Canon's Error 99: the Man, the Myth

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The LensRentals Error 99 Process

This is based on Canon’s technical support suggestions, with a couple of additions we’ve made as we gained experience.

First, we pull a “tech support” reboot.

  1. Turn camera off.
  2. Remove battery.
  3. Replace battery.
  4. Turn camera on.
  5. Try a shot.

Sometimes that works. If not then a full reboot:

  1. Turn off the camera.
  2. Remove the lens, battery, date-time battery (see below), and CF card.
  3. Allow the camera to sit without power for approximately 20 minutes with the power switch “on”. Recharge the battery during this time. (Full disclosure here: somebody once suggested the 20 minutes and power switch on part, we want to top off the battery anyway, and we’ve generally got other stuff to do so we do it this way. Waiting 30 seconds and using a different, fully charged battery would probably be just as good, but this is what we do.)
  4. Turn off the camera, replace the backup battery, insert the fully charged battery, turn on the camera.
  5. Press the shutter button to check for Err99.
  6. If Err99 occurs, remove the battery, examine and clean the battery and camera connections. If at all possible, try a different battery.
  7. If Err99 still occurs, use the manual sensor cleaning function to raise the mirror and open the shutter. If the shutter does not completely open, it is the source of the problem. If a leaf is out of alignment, some people have reported using a soft brush to move the shutter leaf back into place. Personally, I’d send it in for service.
  8. If Err99 still occurs, the camera almost certainly needs service. You might try reinstalling firmware, but it’s unlikely to work.

If there’s no Err99 after the above, the next step is to check the storage system:

  1. Insert and format CF card, then press the shutter button as you would to take a picture.
  2. If Err99 try a different brand and size of card. If no Err99, the problem was the card and you should be done.
  3. If Err99 still occurs with a different card, the problem is with the camera’s card connections, and repair will be necessary.

Finally, check the lens:

  1. Turn the camera back off.
  2. Gently clean the contacts on both the lens and the camera (see Note #2 below)
  3. Remount the problem lens, set to manual focus, IS off, widest aperture and take a picture.
  4. If no Err99 with everything off, activate autofocus, then IS, then stop the aperture down, taking a picture to confirm no ERR 99 after each step.
  5. If Err99 occurs, try a different lens. If only one lens is a problem, that lens needs servicing. You’ll get better service results when you can be specific: i.e. “Err99 only when IS activated, etc.” in your service request.
  6. If Err99 occurs with more than one lens, and no other cause is apparent, the camera needs to head to Canon for repair.

Note #1: Some Err99 problems occur only with the camera in certain settings: i.e only in Av mode, or only in AI servo. In these cases, repair is almost certainly needed.

Note #2: I know first-hand that Canon Service Techs use the “gently rubbing a clean pencil eraser” technique of cleaning the electrical contacts. I also know that knowledgeable electronic engineers state this is a bad idea, that the friction could wear out the gold plating on the electronic connections, leading to corrosion. Radio Shack and other electronics stores sell electrical contact cleaning solution that can be used with a Q-tip or soft cloth to clean the contacts as an alternative. I’m still using the eraser; I figure if rubbing metal contacts across each other every time I change a lens isn’t wearing out the coating, the pencil eraser sure isn’t.


I know this has been an overly long and probably not-very-useful essay, but it’s a topic I really got into. I certainly will have made some omissions or mistakes in something this long and complex. I welcome corrections and suggestions from any of you with different experience in this area and plan on updating and upgrading this piece as I get more input.

112 Responses to “Canon's Error 99: the Man, the Myth”

amy said:

I have a cannon rebel with a 300 mm lens, the lens reads error 99 in cold weather and or to bright a light' I have taken to smacking the lens for the last 2 years and it works as long as I shut of the camera first..I use the small lens that came with the camra with no problems..my camera is now 4 years old but it still works great..the lens is the pproblem

Melvin said:

Had this issue 2-3yrs now on my 30D. Had to take out battery and rub battery contacts in a fast motion on my clothing to build up static, reinsert into camera just to get another 6 shots and then repeat it again.
SOLUTION: Drain camera battery dead as possible and put in fridge overnight. Take 2 car batteries and connect (+) posts together and do same with the (-) posts. Now run a loose wire off (-) post and another off the (+) post. Take the (-) wire from car battery and hold it or tape it on the (-) of your camera battery. Take wire coming off (+) post of car battery and rapidly tap it 7 times on the (+) leg off camera battery. Wait 30 seconds and repeat. WEAR GOGGLES!
Now insert camera battery into camera and kiss error99 goodbye! Good for another 2,000 cycles b4 error99 reappears.
Better yet...buy a new battery! Best...sell your Canon gear and buy a Nikon Camera because who needs this crap?

Rafael Casal said:

I am sending you this message from Alicante, Spain. I’ve read your great article from the beginning to the end very carefully. I’ve cleaned the lens contacts as well as those from the camera body.
I have a Canon EOS 1000D and my particular problem is that I can make photos with any of the 2 lens I have – both are original Canon lens - with no problem but when the camera turns off automatically or when I turn it off manually and turn it on again, I can make no further photos.

Nevertheless, I have found a solution to this problem. I set the auto power-off time to off and press the “DISP” button to save battery power. I can shoot, this way, all the photos I want with no problem at all. Once I have finished with the camera, I turn it off before keeping it.

I have to remove the battery and insert it again before turning the camera on the next time. And then shoot all the photos I want.

The thing is that I would like to know, in my case if possible, where the problem is. Is the battery the problem? Do I have to purchase a new battery? Or can it be an in-camera circuitry failure?

Rob said:

It looks like a lens problem rather than a camera body problem. I have a Canon 10D and a 30D. I have two identical Canon EF 28-80mm lenses. One of the lenses causes the Err99 message on both cameras except when shooting indoors on Auto with the camera implementing the pop-up flash. The other lens causes no error messages on either camera body. The display on the 10D says nothing about the problem. The display on the 30D tells me to turn the camera off and reinsert the battery. I do this but the very next shot brings up the ERR99 message again, so turning it off. reinserting the battery and then turning it on again is no solution. I have tried cleaning the contacts on the problem lens with a pencil eraser to no avail. The contacts have never had even a spec of dirt on them, but I still tried the eraser rub just to say I tried it. I'm still looking for a real solution, because turning the camera off and reinserting the battery hardly seems like a fix to a problem, especially when one lens causes the problem and the other one does not...on two different camera bodies.

Michelle said:

I get the error99 message with the Canon EFS 17-85mm lens in manual mode only; however no problems when using the Canon zoom 70-300mm. I inherited this camera and plan to use it as much as I can to learn the basics of photography and then I will likely look into a Nikon as I'm pretty astonished by the number of postings related to problems with Canon.

LensRentals Employee

Roger Cicala said:

Michelle, if you're seeing that many postings about Canon problems, you obviously haven't looked into the other brands very much. Canon is a bit better, although none are great when it comes to reliability. Nikon's far and away the worst for repairs and warranty work in the U. S., although it's very different in other countries.

Markus said:

I have a Canon EOS 1000D and have been experiencing this Error 99 problem for a couple of months now after a visit to the beach. I've done the usual tests, watched theYoutube video, worrried sand might be grinding in the lens mount (no) and thought i had isolated it to the CF card, since I found a work around that allowed me to shoot everytime the warning came up- eject the CF and reinsert immediately!

This allowed me at least a few more shots so long as I didn't manhandle the camera or turn it off. That seemed to trigger it again, pressure on the camera body or refocusing. But I've just had that the whole thing fail to turn on, which sounds like a battery problem. Trouble is the battery was reading "fully charged" at the time.

If the Err99 also gives a incorrect battery reading or a battery on it's way out reads as fully charged that could be it. I must admit I've had the battery for over 4 years- probably could do with a new one. But great article on the low voltage.

Tom said:

I have a mark11n 1ds. , I had this error I did the cleaning etc and thought it was fixed but now I have a 1 in the view finder and no images ? Could this be related or find i do ome thing like hit a wrong button ???

Michael said:

I have a Canon EOS 400D, that developed an error 99 with a few of my older lenses.
Turned out to be the first contact post on the body that the lens hits can get slightly bent and does not spring out quite as far as it used to, making intermittent contact.
I used isopropyl alcohol to lubricate the pin and levered it fully up with a sewing pin. I then used tiny needle-nose pliers to straighten it under a magnifying glass.

Fiddly and annoying but so far working fine without errors!

Chris said:

My 50D developed the ERR99 in the middle of a Powder Puff Football game the night before a kindergarten graduation shoot. I followed all the steps on here and had no luck. I did notice something strange though, I ONLY get issues w my Canon brand lenses. Even my L series lenses would not work BUT my Sigma EX HG 17-35 works perfectly... Any ideas before I send it to Canon?

Other Chris said:

My 1000D has had this problem for awhile, and it seems to be caused by the camera "forgetting" what number it is up to if it is turned off and back on. THe camera tries to assign existing image names from the last image taken, but if i delete that image it starts from the start of images taken the last time the camera had the battery removed ("reset"). Ie if I took 10 images last time, '11'-'20', then turned off/on, I get Err99. Off/on, then delete '20', camera will shoot once. Second shot, it will try and use '11' --> Err99. Off/on, delete some more images, more photos work. If I remove/replace battery, or open SD card door and close it again, the fault corrects itself until the next time the camera is turned off/on

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