How to Replace the Key Fob Battery in a Volvo XC40

1. Hold the key with the Volvo logo facing up, move the button on the key ring section to the right, and slide the front cover slightly upward to remove it.
2. Turn the key over, move the button to the side, and slide the rear cover slightly upward to remove it.
3. Use a screwdriver to turn the battery cover counterclockwise until the markers point to OPEN, then pry the cover up.
4. Carefully pry out the old battery, which has its positive side (+) facing upward.
5. Insert a new CR2032, 3 V battery with the positive side (+) facing upward, sliding it under the plastic catches until it locks.
6. Replace the battery cover and turn it clockwise until it points to CLOSE.
7. Put the rear cover back and press it down until it clicks, then slide the front cover back until a second click.

• Replace the battery when Vehicle key bat. low is shown in the instrument panel.
• Avoid touching the new battery and its contact surfaces with your fingers.
• The Key Tag battery cannot be replaced; order a new key from an authorized Volvo workshop.

Source: 2021 Volvo XC40 owner's manual, PDF pages 230, 231, 232. Steps are summarized in our own words (AI-assisted, checked against the cited pages 2026-10-18). Other model years can differ; your manual has the final word.