Canon Xsi Error 99 ONLY in programs mode. Can shoot in Manual mode fine.

[CanonMaximus]

I have a Canon XSI and when trying to shoot in any of the program modes it will give error 99.

When shooting on the part of the dial that lets you set M / AV etc.....it will let you take pictures just fine , just no auto-focus.

Im thinking the problem is whatever controls the cameras ability to auto-focus, and when setting it to speed/mountain/automatic modes on the dial, I believe the error must be connected to ability to auto-focus but I might be wrong.

I have cleaned as much of the camera as I could. I tried using the end of a eraser to make sure contacts on the body was clean. I used new SD card. Updated firmware to 1.1.0. and reset settings to factory.

I dont mind using manual mode, but it would be nice to have auto-focus back. (yes I have tried other lens, and they all are not cooperating with auto-focus on that body.) The same lens work on my t5i just fine.

Does this sound like  software in the camera is bad? Something to do with inability to tell the lens to auto-focus? or something else?

[CanonMaximus]

UPDATE.....I was trying different settings out and found this to be key to what is wrong.

When using the viewfinder it gives error 99. On all settings you can do the live LCD screen mode it will take pictures just fine .

So I guess the real question is:

Since all modes that require using the viewfinder only to take a picture give error 99, what needs replacing to make this work again?

[deebatman316]

How are you trying to AF in live view. On older cameras a half press of the shutter button won't start AF. In order for AF to work in live view the "*" button must be pressed for AF to work in live view. These cameras also don't support on image sensor AF. The mirror will flip down and the dedicated viewfinder AF system will AF. Then the mirror will flip back after AF is complete. This will cause live view to go dark.

-Demetrius

EF 16-35mm F/2.8L III USM, EF 24-70mm F/2.8L II USM, EF 28-135mm F/3.5-5.6 IS USM (Retired), EF 50 F/1.8 STM, EF 85mm F/1.8 USM & EF 70-200mm F/2.8L IS III USM

EOS 40D (Retired) & 5D Mark IV

430EX III-RT, 470EX-AI & 600EX II-RT

[deebatman316]

Hello CanonMaximus welcome to the forums. The camera should AF in ALL modes as long as the AF/MF on the lens is set to AF. Will the camera throw an error code with the lens removed and will the camera take a picture without an error code. Also ALL EF/EF-S have an AF motor built into to the lens. NO EOS camera has EVER used a screwdrive AF motor in the camera body for AF. ALL EF/EF-S lenses use electronic communication between the lens and camera body. So the camera will take pictures in the CREATIVE ZONE (M,AV,TV,P) but not the BASIC ZONE (Full Auto Mode, Mountain, Sports etc). IT IS NOT RECOMMENDED to use an eraser to clean the lens contacts it is too abrasive and can remove the gold plating on the electronic contacts.

-Demetrius

EF 16-35mm F/2.8L III USM, EF 24-70mm F/2.8L II USM, EF 28-135mm F/3.5-5.6 IS USM (Retired), EF 50 F/1.8 STM, EF 85mm F/1.8 USM & EF 70-200mm F/2.8L IS III USM

EOS 40D (Retired) & 5D Mark IV

430EX III-RT, 470EX-AI & 600EX II-RT

[CanonMaximus]

Thanks for response.   I retried and yes it is doing auto focus in CREATIVE ZONE (M,AV,TV,P)
but when trying to do anything at all in BASIC ZONE thats when the err 99 shows up on screen.

Do you have any idea on why that would be?

[CanonMaximus]

Correction.

The camera will try to do autofocus if the LCD screen is being used, but trying to do photos at all using the viewfinder only gives the error 99..

[deebatman316]

Does the live view image blackout while AF is taking place or not. Some of these early cameras did support on image sensor AF but was very slow. So some of these cameras gave you the choice of "Quick AF" which uses the dedicated viewfinder AF system. This causes the mirror to flip down while AF is being performed then the mirror will flip backup once AF is complete. Will the camera throw a fault with the live view AF method set to "Quick AF Mode". Click Here for the manual. Set Custom Function 8 to option 1: Quick AF. 

-Demetrius

EF 16-35mm F/2.8L III USM, EF 24-70mm F/2.8L II USM, EF 28-135mm F/3.5-5.6 IS USM (Retired), EF 50 F/1.8 STM, EF 85mm F/1.8 USM & EF 70-200mm F/2.8L IS III USM

EOS 40D (Retired) & 5D Mark IV

430EX III-RT, 470EX-AI & 600EX II-RT

[CanonMaximus]

I tried something new.....   No matter what I set the dial too, as long as Im using the viewfinder it will auto focus. It will not even try to focus in LCD view.  If I have it set to Manual and take a shot with the viewfinder it will acutally take the photo. If i do that on the Full (basic mode) it will say error 99.

So this is very strange for sure.

[deebatman316]

A Custom Function must be set to allow AF in live view. How are you trying to AF in live view. Half pressing the shutter button won't work. You have to use the "*" button for AF to work in live view.

-Demetrius

EF 16-35mm F/2.8L III USM, EF 24-70mm F/2.8L II USM, EF 28-135mm F/3.5-5.6 IS USM (Retired), EF 50 F/1.8 STM, EF 85mm F/1.8 USM & EF 70-200mm F/2.8L IS III USM

EOS 40D (Retired) & 5D Mark IV

430EX III-RT, 470EX-AI & 600EX II-RT

[CanonMaximus · Accepted solution]

Thanks deebatman316   I did not realize that on this camera in live view it was the * button vs shutter 1/2 way down.

I think Ill just use it as it is now that I can autofocus in manual mode.    After trying that out, every once in a while I can take a few shots then roll over to the Green on the dial and take some photos that way thru the viewfinder then eventually it will give err 99, so I think the problem whatever is going on is intermittent.

Thanks everyone for the help!