Err 01 Communication between Camera & Lens is Faulty

Cleaning the contacts did nothing for me. what ended up fixing it was turning the camera to AV mode and setting to the highest f value. (f22) and then taking a picture. after that i was able to change it to what ever and resume as normal. hoping i dont see that error again.

Most of the old Sigmas have problems with the Digital Canons. Sigma didn't buy the EF patent so they tryed to reverse enginer it. The "BUG" is regarding aperture. you can only use then in AV mode (the lowest F in you lens). I use a Sigma 70-210 and a 70-300 APO this way.
Only the new Sigmas (it has DL on the name) are fixed not to return that error.
PS - If the lens is in any other F that it's not the lowest one it will always give the error (even in AV mode). You need to go into a 35mm Canon with EF and set it to the lower F. Then you can use in Digital EOS Canon Cameras.

I had the same prob with the Sigma lens [70-300mm af] and was pulling my hair out. I have a new Canon EOS 40d that would constantly give me the dreaded "err 01". No matter how much I cleaned the contacts or adjusted the aperture, nothing would work. I tried turning the auto focus off and on, pulled the focal length in and out, nothing. I ended up buying an after-market battery grip on ebay [$120.00 and came with two batteries] and had another go at attaching the lens. Straight away, bang, it worked. It seems, at least in my case, the single battery in the camera just doesnt have enough oomph to run the lense. It even works now in maximum burst mode, which is what you really want for shooting fast moving distant events. I'm stoked. [that's happy in aussie slang.] Hope this helps you out.
Regards
Jason

I have this same problem, with a canon T1i. i did this n it works out:
switch off then switch on ur camera. DONOT FOCUS OR do anything. put camera to AV(aperture priority) and set to lowest F no. 4 in this case, point , focus manually --shoot! works all the time! PS. this is a software bug error not a physical error, so DONT clean the, contacts, dont press down n stuff!
njoi!

Try to clean the electrical contacts between the camera and the lens with an eraser. Be careful not to let any debris fall into the camera body. If this lens has an aperture ring, set it to the minimum aperture (maximum number available)

Okay so i have a similar problem. On a 40D with the 17-85mm lens.
I haven't found anything useful re permanent fixes. It seems this issue is widespread and apparently due to bad build quality..
TEMP FIX: I leave the aperture at 4 and its fine but when i put it higher i get err 01 then i find if i zoom a little anything past 24-35 range and i can jack the aperture up as much as i desire. Just a little hint so you dont ditch your lens altogether. peace

There is aparrently a similar problem not just with your Tamron lens, but also with Sigma lenses. I have just been given the Sigma 70-300 APO for Christmas for my 450D. I am somewhat disappointed. In full auto mode (idiot mode) only it seems to work fine, but in P mode and TV, in which I mostly work, it returns "comunication between camera and lens is faulty,clean the lens contacts". The contacts are not dirty - just to be safe I cleaned them with a trusted contact cleaner (I'm an electronics engineer and know about contacts). With my daughter's 350D it will not work at all.
These two manufacturers are of course manufacturing lenses in competition with Canon !!! Canon lenses are good, the top of the range are argueably if not possibly the best available today -but at a price only the professional or banker can afford (sadly) I've borrowed a couple of their top lenses in the past - wow!
I am going to try a firmware update, if this does not work then I will contact both Canon and Sigma. Perhaps they will have a solution. I doubt it, the problem has been known for a long time it seems. Look into other Forums for help as well. The problems are varied and sometimes erratic. Hope this helps ... OK, not really !

I have the same problem with my newly purchased 50D and my old Sigma 75-300 that I use with my 650 EOS 35mm. The Sigma is the only lens that I have a problem with and it works fine on my 35mm.

I have found that putting a moderately slight downward pressure on the lens works. The contacts are located in the bottom portion of the lens/camera interface and this seems to increase the contact between the two. I hold the lens at about the halfway point when I do this, with my hand placed on the side to top of the lens, pulling down. So far, it does not appear to interfere with the pop-up flash coverage, although I usually shoot with a Speedlite.

I buying a battery grip because I want the extra battery life, not because of this. But if it helps with this problem, that's o.k., also. I know that putting the slightly moderate pressure down on the lens will not hurt the camera (or the mount), but still, I shouldn't have to do that to operate it with this lens.

I've just purchased a new Canon EOS 60D, and experienced this problem when using my 15 year old Sigma 170-500 EPO lens. The work around, as MarsWalker so helpfully points out, is to use the widest aperture setting on the lens. I found that any other aperture setting other than the widest resulted in this error.

Had the same problem with a new tamron 17-50 on canon 550. i took the battery off. turned on the camera (witout the baterry) turned it off and then on again with the battery. IT WORKS!!!!

Well even me i had a problem like that since long err 01. I stop using my Sigma 18-200mm bcoz of that may be almost 6 yrs it was just lying like that. So one day i thought somebody would want it so i thought of selling it I pulled out the lens clean it and was going to sale it at a cheap rate but wanted to fix the problem first. So i google for the fix and i came to this forum and read all the stuff posted. I did all of that, cleaning Aperture thing, holding moderately battery and all that stuff but it did not work at all. so i put an extension hollow lens type for macro shot thought it would work, BUT it didnt so I think of myself what could be the reason. I thought it the Magic Lantern i installed so i put on a new new memory card without Magic Lantern but still the same problem. After much struggle i tried to end to process since it was not helping, i tried to dismantle the lens from the camera while still the extension tube was intact with the Sigma lens, while pulling out i looked thru the hollow lens and i saw something shiny like a wire with magnetic attach, so i thought this could be the faulty and i thought to myself even changing the contact chip of the lens. But that wire with magnetic thing attach struck me so put my finger into the lens where the wire was intact so i rub it and and push it inside with my forefinger and puch it inside again before it was hanging so i push it inside as well as rubbing it. After that i put back the lens with the camera and tried taking shots, i put it ope wide aperture thats the least i can go with the lens i.e.f3.5 and zoom all the way out, took a pic and thinking i had to on off the camera again since it always gives me that error after taking a pic, BUT VOILA, it WORKED, it didnt happen at all the error was gone so i thought this could be lucky shot, so i tried several pcs again and nothing happen anymore and i put the lens at each least zoom with wide open i,e. 18mm f3.5 and took pic again nothing happen no error again so i was amaze at it so tried several zoom and aperture setting and took a shot again and no error again, know that i am in Manual mode, so i tried AV,TV and nothing happen anymore no error anymore. I guess it was my lucky day. So i fix the problem and using the lens again. And i kept the lens as it has a macro capability so i like the lens even if its old.

M sharing my fixed as many of us are facing the issue and we found no fix for it. So i thought the group would like it. So tried it out and happy shooting with your old lens again.
Thats the wire with the magnetic strip. just rub it and push it down several times. Hope it would helped you all. Enjoy shooting.

I have same camera and lens as you, also getting the Err 01 message, must turn camera off and back on every time. Equipment about 2 years old, but this problem started about 3 months ago. Just about ready to give up -- any ideas?

I have a canon eos 450d and it wont let me take any pictures with any settings just comes up with: "err 01 Communication betweenThe camera and lens is
Faulty.
Clean the lens contacts. " i've tried cleaning the lense, and it didn't work! I'm an animator, and I really need to get it fixed soon as possible, any suggestions please?

I have a tamron 18-200mm , canon 450 eos and when i take a picture the camera send me an error "comunication between camera and lens is faulty,clean the lens contacts" , what can be the problem?

Thanks for all that. I have 450D, too, and sometimes use a Sigma fixed focus 400mm on my EOS10 and Rebel EOS500 with no probs so that's why I bought the Canon camera to replace them - I hoped! But, like others I am getting the message: Err 01
Communication between
The camera and lens is
Faulty.
Clean the lens contacts.

Cleaning didn't work and I used alcohol to clean the contacts. I had a theory about battery poke and maybe that's the real prob. Gonna try the pressure trick and then might see whether there is a way to extend the contact pins a fraction.