Ford Key Fob Battery Replacement: Which Battery (CR2032, CR2450, CR2025) and How to Change It
Most Ford key fobs take one of two batteries: a CR2032 in flip keys, remote head keys, the older separate remotes and the 2011 to 2019 Intelligent Access fobs, or a CR2450 in the larger push-button-start fobs used from about 2015 on (F-150 from 2018, Mustang, Edge, Explorer, Expedition, Escape 2017 on, Bronco). The 2009 to 2012 Intelligent Access keys on the Taurus, Edge, Flex and Lincolns take two CR2025 cells, and so does the 2015 to 2017 F-150 Intelligent Access fob. Read the code on the old battery, open the fob at the slot the emergency key comes out of, swap the cell the same way round, and you are done. No reprogramming is needed.
Ford has sold a lot of different key fobs over the last twenty years, and the battery inside has changed more than once. The job itself is simple, but buying a CR2032 for a fob that wants a CR2450 is a common and annoying mistake. This guide tells you which battery each style of Ford key takes, how to open each one without cracking the case, how to start a push-button Ford when the key is dead, and what to check if a new battery does not bring the fob back.
Which battery your Ford key fob takes
Match your key to the style in the table, then confirm against the code printed on the old battery. The FCC ID on the back of the fob identifies the family if you are unsure.
| Key style | Typical FCC ID | Common on | Battery |
|---|---|---|---|
| Separate 3, 4 or 5-button remote (plain key alongside it) | CWTWB1U331, CWTWB1U345, CWTWB1U793 | F-150 to 2014, Explorer to 2010, Focus to 2011, Escape to 2012, Ranger, Expedition, Mustang to 2014 | CR2032 |
| Flip key or remote head key (buttons on the key itself) | N5F-A08TAA, OUCD6000022, CWTWB1U793 | Focus 2012 on, Fiesta, Escape 2013 on, Fusion keyed trims, F-150 2015 on, Ranger 2019 on, Bronco, Maverick, Transit | CR2032 |
| First Intelligent Access key (long oval) | M3N5WY8406 | Taurus 2009 to 2012, Edge 2011 to 2014 (IA), Flex 2009 to 2012, Lincoln MKS, MKT, MKX 2009 to 2012 | Two CR2025 |
| Second Intelligent Access key (rounded, with emergency key inside) | M3N5WY8609, M3N5WY8610 | Fusion 2013 to 2016, Escape 2013 to 2016, C-Max, Focus 2012 to 2018 (IA), Explorer 2011 to 2015, Edge 2011 to 2014, Flex 2013 to 2019, Taurus 2013 to 2019 | CR2032 |
| Current push-button-start fob (large, flat, no visible key) | M3N-A2C31243300, M3N-A2C93142600, M3N-A2C931426, M3N-A3C054339 | F-150 2018 on, Mustang 2015 on, Edge 2015 on, Explorer 2016 on, Fusion 2017 to 2020, Escape 2017 on, Expedition 2018 on, Bronco, Bronco Sport, Maverick (push button), Lincolns 2015 on | CR2450 |
The CR2450 is noticeably bigger than a CR2032 (24.5 mm across and 5 mm thick against 20 mm and 3.2 mm), so once you have the fob open there is no mistaking which family you have. The code on the flat + face of the old cell is the final word.
F-150 exception: the 2015 to 2017 F-150 Intelligent Access fob takes two CR2025 cells, as listed in the 2015 F-150 owner’s manual. The single CR2450 fob arrived with the 2018 model year. If you have a 2015 to 2017 F-150 with push-button start, open the fob and check before you buy.
The first two digits of a coin cell code are the diameter in millimetres and the last two are the thickness in tenths of a millimetre, which is why none of these three sizes can stand in for another. Our key fob battery size chart lists every common size.
What you need
- One new battery of the exact code on the old one (two, for the 2009 to 2012 Intelligent Access key). Panasonic, Energizer, Duracell and Murata are all fine; Ford dealers sell the same cells in Motorcraft packaging
- A small flat-blade screwdriver or a plastic pry tool
- A clean, well-lit surface so the small rubber button pad and any screw do not go missing
Do not use rechargeable LIR cells. They have the same shape but a higher voltage than the fob is designed for.
Changing the battery in a Ford push-button-start fob (CR2450)
This is the large flat fob on 2015-and-newer Fords with a Start button. The emergency key is hidden inside it.
Press the release button on the back (or slide the catch) and pull the metal key blade out. You will use its tip in the next step.
Look into the slot the emergency key came out of. Put the tip of the key blade or a small flat screwdriver into the notch there and twist. The back cover separates. Work the tool along the seam only if the cover does not come free at the slot; prying at random spots is what leaves marks.
On most of these fobs the + side (with the code printed on it) faces up towards you once the cover is off. Take a photo before you touch it.
Lever it up at the cut-out beside the battery with the key tip or a plastic tool, and lift it out by the edge. Do not drag a metal tool across the circuit board.
Hold the new CR2450 by its edge and press it in the same way round. It should sit flat under the tab without rocking.
Snap the cover back on, slide the emergency key home until it clicks, and press lock and unlock. The small LED on the fob flashes with each press when the battery is good.
Changing the battery in a Ford flip key or remote head key (CR2032)
- Fold the key blade out. Look along the seam of the plastic head for a small slot, usually near the pivot or at the end opposite the blade.
- Put a flat screwdriver or coin in the slot and twist gently. The back cover lifts off, or the two halves split. Some older remote head keys have a tiny Phillips screw on the back; remove it first.
- Note which way the battery faces, then lever it out at the cut-out beside it.
- Press in the new CR2032 the same way round, check the rubber button pad is seated flat in the front half, and snap the case shut until the seam is flush all round.
The transponder chip that lets the car start is sealed in the key head and does not use the battery. A flip key with a dead battery still turns the ignition and starts the engine.
The older Intelligent Access keys
2011 to 2019 rounded IA key (CR2032): slide the catch and remove the emergency key, then put a flat tool in the notch inside the key slot and twist. The back cover comes off and the single CR2032 sits in the cover with the + side up.
2009 to 2012 long oval IA key (two CR2025): pull the small plastic cap off the end opposite the key ring, then slide the back cover off. Two CR2025 cells sit side by side. Replace both at once with the same brand; a fresh cell paired with a tired one gives short range and odd behaviour.
CR2450 3V lithium coin battery (Ford push-button fobs 2015 on)
The large flat Ford fob takes a CR2450. Flip keys, older remotes and the 2011 to 2019 Intelligent Access key take a CR2032 instead. Buy a name brand in a small multi-pack and keep the spares in the glove box.
Other Ford keys: CR2032 · CR2025
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Do you need to reprogram a Ford key after a battery change?
No. The pairing is stored in memory that does not need battery power, so the fob works as soon as the new cell is in. If the dash showed Key battery low or Replace key battery, the message clears after the next start or two. Ford only needs programming for a key that is new to the vehicle, and that is a separate job.
One Ford quirk is worth knowing: on many models you can pair a new remote yourself if you already have two working keys (the owner’s manual calls it programming an Intelligent Access key or the ignition cycling procedure). That is for adding keys, not for a battery change, and it does not help if you are down to one key.
If the car still does not see the key
First, start the vehicle. Every push-button Ford has a backup spot where it can read a key with a flat battery. On most it is a marked slot or pocket in the centre console bin or a cup holder; on some older ones it is a slot in the steering column shroud or the glove box. Put the fob in it, press the brake and push Start. The exact location is in your owner’s manual under Starting with a low battery key or Intelligent Access backup. The emergency key blade opens the driver’s door; on fobs with no visible blade, the lock cylinder is under a small cap on the door handle.
Then check, in this order:
- Battery size. A CR2032 in a CR2450 fob rattles and makes patchy contact. Compare the new code with the old one.
- Battery upside down. No LED flash at all usually means the cell is reversed.
- Flattened contact. The spring contact can be pressed down while prying. Lift it gently with a plastic tool and wipe it with a dry cotton bud. See how to clean key fob battery contacts.
- A flat new battery. Unbranded multi-pack cells, and cells that have sat for years, can be dead in the packet. Try one from a fresh, dated pack.
- Two cells, one replaced. On the 2009 to 2012 IA key, replace both.
- The vehicle’s 12 V battery. If the truck was also slow to crank, the key is not the problem. See can a bad car battery cause key fob problems.
- Damage inside the fob. A fob that has been dropped hard, through the wash or left on a hot dash can have a cracked solder joint. A locksmith can test whether it still transmits before you pay for a new key.
The full checklist is in Ford key fob not working and key fob not working after a battery replacement.
What it costs
Most Ford parts counters will fit a battery while you wait for the price of the cell plus a few dollars. The larger figures only apply when the key itself has to be replaced, which a battery change almost never leads to.
How long the new battery will last
A flip key or separate remote only transmits when you press a button, so a CR2032 in one normally lasts three years or more. A push-button fob listens for the vehicle and answers every time you touch a handle, so a CR2450 in one typically lasts two to three years; its larger capacity is the reason Ford moved to it. Remote start and leaving the fob within a few feet of the vehicle overnight both shorten that. See how long key fob batteries last for a sensible replacement schedule.
Safety: keep coin batteries away from children and pets
A swallowed coin cell can cause serious internal burns within hours. Keep spares and the old cell out of reach, and take old batteries to a drop-off point rather than household waste. If you think a child has swallowed a battery, go to the emergency room straight away and call the National Battery Ingestion Hotline at 1-800-498-8666, or Poison Help at 1-800-222-1222.
Frequently Asked Questions
Flip keys, remote head keys, older separate remotes and the 2011 to 2019 Intelligent Access key take a CR2032. The large push-button fobs from about 2015 on take a CR2450. The 2009 to 2012 Intelligent Access key takes two CR2025 cells. Confirm with the code on the old battery.
On push-button fobs, remove the emergency key and twist a flat tool in the notch inside the key slot. On flip keys, fold the blade out and twist a flat tool in the slot on the seam. The 2009 to 2012 Intelligent Access key opens by pulling off the end cap and sliding the back cover.
No. Ford keys keep their pairing without battery power. The fob works as soon as the new battery is in, and any low key battery message clears after the next start or two.
Put the fob in the backup slot, usually in the centre console bin or a cup holder, then press the brake and push Start. The location is in the owner’s manual under starting with a low battery key. Use the emergency key blade to open the driver’s door.
No. The CR2450 is wider and thicker, so a CR2032 rattles in the holder and loses contact. Use the exact code the fob was designed for.
The vehicle usually needs a start cycle or a day of normal use to update. If it stays on, check that the new cell is the right size, the right way up, and from a fresh pack, and that the contact spring was not flattened.