Hello, I just bought a car for my daughter. The service engine soon light is one. So, I took it to Autozone and the codes point to the transmission.

I read and I know that the valve body in the transmission is a common failure. How do I know for sure that it is the valve body. I want to make sure before I spend $200+ on buying the part.

The vehicle has 132,000 miles on it. It shifts rough. More slamming or clunking into gears.

From your experience, where is the cheapest place you bought a valve body?

 

not me personally but probably a rebuilt one on ebay.

Rube?

 

Have you just tried a fluid and filter change first? I don't know of any way to determine if it's the valve body or not, but it was on mine. I bought a rebuilt one off ebay too. It solved my problem and isn't that difficult to replace. However, if your car has ABS, you have to take that assembly loose from the master cylinder in order to get enough clearance to get the frigging transmission pan off. It's just an extra step that they leave out of the instructions!

 

You can test the resistance of the individual solenoids in the valve body.

Just dug up a nice youtube video showing valve body solenoid testing with the valve body cover still on

https://www.youtube.com/watch?v=1tDmBlKn2jI

I don't doubt that it is difficult to test while in the car as stated in the video.Test both cold and hot. See video for acceptable resistance readings and for pin layout

Also consider input shaft nut loosening may be an issue here (search the net, it's out there)



Also be aware that even though the solenoids may read the correct resistance, they may be dysfunctional in other ways, so this is NOT a definitive test.