topic Re: autofocus working but when going back from manual to auto its not detecting autofocus in EF & RF Lenses

EF-S 18-135mm AF working but when going back from manual to auto its not detecting autofocus

louisse — Thu, 23 Jan 2025 14:54:41 GMT

I use the 18-135mm kit lens this happened after i opened up my lens to fix something. The autofocus stills works but after i put my focus into manual and want to change it back to auto it doesn't detect it but the ring is stiff. I already tried turning it off and on but it still says mf. The only way i could make it go back to af is to remove the lens. I know i did something wrong inside the lens cause there's an extra spring that fell out of the lens please help

Re: autofocus working but when going back from manual to auto its not detecting autofocus

Danny — Sat, 18 Jan 2025 19:44:56 GMT

Thanks for joining the conversation, louisse!

So that the Community can help you better, we need to know exactly which Canon camera model you're using. That, and any other details you'd like to give will help the Community better understand your issue!

If this is a time-sensitive matter, click HERE search our knowledge base or find additional support options HERE.

Thanks and have a great day!

Re: autofocus working but when going back from manual to auto its not detecting autofocus

jrhoffman75 — Sat, 18 Jan 2025 20:21:46 GMT

@louisse wrote:

I use the 18-135mm kit lens this happened after i opened up my lens to fix something. The autofocus stills works but after i put my focus into manual and want to change it back to auto it doesn't detect it but the ring is stiff. I already tried turning it off and on but it still says mf. The only way i could make it go back to af is to remove the lens. I know i did something wrong inside the lens cause there's an extra spring that fell out of the lens please help

You can download a digital parts list from here:

Re: autofocus working but when going back from manual to auto its not detecting autofocus

ebiggs1 — Sun, 19 Jan 2025 17:30:04 GMT

"... i did something wrong inside the lens cause there's an extra spring that fell out of the lens please help "

And exactly why it isn't a good idea for amateurs to do lens repair without training. A digital parts list isn't going to be of much help if the exact location and installation procedure isn't known. Even if you get it back installed you will never be able to trust it as it is certainly guaranteed to fail when you most need it to work.