These instructions apply to the Alfa Romeo GT Mk1 (937) 2004-2011.
For other models, please choose your vehicle here.
When the remote on an Alfa Romeo GT (2004–2011, Type 937 coupé) only locks the car from arm’s length, flashes weakly, or stops responding altogether, the culprit is nearly always the coin cell inside the key. The GT carries the classic Fiat-group folding “flip” key shared with the 147, 156 and 166 — a spring-out metal blade with the remote buttons in the plastic body and, unusually for its era, a rotating battery holder rather than a simple snap-off cover. That holder is what trips people up, so this guide walks the exact opening sequence, the cell you need, and why a spare key is the one thing you can’t sort on the driveway.
How to Tell the Fob Battery Is Dying
- Shrinking range. You have to stand right beside the GT — or almost touch the door with the key — before it locks or unlocks. This is the first and clearest sign.
- Weak or dead LED. The little indicator light on the fob dims or stops flashing on a button press. If a known-good cell brings it back, the battery was the whole story.
- Hit-and-miss buttons. The remote works one press in three, and worse on a cold morning — a near-flat lithium cell sags badly at low temperature.
- Needing several jabs. Repeatedly pressing before anything happens means the transmitter is barely mustering enough power to reach the car.
A coin cell in a GT key typically lasts three to four years. If yours is around that age and showing any of the above, fit a fresh one before you start suspecting the receiver or the immobiliser.
The Battery You Need
The GT flip key takes a single CR2032 — a 3-volt lithium coin cell, 20 mm across — the same battery used across the 147, 156, 166 and GT remotes. It’s the most common fob cell there is, sold in any supermarket, hardware shop or petrol station. Buy a good-quality branded cell: budget cells sag under the brief high current the transmitter draws and can give short range even when box-fresh. As always, the definitive check is the code stamped on the cell you remove — if it doesn’t read CR2032, match whatever is printed there.
How to Change the Battery
- Release the blade. Press the button on the side of the key so the metal blade springs out to its open position. This exposes the seam and the battery access on the body of the fob.
- Turn the opening device. With the blade out, you’ll see a small slotted “lock” on the fob. Using a fine flat-blade (slotted) screwdriver, turn this opener a quarter-turn to unlatch the battery holder — it works like a slotted screw, not a prise-off cover.
- Pull out the battery holder. With the opener released, slide out the little plastic carrier that holds the CR2032. The cell sits inside this carrier rather than under a clip on the board.
- Swap the cell. Note which way the old CR2032 faces in the holder, lift it out, and drop the new one in the same orientation. On this holder the cell normally seats positive (+) face upward — but copy what you removed, because matching the original is what guarantees you’re right.
- Refit and lock. Push the battery holder fully back in, turn the opener back the other quarter-turn to secure it, then fold the blade closed until it clicks. Test every button.
⚠️ Get the orientation right. The GT owner’s handbook specifically tells you to fit the new cell “the right way round.” A coin cell put in backwards makes no contact — and in some holders can short and drain — so always match the way the old one sat before you close the key.
Make Sure It Took
Stand a few metres from the GT and lock, then unlock. Full range should return instantly and the LED should flash crisply on every press. If the remote feels sharp again from across the car park, the job is done. If it’s still hesitant, the holder may not be fully seated — open it back up and reseat the cell and carrier.
If a Fresh Cell Doesn’t Fix It
- Reseat the carrier. The rotating holder must click fully home and the opener must be turned back to lock it — a holder left proud is the commonest reason a “new” battery does nothing.
- Clean the contacts. Wipe the cell faces and the holder terminals with a dry cloth; finger grease or a fleck of corrosion is enough to cause dropouts on a low-power transmitter.
- Confirm the cell is genuinely good. Coin cells can sit dead on a shelf. If the LED still won’t light with a second known-fresh CR2032, the fob’s transmitter or button contacts may have failed — rare next to a simple flat cell, but possible on a car this age.
- Rule out the car. A weak 12 V battery can make the GT slow to respond to the remote. If the car itself is sluggish to wake or the central locking is erratic, look at the vehicle battery rather than the key.
New Key or Spare — Why It’s a Dealer or Locksmith Job
Changing the cell doesn’t touch the fob’s coding, so no reprogramming is needed after a battery swap — the remote and its transponder keep working exactly as before. A new or additional key is a different matter. The GT’s CODE immobiliser has to be told to accept a new transponder, which means a diagnostic tool and, in most cases, the master “CODE card” that came with the car. That puts cutting and coding a spare firmly with an Alfa dealer or a specialist auto-locksmith. The cheapest insurance is to keep the battery in your second key fresh too, so you’re never down to a single working remote.
Frequently Asked Questions
What battery does an Alfa Romeo GT key take?
A single CR2032 3-volt lithium coin cell — the same one used in the related 147, 156 and 166 flip keys. Check the code on the cell you pull out to be certain.
How do I open the GT flip key?
Press the side button so the metal blade springs out, then use a fine flat-blade screwdriver to turn the small opener a quarter-turn and slide out the battery holder. It unlatches like a slotted screw — don’t try to prise the case apart.
Which way up does the battery go?
Fit the new CR2032 the same way the old one sat — usually positive (+) face up in the carrier. The handbook stresses getting the orientation right, so copy the original before you close the key.
Do I need to reprogram the key after a battery change?
No. Replacing the cell leaves the coding untouched, so the remote works straight away. Only a brand-new key needs programming to the car’s immobiliser.
How long should a GT key battery last?
Roughly three to four years. Frequent locking and unlocking, or a fob that lives on a crowded keyring taking knocks, will shorten that.
Can I still get into the car if the fob is completely dead?
Yes. The flip key’s metal blade unlocks the driver’s door manually, and the transponder in the key still lets the car start once the ignition is turned — the dead remote only affects the central-locking buttons, not the immobiliser.
If the remote quit suddenly rather than fading — especially just after the car battery was disconnected — and the central locking is behaving oddly, the fault may be electrical rather than a flat cell; checking for a stored body or immobiliser code at autodtcs.com can point you in the right direction.
Independent guide — not affiliated with Alfa Romeo. Always follow your official service manual and safety precautions. Read our full disclaimer.