Can the failure of the Transmission Control Module Cook the Transmission Fluid?

mazda
mazda5

#1

My transmission control module failed under warranty. The dealer admits that the TCM is under warranty and replaced it. However, while the dealer agrees that the transmission fluid needs to be replaced (because it’s burned), the dealer is taking the position that the failure of the TCM has nothing to do with the reason the ATF needs to be replaced. Car has had regular oil changes and no prior need for ATF replacement. There is no specific recommendation for the ATF replacement. Car is six years old and has approx. 40,000 miles.

I’ve looked on line and it looks to me generally like the TCM failure can affect the ATF (which makes sense because the TCM regulates the transmission, and the transmission is what burned up the ATF). But any specific thoughts or feedback would be helpful and much appreciated!

Thanks!


#2

Based on the advice from this board, I get the transmission fluid in both of my cars changed every 30K miles, regardless of what the manual says.

Personally, I think you’re splitting hairs here. You’re getting a new TCM for free. Transmission fluid wears over time. It didn’t just sudden get burnt the day the TCM went bad. I’d have already changed the fluid at this point were it my car just as regular maintenance.

Again, if it were me, I’d go get the transmission fluid changed on my dime, and move on with life.

Good luck.


#3

That is what the OP needs to do and find something else to fret about.


#4

It’s generally possible a faulty TCM could adversely affect the transmission fluid. But whether that happened in your case, hard to say. My guess: unlikely. If you posted the model year and engine and drivetrain options it’s possible someone here might be able to discover something more about this problem.


#5

This vehicle is 6 years old and a part was replaced under warranty . It is close to time to replace the transmission fluid anyway . It needs replaced so the person should just do it and move on.


#6

It is quite possible the defective TCM allowed the transmission to cook itself. The TCM sets the line pressure using the pressure regulator. If the line pressure is too low, clutches will slip excessively causing excessive heat in the fluid and burning. The clutch slippage will take life from the transmission as well as putting trash in the pan and torque converter.

I am sorry if this doesn’t help.