Bizzare T5i Error 01 Situation

[dimsh2000]

I'm having a strange issue with a Canon T5i. It's the famous Err 01, but none of the solutions I've searched online work. I have the kit 18-55mm lens, 70-300 IS USM telephoto lens, and a 15-85 IS USM lens. All three lenses work just fine on other cameras I have (70D, T6i). However, on the T5i I'm getting the following:

1. 15-85 IS USM lens communicates, autofocus works intermittently, and Err 01 pops up half the time

2. 70-300 IS USM lens doesn't autofocus at all, no communication, no Err 01

3. 18-55 kit lens works fine with zero error

I've tried all the fixes I've seen online and the issue still persists. Cleaned the contacts on both the camera and lenses, played around with apeture settings, updated firmware, tried different sequences of turning the camera on and off and adjusting apetures. I've even replaced the contact pins on the camera to brand new ones and the error still persist in the same fashion.

Any idea what this could be? Any help would be greatly appreciated.

[shadowsports]

Greetings,

The Canon recommended solution is straight forward.

Clean the electrical contacts on the camera and lens.
Use a Canon lens.
If the instructions above do not solve the problem, please contact your nearest Canon Service Center

[ebiggs1]

"Cleaned the contacts on both the camera and lenses, played around with apeture settings, updated firmware, tried different sequences of turning the camera on and off and adjusting apetures. I've even replaced the contact pins on the camera to brand new ones and the error still persist in the same fashion."

Actually none of what you did is going to correct the problem and the last thing you did probably made sure of that. If resetting the camera back to defaults doesn't fix the issue you need to seek professional service.  However it may be beyond the cost of a used working T5i.  Cut your lose as you have a T6i to use which is working.

[Diego50]

Do you know what that error is called? scheduled obsolescence. That error has no solution and has nothing to do with the lens or contact cleaning. I have several lenses that work fine with other cameras but they don't work with my canon 5D Mark III with Err 01. Service is more expensive than a new camera.

[ebiggs1]

"Do you know what that error is called? scheduled obsolescence. That error has no solution and has nothing to do with the lens or contact cleaning."

That is pure nonsense! It is true that contact cleaning by the owner or FW updating rarely, if ever, helps but things do wear out or fail. It is just a fact of man made products. It is also unlikely the average person can successfully replace the contacts themselves.