I have a 2010 Mazda 3I. The transmission will be going along fine and then suddenly it seems to shift gears and the rpms rev up.
In my investigation, I am thinking it could be the TCM module.
If I order a new TCM module how do I know which one to order with out taking the other one off?
Also If I purchase a new one, Do I have to take it to the dealer to program it?

thanks for the input

Rick

 

Alway go directly to the supplier website to order parts. have your exact VIN year and month and country manufactured on hand.
DONT GUESS or take advise from anyone what the part number should be unless that person asked these question and you answered them.

I am not sure how you based you conclusion that the TCM has failing/failed. Guessing is likely to cost you more money replacing parts that are functionally ok. I guess the basic answer is when you scanned the TCM what did you find?

The first thing I always ask is
When was the last basic transmission service (miles) ?
What was it?
How many miles of service (current odometer reading)
Were there any problems of any sort during your ownership having to do with the transmission?
If so, what were they and what was the resolve?

 

No issues on the transmission
150000 miles on the car
Transmission has never been serviced


I ran the codes and received these. The codes on the transmission are PO720 and P0753. The engine code is P0171

 

*You will have a few issues.
The first thing is to drop the pan and have a look at the very dirty oil, varnish build up and collected material at the bottom of the pan and hopefully on the pan magnet.