EOS 5D Mark IV err 01 24-70mm 2.8

[Pepper2004]

Hey Everyone, 

Every time I use my 24-70mm lens an "err 01" message appears on the screen of my Mark IV. I have had this lens and camera for 2 years (bought brand new) and this is the first time this has happened. I have cleaned the lens contacts numerous times but the error message wont go away. All of my other lenses work fine with my camera. Is there another solve or should I send it in for repair?

[NatalyaP · Accepted solution]

Greetings Pepper2004,

Error 01 can be caused by a few things since it relates to a communication issue between the lens and the camera body plus you were able to confirm that the lens will not auto focus. You have already cleaned the contacts on the back of the lens which is what we recommend. If the lens is still not working and still producing the error, then the next step is to send the lens in to our repair facility for service if you are using the EF 24-70mm f/2.8L II USM lens. In case you have the first version of the lens, the EF 24-70mm f/2.8L USM lens, then unfortunately, our facility is no longer repairing this lens model. An alternative option would be to participate in the Canon Upgrade Program.

The Canon Upgrade Program option allows you to replace your current lens with a new or refurbished Canon lens at a discounted price. If you would like to take part in the Canon Upgrade Program, please call our Sales Department at 1-866-443-8002 from Monday - Saturday between 9:00 am to 9:00 pm ET. Let them know you have been working with email technical support and the Canon Upgrade Program was offered. Be sure to have your serial number for your lens available at the time of your call.

For the second version of this lens, Canon U.S.A., Inc. has created a new online repair portal that allows you to set up service in a few simple steps. The repair portal gives you the ability to set up service for multiple pieces of equipment at once, and to receive a repair estimate in the majority of cases, depending on your model and issue. The portal also allows you to upload images or videos that will assist us in repairing your product. You can also select how you wish to be notified of the progress of your repair. The portal's service history section allows you to view all services that have been performed on any of your camera or video products since January 7, 2020.

Please follow the link below to access our online repair portal to arrange for service:

https://mycanon.usa.canon.com/signin

Instructions for Accessing and Using the Online Repair Portal.

You will need to access or create your My Canon Account.

If you already have a My Canon Account and your product is already registered, simply click on the “Get Repair Services” link on the left menu and follow the onscreen instructions to arrange for service for your product.

If you have a My Canon Account and your product is not registered, you must register your product first. Click on the “Get Repair Services” link on the left menu, then click on the “Register Product” link on the right. After your product is registered, click on the “Get Repair Service” link on the left menu and follow the onscreen instructions to arrange for service for your product.

If you do not have a My Canon Account, you will need to create one. After you create your account, click on the “Add Product” link to register your first product. After your product is registered, click on the “Get Repair Service” link on the left menu and follow the onscreen instructions to arrange for service for your product.

Once you have completed the repair request, you will have an opportunity to print a copy of the request for your records. This request form will also contain shipping instructions and an address label that you will attach to the outside of your shipping box when mailing your equipment for repair.

[HuyC]

I have a similar issue with my 24-70 2.8L mk1 lens on the 5D mk IV after updating the firmware from 1.0.2 to 1.4.  The lens was working perfectly fine before the firmware update.  It turned out to be potentially a bug in the firmware.  This also occurred on the 24-105 4.0L lens that I have as well.  

The issue is that the camera will not allow the lens to go below its maximum opening aperture.  If you let the lens stay at say, F2.8 for the 24-70 2.8L, then it will work fine.  If you decide to close the iris to F3.2, you will get the err01 screen.

I tried the lens on my 1DX mk2, and found no issue, at any aperture and any operating mode.

the 5D mk IV, with firmware 1.4, will work fine with, seemingly non L lenses, however.  

This is becoming extremely disappointing and frustrating for me.  If, I knew in advance, I would have not updated the firmware.  Canon team should put their heads together and figure out a fix for this.  We have perfectly good equipment that became handicapped after the firmware update.

[Stephen]

I'm not tech support, but there have been a lot of improvements from 2016-2023. Perhaps the camera can communicate with the lenses a little better now than it could then, and it can detect that the aperture is struggling to open up past a certain point? You may want to reach out to support so they can speak with you about this one-on-one. They're at 800-OK-CANON (800-652-2666), Monday through Saturday. 

[ebiggs1]

" I have cleaned the lens contacts numerous times but the error message wont go away."

You have found out what most of us long time, old timers, already know. Cleaning the contacts rarely to never helps. Plus it can make things much worse. The act of mounting and removing the lens is generally enough to keep the contacts working. I suspect the very few times it does help, is with folks that rarely change lenses. There’s a set of golden contacts on the lens rim and on the camera. They are spring loaded, you might look to see if they are not pushed in. They are fragile and one reason why cleaning can do more damage than good. The most likely cause for error 01 is a mechanical issue in your lens.

"All of my other lenses work fine with my camera."

Goes pretty far in telling you the problem is in the lens.

[Pepper2004]

Thank you everyone, lens is out for repair

[ebiggs1]

" I have cleaned the lens contacts numerous times but the error message wont go away." "... cleaned the contacts on the back of the lens which is what we recommend."

As you have seen by your experience and my own this rarely to never works or helps and there is the risk of damage to the contacts. I recommend to not do it since the gold layer is so very thin. The act of mounting and removing your lenses is enough to keep the contacts in good working order. Of course if something, or a contaminant, gets spilled or splashed on them cleaning is in order.