These instructions apply to the Toyota Yaris Mk3 (XP130/P13) 2011-2020.
For other models, please choose your vehicle here.
Over the life of a Toyota Yaris the remote controls will eventually need attention. The small coin-cell battery inside each fob slowly runs down, so the buttons start working only at close range or intermittently, and if a fob is ever replaced or a spare added it has to be paired to the car before it will lock, unlock or authorise a start.
This guide walks through both jobs: reprogramming a remote and renewing the coin-cell battery, covering the two fob styles fitted to the Yaris – one with keyless entry and one without. None of this is a fault; it is routine upkeep that keeps your remote responding first time.
How the Remote Works on the Yaris
The Yaris fob combines a radio transmitter for the lock and unlock buttons with a transponder that the car reads to confirm an authorised key is present. The coin cell only powers the radio side – the buttons and, on keyless cars, the passive detection.
Because the fob and the car swap a rolling security code, a new or blank remote cannot simply be slotted in; it has to be introduced to the immobiliser so both sides share the same code. That pairing step is what needs the workshop equipment described below, whereas a flat battery is a straightforward do-it-yourself change.
Before You Begin
- Identify which fob you have – keyless-entry (proximity) or a standard remote with a fixed blade – as the battery-change method differs.
- Buy the correct coin-cell type for your fob before opening it – a CR2016 for a standard remote, a CR2032 for a keyless (smart) key – and have it ready so the compartment is exposed for the shortest time.
- Work on a clean, well-lit surface and keep the tiny screws and cover clips where they cannot roll away.
- Note the orientation of the old battery as you remove it so the new one goes back the same way.
- For programming, the car must be accessible with the diagnostic equipment, so plan that step with a properly equipped workshop rather than attempting it blind.
Programming the Remote Control
This procedure requires the use of diagnostic equipment – it is not an owner shortcut and cannot be completed with button sequences alone on this model.
- Connect the diagnostic tool to the vehicle.
- Follow the step-by-step instructions shown on the device screen.
Replacing the Battery – Remote with Keyless Entry
- Press and hold the release button to remove the mechanical key.
- Insert a small screwdriver into the slot and carefully remove the protective cover. Do not use excessive force.
- Take out the old coin-cell battery, avoiding contact with the metal terminals.
- Insert a new CR2032 coin-cell battery with the positive side facing up.
- Refit the cover and reinsert the key.
- Test the remote to ensure it works correctly.
Replacing the Battery – Remote without Keyless Entry
- Use a small screwdriver to remove the protective cover, taking care not to apply too much force.
- Insert a coin into the slot to open the battery compartment.
- Remove the old coin-cell battery without touching the pins inside.
- Place a new CR2016 coin-cell battery with the positive side facing up.
- Reassemble the cover.
- Test the remote control.
If It Doesn’t Work
- Buttons still dead after a battery change: confirm the new cell is seated with the correct side up and that both contacts are touching the terminals cleanly.
- Weak or short range: the cell may be a low-quality or partly discharged unit – try a fresh, correct-type battery.
- Intermittent operation after reassembly: reopen and check the cover has clipped fully home so pressure is holding the cell in place.
- A newly fitted or spare fob does nothing at all: it has not been paired – the programming step with diagnostic equipment is still required.
- Keyless (passive) functions failing while the buttons work: this points to fob electronics rather than the battery, so have the remote checked.
What to Expect Afterwards
With a good battery correctly fitted, the lock and unlock buttons should respond immediately at normal range, and on keyless cars the door handle and start button should recognise the fob again. After successful programming the remote will lock, unlock and authorise a start exactly like the original. Always use the correct battery type recommended for your Toyota Yaris remote, and keep your spare fob working so you are never left with a single key.
Frequently Asked Questions
Can I program a Yaris remote at home without any tools?
No. On this model the fob has to be introduced to the car’s immobiliser using diagnostic equipment. A flat-battery change is a simple home job, but pairing a new or spare remote needs the tool connected to the vehicle so the security codes can be matched.
Which coin-cell battery does my Yaris fob take?
On the XP130 Yaris it depends on the fob style: the standard remote without keyless entry takes a CR2016 lithium coin cell, while the smart (keyless-entry) electronic key takes a CR2032. Check the marking on the cell you remove to confirm, and buy the exact matching type, as a different size can sit loosely and cause weak range or intermittent operation.
Why did my remote stop working after I changed the battery?
Usually the new cell is upside down, not seated firmly, or the cover has not clipped fully closed so the contacts are not gripping. Reopen the fob, confirm the positive side faces up, clean the terminals and reassemble until it clicks home.
My keyless entry works but the buttons don’t – is that the battery?
Possibly, since the coin cell powers the button transmitter. Fit a fresh, correct battery first. If the buttons stay dead while passive keyless functions still work, the fault is more likely in the fob’s button electronics and it should be inspected.
Do I need to keep the old fob when adding a spare?
Yes, keep every working key. Programming is easier and more reliable when all existing remotes are present, and having a known-good spare means you are covered if one fails or is lost.
Will a dead fob battery stop the car from starting?
On a keyless car a very weak battery can prevent the passive start being detected, though there is usually a backup method to hold the fob against a marked spot. On a standard fob the transponder still lets the engine start even if the button battery is flat.
For related warning-light and fault-code questions on your Yaris – for example a security or immobiliser message that appears after key work – the DTC reference guides at autodtcs.com explain what the codes mean and where to look next.
Independent guide — not affiliated with Toyota. Always follow your official service manual and safety precautions. Read our full disclaimer.