These instructions apply to the Toyota Aygo Mk1 (B10) 2005-2014.
For other models, please choose your vehicle here.
A blown headlight bulb is a quick DIY fix on the Toyota Aygo, and it is an MOT failure if you leave it. The Aygo uses a single H4 halogen bulb per headlight for both dipped and main beam, reached from behind the light in the engine bay.
What bulb does a Toyota Aygo headlight use?
- Headlight (dip + main beam): H4 halogen, 60/55 W
- Front fog light (if fitted): H11 halogen
- Front turn signal, position and side lights use small wedge/capless bulbs
Buy the H4 bulb before you start — most motor factors and parts shops stock it.
How to replace a headlight bulb
- Turn the lights off and open the hood. Let the bulb cool for a minute if the lights were just on — they get very hot.
- At the back of the headlight unit, unplug the electrical connector from the bulb.
- Pull off the round rubber cover behind the bulb.
- Release the wire bulb-retaining spring and swing it clear, then lift the old H4 bulb out.
- Fit the new bulb so the tabs on its base line up with the cutouts in the mounting hole, then clip the retaining spring back over it. Do not touch the glass with bare fingers — hold the metal base, as skin oils shorten the bulb’s life.
- Refit the rubber cover squarely so it seals all the way round, then plug the connector back in and test both beams.
Replacing the front fog bulb
The H11 fog bulb is reached from under the front bumper by partly removing the fender liner. Unplug the connector, turn the bulb base counterclockwise to release it, fit the new bulb and lock it back in. Then switch the fog lights on once to check no light leaks around the mounting.
If the new bulb doesn’t work
If a fresh bulb still won’t light, check the connector is fully seated and look at the relevant fuse — see the Aygo fuse box guide. If both headlights fail together it is more likely a fuse, relay or switch than two bulbs at once.
Frequently asked questions
What headlight bulb does a Toyota Aygo take?
An H4 halogen bulb, 60/55 W, one per headlight covering both dipped and main beam. The front fog lights, where fitted, use H11 bulbs.
Why shouldn’t I touch the glass of the new bulb?
Oil from your fingers creates a hot spot on the glass that can make the bulb fail early or crack. Hold it by the metal or plastic base, and wipe it with alcohol if you do touch the glass.
Do I need to remove the headlight unit?
No. The H4 bulb is changed from behind the headlight in the engine bay — remove the rubber cover, release the spring clip and swap the bulb.
One side is much dimmer than the other — is that the bulb?
An aging halogen bulb dims and yellows before it fails, so replacing a dim one is normal. If a new bulb is still dim, check the earth connection and the headlight’s reflector and lens for clouding.
If a bulb-out or lighting warning shows on the dash, you can look up what the specific symbol or fault code means on autodtcs.com.
Independent guide — not affiliated with Toyota. Always follow your official service manual and safety precautions. Read our full disclaimer.