the Door With the Emergency Key Blade

On 2021-onward Genesis SUVs including the GV70 there is no separate keyhole cap to lever off — the lock is hidden behind the door handle and revealed when you pull the handle out.

1. Press the release on the Smart Key and slide out the metal emergency blade.
2. Pull the driver’s door handle to its open position; the hidden keyhole appears behind it.
3. Insert the blade into the exposed keyhole and turn to unlock. The alarm may sound; starting the car clears it.

Why a Flat Battery Doesn’t Strand You

The chip that authorises the drivetrain is a passive RFID transponder with no battery of its own. The car energises it by induction through the coil at the START/STOP button. The coin cell only powered the remote-lock radio and the proximity broadcast for hands-free use. A dead cell costs you remote locking and walk-up detection — never the ability to start.

Replace the Coin Cell

1. Slide the emergency blade out to open the seam in the Smart Key case.
2. Twist the halves apart at the seam with a coin or thin plastic tool.
3. The GV70 Smart Key uses one CR2032 3V lithium coin cell. Note the orientation — the plus (+) side usually faces the back cover.
4. Fit the fresh cell the same way up, handling it by the edges, and click the case shut.

Remote locking and keyless entry return at once. Expect two to three years from a quality cell.

Frequently Asked Questions

Where exactly do I hold the fob to start the GV70? Flat against the START/STOP button with the brake held, then press the button with the fob still touching it. The backup reader sits at the button.

How do I reach the keyhole — there’s no cap? Pull the driver’s door handle to its open position and the keyhole appears behind it; insert the emergency blade there.

Does the Electrified GV70 start the same way? Yes. Hold the fob to the button with the brake pressed; the EV shows READY instead of starting an engine.

Why did the alarm sound when I used the blade? Manual entry reads as a possible break-in until the transponder is verified. Starting the car cancels it.

Which battery does the GV70 Smart Key take? A single CR2032 3V lithium coin cell, available almost anywhere.

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