Hi all

I have a 2010 Mazda 5 that's done over 130k miles. Last week the gearbox went into safe mode (seemed to shift into 3rd and stay there) and I pulled codes and it gave a TCM communication failure. I looked the cost of a new one, and decided instead to try a replacement from upfix.com. https://www.upfix.com/product/tcm-ma...epair-tcm-tcu/

It arrived and was easy to fit. While I tested things out, I attached to the firewall instead of reaching back on top of the gearbox. I drove it for a few blocks, and the AT light, but not the engine light, came on. I contacted upfix and they recommended changing the transmission fluid if had never been done (it hasn't) and then reseting the ECU/TCM. I've done both, but the AT light still comes on. My local garage has a better code reader and pulled the following codes.

P0732:FF Transmission Gear #2 incorrect ratio
P0734:FF Transmission Gear #4 incorrect ratio

The model numbers for the TCMs are slightly different and UpFix say they've programmed the replacement for my car.

Anyone have any advice? I've emailed UpFix for a replacement, under the assumption the unit they've sent is not programmed correctly. However, can those codes be indicative of another issue? How common is it for this car to have a failed gearbox at this age? We live in San Francisco, and the car gets quite a work out going up and down the hills and some of the roads here are in the middle of repair due to the bad weather.


My old device is on the bottom, the UpFix device on the top.

 

On rebuilt ECU/TCM/PCM etc, rarely do they go by the case number but when they do, they generally only test it for health and flash or do a pass-through which wipes the existing program and installs the last or most current programing.

From what you are posting you first need to get another unit from the supplier.

Then if you still have the problem the original diagnosis that the TCM was failed was incorrect.