Start the Car With a Dead Key Fob Battery

Last updated: June 12, 2026

The Chevrolet Spark (M300, 2010–2016) is a turn-key car from end to end: a flip key with a cut blade that you insert and turn in the ignition barrel on the column. It was never offered with push-button start, so a flat fob battery cannot leave you stranded — it only stops the remote locking and unlocking. Here is the full picture and the quick fix.

Start the Car When the Fob Is Dead

The transponder the immobiliser reads is built into the metal blade and needs no battery, so a dead coin cell makes no difference to starting:

1. Press the catch on the fob to flip the cut blade out.
2. Slide it into the ignition barrel on the steering column.
3. Turn to crank as usual — the Spark fires up.

If the engine does not turn over, that is a 12V battery, starter or switch problem rather than the fob. A dead coin cell only ever mutes the remote buttons.

Unlock With the Mechanical Key

The remote will not open the doors when its battery is flat, so use the blade.

1. Flip the cut key out of the fob.
2. Insert it into the driver’s door lock cylinder — only that door has one.
3. Turn to unlock; the alarm may chirp until the ignition is switched on.

About the Immobiliser

The M300 immobiliser surrounds the ignition barrel and verifies the chip in your key on every start. The check is passive and draws nothing from the coin cell, which is why a turn-key Spark always starts on a dead remote. If it cranks but will not run, look at transponder recognition (a faulty or unprogrammed key), not the fob battery.

Replace the Coin Cell

The Spark flip fob uses a single 3V lithium CR2032.

1. Flip the blade out to release the case, then split the halves with a small flat screwdriver.
2. Remove the old CR2032 and note which face points up.
3. Fit the new cell the same way, positive (+) side up, handling it by the rim.
4. Click the case shut and test the buttons by the car.

Frequently Asked Questions

Will my Spark start with a dead key fob? Yes. It is a turn-key car — the cut blade and chip start the engine regardless of the coin cell.

What battery does the Spark fob take? A CR2032 3V lithium coin cell.

Do I need to reprogram after a battery swap? No. Changing the coin cell only restores the remote buttons; the key is not erased.

The lock and unlock buttons died but the car starts — why? That is the standard symptom of a dead coin cell. A new CR2032 brings the buttons back.

Does every door have a keyhole? No — only the driver’s door, so use that barrel to unlock the car.

If a warning lamp stayed lit after you set off, you can look the code up on our sister site autodtcs.com to see if it concerns the key or immobiliser.