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?

[deebatman316]

I believe your mirror box assembly is on its way out. The EOS 40D often would throw an error 99 code when the mirror box or mirror assembly failed. Error 99 means a fault has been detected by the camera. A lot of times the error 99 code meant expensive repairs. My old 40D through the error 99 code. Luckily it was still under warranty. The shutter and mirror box assembly were replaced. But the Rebel XSi is no longer serviced by Canon anymore.

-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]

deebatman316 Thanks for input and I agree its too old to repair when it totally goes. Take it easy.