Canon EOS Error 01 (Err01) – The worst case scenario

Canon’s explanation of the Err01 is “Communications between the camera and the lens is faulty. Clean the lens contact.” Well, life can’t be that simple can it?
I’m sure there are cases where the lens contacts are indeed dirty enough to interfere with communication between the camera and the lens. There are lots of cleaning tips online including the ‘pencil eraser’ method. If that worked for you consider yourself lucky.

Here is the dreaded Err01 message:
Canon EOS XTi - Error 01

No amount of cleaning, resetting and swearing was going to make the error go away on this Rebel XTi. I’ve also verified that it wasn’t the lens, dirty contacts, or the firmware. So I decided to take a deeper look (literally) to see what is really wrong.
Canon EOS XTi - Error 01

Canon EOS XTi - Error 01

Canon EOS XTi - Error 01

It turns out that the internal connector pin that connects the lens contact pin assembly to the circuit board has burnt out! Yes, burnt. The connector was covered with green fungus-like powder and some gooey substance was underneath it. And there were black burn marks on the flexible strip.
Canon EOS XTi - Error 01

Holy crap! how could have this happened? My two guesses are:
A. There were excessive moisture/humidity build up along the contacts while the lens was being removed with the camera powered on. (very unlikely, but a theory nevertheless)

B. The lens motor overloaded the camera. Perhaps, this poor XTi was trying to auto-focus a huge lens for prolonged period of time and/or there were constantly higher than normal resistance from the lens barrel from your hand being in the way, etc… (very likely, especially when using non-ultrasonic lnses).

Canon EOS XTi - Error 01

Canon EOS XTi - Error 01

Canon EOS XTi - Error 01

I carefully cleaned the connector with alcohol. But as you can see, few of the connectors are burnt out and has disappeared from the strip. It’s obviously not going to work as is. But I’ve put the camera back together just to see if it behaves any different. Yep, just as expected – didn’t work. The camera throws same error as before.

Now, I either have to look for a donor Rebel XTi that has the pin connectors intact or the part itself. With some luck and careful soldering, I should be able to bring this poor EOS XTi back to life. Fingers crossed and eyes open on eBay! Although, I should probably contact Canon first to see if they can help me locate the part.
Canon EOS XTi - Error 01


  1. Same prob here.
    I have the Err1 on two bodies but only with the same lens.
    Change the lens contacts is not so easy, so I would prefer the support.

  2. Changing the lens contact is very complicated. The connectors are routed through the shutter box assembly. You’ll end up doing more damage.
    Best way is to buy a used donor that has different problem such as broken LCD or power supply. Then swap the entire back half of the camera.

  3. Buy another Canon XTi, a broken one to use as a donor. A broken XTi can be had for less than $60 these days. Make sure the donor camera has good shutter. Look for ones with LCD or power supply problems. Just make sure you don’t get a donor with the same problem as your camera. Then swap the entire front half of the camera. This is much simpler and safer than separating the shutter box.

    It isn’t that easy to disassemble and reassemble the camera. You do need to de-solder and re-solder an aluminum heat plate of some sort in the process. And there are quite a few delicate connectors and wires that needs to be handled carefully. If you feel adventurous, it is worth a try…

  4. I have a Canon 1100D which has started putting up the error code “01” This is caused by the Camera and Lens not talking to each other. Mine only does it on FULL ZOOM with a TAMRON 75-300.
    I have done some research in to this and found the following from Canon.


    Clean the contacts with a microfiber cloth. They are located on the back of the lens and just inside the lens mount ring on the front of the camera. If that doesn’t help, try swapping the battery in your 1100D.

    This may or may not solve your problem. Sometimes an older third party lens design like the Tamron AF 70-300mm f/4.0-5.6 Di LD Macro Zoom Lens released in 2006 or the Tamron AF 70-300mm f/4.0-5.6 SP Di VC USD XLD released in 2010 will not be fully compatible with a newer body like the Canon 1100D released in 2011. The reason for this is that is that Canon, like other camera manufacturers, does not share its proprietary design information with competitors. So companies like Tamron have to reverse engineer their lenses to be compatible with the Canon bodies that exist at the time they design the lens. Some lens makers have been known to offer “re-chipping” to bring older lenses up to being compatible with newer bodies, but this has generally involved more expensive lenses than the Tamron 70-300 series.

    Hope this helps;


  5. Thank you and fIip! I am not quite up for sodering… so I guess it ‘s time for a new camera. Feeling Annoyed and Hopeful! now to figure out what camera to invest into… obviously this body will not be upto my kind of use. I sure loved it! But it’s from 2012 so it time.

  6. Hi,

    Just one question. If it was the camera body at fault, shouldn’t the same error occur on other lenses as well?


  7. Nooo, don’t scrap the camera. Try using 35mm lens with EF converter ring, use manually.

  8. I had the Error 01 message on my 400D

    I changed the support battery ( CR 2016 3 V) which is placed inside the main battery compartment.

    This did the trick.

    I find it somewhat disappointing that Canon did not establish a dedicated error message for a worn out support battery. The lens contact message led me astray.
    The support battery has been there since the camera was new in 2007 and at first it did not occur to me that it could be the culprit.

    I understand that I was luckier with my fault searching and fixing this time than som of you.

  9. I have Code 01 with an EOS 6D and a Canon 24-105mm series L. Cleaning the lens contact with fiber cloth and erasing rubber did not solve the problem. Autofocus is eractic and sometimes the exposure is wrong. As the problem does not happen with my other lens (40mm and 70-300mm), I guess the problem is inside the lens. Does someone has a tip?

  10. Hi. I’m only getting the err 01 message when using a Tamron 75-300 lense. All my other lenses are ok. I can use the telephoto lens up to about 150mm but then I get the error message. I’ve tried my husbands 75-300 lens with no problem and my Tamron is ok on his camera body. Any suggestions please?

  11. My canon Kiss X50 has shows the error problem,when I shoot in bright area,but when in dark,its jst okay. help

Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/zo0zecq0s37a/public_html/wp/wp-includes/formatting.php on line 4798

Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/zo0zecq0s37a/public_html/wp/wp-includes/formatting.php on line 4798

Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/zo0zecq0s37a/public_html/wp/wp-includes/formatting.php on line 4798

Leave a Reply
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/zo0zecq0s37a/public_html/wp/wp-includes/formatting.php on line 4798

Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/zo0zecq0s37a/public_html/wp/wp-includes/formatting.php on line 4798

Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/zo0zecq0s37a/public_html/wp/wp-includes/formatting.php on line 4798

Your email address will not be published. Required fields are marked *