Start the Car With a Dead Key Fob Battery

Last updated: June 12, 2026

The Chevrolet Aveo (T300, 2011–2015) uses a conventional ignition across the range: a two-button flip key with a cut blade that you turn in a barrel on the steering column. There is no push-button start on this model, so a flat fob battery never actually stops the car — it only kills the remote lock and unlock. Here is exactly what happens and how to put it right.

Start the Car When the Fob Is Dead

The chip the immobiliser checks lives in the key blade and draws no power from the coin cell, so a dead remote has no effect on starting:

1. Press the catch on the fob and flip the cut blade out.
2. Insert it into the ignition barrel on the column.
3. Turn it to crank exactly as normal — the Aveo starts.

If the engine will not turn over at all, that is a starting fault (12V battery, starter or ignition switch), not the coin cell. A flat fob battery only ever silences the remote buttons.

Unlock With the Mechanical Key

With the remote dead the doors will not open by radio, 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 a barrel.
3. Turn to unlock. The alarm may sound until you switch the ignition on.

About the Immobiliser

The T300 immobiliser box sits around the ignition barrel and reads the transponder inside your key each time you start. That handshake is passive, so it works with a completely flat coin cell. If the car cranks but will not run, suspect transponder recognition (a worn or unprogrammed key), not the remote battery.

Replace the Coin Cell

The Aveo flip fob takes a single 3V lithium CR2032.

1. Flip the blade out to free the case, then ease the two halves apart with a small flat screwdriver.
2. Lift out the old CR2032 and note its orientation.
3. Fit the new cell positive (+) side up the same way, holding it by the edge.
4. Snap the case shut and test lock/unlock standing by the car.

Frequently Asked Questions

Can I start my Aveo with a dead key fob? Yes — it is a turn-key car. The cut blade and its chip start the engine no matter the state of the coin cell.

Which battery does the Aveo fob use? A CR2032 3V lithium coin cell.

Do I have to reprogram the remote after changing the battery? No. The coin cell only feeds the remote buttons; swapping it does not erase the key.

My buttons stopped working but the car still starts — normal? Yes. That is the textbook sign of a dead coin cell. Fit a fresh CR2032 to bring the buttons back.

Only the driver’s door has a keyhole — is that right? Yes, the other doors are slave-locked, so use the driver’s barrel to get in.

If a warning light came on after you drove away, decode the exact fault on our sister site autodtcs.com to check whether it relates to the key or immobiliser.