Replace the Key Fob Battery

Last updated: June 6, 2026

A Peugeot 208 Mk1 (2012–2019) remote that only works close to the car, needs several presses, or has stopped responding is nearly always down to a flat coin cell. The swap is quick, and unlike many cars the 208 has a genuine owner re-synchronisation you can run yourself if the remote drifts out of step. Here is the full job, plus the limit on programming a new key.

Battery First

The 208 fob uses a CR2032 coin cell (some early flip-key remotes use a CR1620 — check the old one). A weak cell causes almost every unreliable-remote complaint, so fit a fresh one before suspecting anything else. The integrated blade always opens the driver’s door.

Replacing the Fob Battery

1. Remove the key cover — ease the case open at the seam with a small screwdriver.
2. Lift out the old cell (CR2032, or CR1620 on some flip keys).
3. Fit the new cell the same way round, handling it by the edge.
4. Refit the cover and check each remote will lock and unlock the car.

Re-synchronising the Remote (Owner Procedure)

If the remote stops working after the battery has been flat — or after a swap — the 208 re-pairs without any tool:

1. Turn the ignition off, then on.
2. Press the lock button on the remote once.
3. Turn the ignition off and remove the key.
4. The remote is synchronised — test lock and unlock.

Tip: make a careful note of the key number printed on the label that came with the key, and don’t repeatedly press the remote out of range — that can desynchronise it in the first place.

Lost Key or Adding a Spare

The resync above only works for a remote the car already knows. Coding a brand-new key involves the immobiliser and needs Peugeot dealer or auto-locksmith equipment.

If a New Cell and Resync Don’t Help

• Check polarity and the contacts — the usual reasons a swap fails.
• Confirm the cell size — fitting a CR1620 where a CR2032 belongs (or vice-versa) gives poor contact.
• Still dead? A BSI or receiver fault may be storing a code — look it up on autodtcs.com.

Frequently Asked Questions

What battery does the 208 Mk1 key fob use?

Usually a CR2032; some early flip-key remotes use a CR1620 — always check the old cell.

Do I need a dealer to resync the remote?

No — the ignition-on, press-lock, ignition-off sequence above re-pairs an existing remote with no tool.

Can I program a new 208 key myself?

No — a new key must be coded to the immobiliser by a dealer or locksmith.

Why did my remote lose sync?

Often a flat cell, or repeatedly pressing the buttons out of range of the car — the resync restores it.

If the remote went quiet right after a battery disconnection, our 208 Mk1 battery disconnect/reconnect guide covers the resync in context.