These instructions apply to the Mitsubishi Outlander Mk3 (GF) 2012-2021.
For other models, please choose your vehicle here.
If the remote on your Mitsubishi Outlander Mk3 (GF/GG, 2012–2020) only locks the car from an arm’s length away, responds now and then, or has stopped altogether, the coin cell inside it is almost certainly flat. This generation — which spans the petrol and diesel GF models and the GG-chassis Outlander PHEV — shipped with two very different keys depending on trim: a folding “flip” remote on lower and mid-spec cars, and a smart (keyless) FAST key with push-button start on higher trims and every PHEV. They take different batteries and open in different ways, so the first thing to do is work out which one you’re holding. Below is the exact cell and method for each, plus how to tell a dying battery from a real fault.
How to Tell the Fob Battery Is Dying
- Shrinking range. You have to be right beside the Outlander — or press the fob against the door handle — before it will lock or unlock. This is almost always the first sign.
- The LED stops flashing. On the folding remote the little indicator light won’t blink on a button press once voltage drops — a quick way to confirm it’s the fob and not the car.
- A key-battery warning. Keyless (FAST-key) Outlanders show a low key-fob-battery message and chime in the instrument display when the smart key is weak; you may also have to hold the fob touching the start button to get the engine to crank.
- Cold-weather dropouts. Intermittent response on frosty mornings is a near-flat lithium cell struggling in the cold — it often recovers by afternoon, which is a clue the battery is on its way out.
A fob cell in an Outlander typically lasts two to four years. If yours is older than that and doing any of the above, fit a fresh battery before you suspect the receiver or immobiliser.
The Battery You Need
It depends entirely on which key you have:
- Folding “flip” remote (the slim key where the metal blade swings out of the body): a CR1620 3-volt lithium coin cell — a thinner, less common cell than the usual fob battery, so check you’re buying the right one.
- Smart keyless FAST key (the chunkier fob with lock/unlock buttons and no key slot — you start the car with a button): a CR2032 3-volt lithium coin cell, the everyday fob battery sold everywhere.
If you’re ever unsure, the surest guide is the code printed on the cell you take out — buy a like-for-like replacement. In both cases choose a good branded battery; cheap cells sag under the brief high current the transmitter draws and can give poor range even when “new”.
Method 1 — Folding “Flip” Remote (CR1620)
- Fold the metal blade back into the body so the fob is easier to grip.
- Undo the small screw on the back of the fob with a fine cross-head (Phillips) screwdriver and keep it safe — it’s tiny.
- Find the slot along the seam at the base of the fob, insert a small flat-blade screwdriver and twist gently to split the two halves.
- Note which way the old cell faces, then ease it out. Fit the new CR1620 positive (+) side up, sliding it under the plastic retaining tabs first, then pressing the far edge down until it clicks under the clip.
- Close the halves, drive the screw back in snugly — don’t overtighten the plastic case — and test every button.
Method 2 — Smart Keyless FAST Key (CR2032)
- Release the emergency blade: slide the small catch on the fob and pull the mechanical key blade straight out of the body.
- Slip the blade tip, or a flat plastic pry tool, into the gap the blade leaves and gently lever the case apart. Working from that slot avoids marking the fob.
- Lift out the old CR2032, taking care not to bend the metal contact arm. Note the orientation before it comes free and fit the new cell exactly the same way round.
- Press the two halves back together until they click, then slide the emergency blade home until it latches.
⚠️ Get the polarity right. A coin cell fitted the wrong way up won’t power the transmitter, and on some fobs it can quietly discharge against the contacts — so always copy the exact orientation of the cell you removed rather than guessing. If in doubt, the “+” marking on the cell should face the same way as the one that came out.
Confirm It Worked
Stand back a few metres and lock, then unlock, the Outlander. Full range should return straight away, and on the folding remote the LED will flash cleanly again. On a keyless car the low-key warning clears once the system next reads a healthy fob — sometimes instantly, sometimes after a short drive. If the engine needed the fob held to the start button before, it should now crank normally from your pocket.
If a Fresh Cell Doesn’t Fix It
- Re-check polarity and seating. A cell in upside-down or not fully clipped under its tab is the single most common reason a “new” battery seems dead.
- Confirm the cell code. The two Outlander keys take different batteries — CR1620 for the flip remote, CR2032 for the smart key — so a fob that still won’t respond may simply have the wrong (or a very cheap) cell in it.
- Wipe the contacts. Finger grease or light corrosion on the terminals is enough to cause dropouts; clean them with a dry cloth and reseat the cell.
- Rule out the car. A weak 12 V vehicle battery can mimic key faults — if the Outlander is slow to wake or the dash flickers when you unlock, have the main battery load-tested.
New Key or Spare — Why It’s a Dealer Job
Changing the cell keeps the fob’s existing coding, so nothing needs reprogramming and the remote works the moment the case is back together. Adding a new key is a different matter: Mitsubishi’s immobiliser has to be accessed with dealer-level diagnostic equipment, and blank smart keys must be ordered and coded against the car’s VIN — the FAST-key system on the Outlander won’t accept a self-taught spare. That makes cutting and coding a replacement a job for a Mitsubishi dealer or an auto-locksmith. The cheap insurance is to keep the battery in your spare key fresh too, so you’re never down to one working fob.
Frequently Asked Questions
What battery does a Mitsubishi Outlander Mk3 key fob take?
It depends on the key. The folding “flip” remote uses a CR1620 3-volt lithium cell; the smart keyless FAST key (push-button start, fitted to higher trims and all PHEV models) uses a CR2032. Check the code on the old cell if you’re unsure which you have.
Is the Outlander PHEV key the same as the petrol one?
The PHEV is always supplied with the smart keyless FAST key, so it takes a CR2032. A petrol or diesel GF Outlander on a lower trim may instead have the folding remote, which takes the smaller CR1620.
Which way up does the battery go?
On the folding remote the CR1620 usually sits positive (+) side up. On the smart key, note how the old CR2032 is oriented before you lift it out and fit the new one the same way — copying the cell you removed is the reliable rule for either key.
Do I have to reprogram the key after changing the battery?
No. A battery swap doesn’t affect the fob’s coding, so it works immediately. Only a brand-new or replacement key needs programming to the car.
How long should an Outlander key battery last?
Around two to four years. Heavy remote use, or leaving a keyless fob sitting close to the car so it keeps waking, will shorten that.
Can I still drive if the fob battery is completely dead?
Yes. On the folding key, use the metal blade to unlock the driver’s door. On the keyless FAST key, pull out the hidden emergency blade to unlock the door, then hold the fob against the engine start button while pressing it — the car reads the transponder directly and will start even with a flat cell.
If your remote quit suddenly — especially just after the car’s 12 V battery was disconnected — rather than fading over weeks, the cause is more likely the immobiliser pairing than the coin cell, and the car may have logged a fault. You can look up what a stored code means on autodtcs.com.
Independent guide — not affiliated with Mitsubishi. Always follow your official service manual and safety precautions. Read our full disclaimer.