Son have an 08 Mazda 3 stuck in 2nd gear. We have read lots of tranny issues are caused by a bad TCM. Weve pulled battery box, air box and havent found TCM. Were there models that didnt have a TCM? This tranny doesnt even have the bolt holes on top for the TCM. Wonder if its even the original tranny. Any help is appreciated!

 

Transmission is controlled by the PCM.

 

If it is stuck as you claim in 2nd gear (however you determined that?) then it is a mechanical issue and you need to drop the pan and pull the valve body. But if my "guess" is correct you have a transmission that has never been serviced so start shopping for a transmission replacement (used) that will have at least a 6-12 month warranty?