How do you tell if a CVT trans or valve body has failed?

[idosubaru]

CVT and valve body failures aren’t rare - so how do you tell the difference?  What’s the symptom differences?

[Numbchux]

The most common "valve body" failure that I've seen is the torque converter lockup solenoid, but the solenoids are not sold separately. On my mom's 2012 Impreza, it threw a code for the lockup solenoid, ohm'ed it out and it was either open or shorted (I don't remember which). I bought a chinese solenoid on Amazon, which worked for a few months. Then I got my hands on a used Valve body, the torque converter solenoid is identical to 2 of the shift solenoids, but the torque converter one is used almost constant 100% duty while driving, so I pulled the shift solenoids and used one in place of the failed converter solenoid, which worked great.

Of course, about a year later, the transmission started slipping, bucking and lurching, and being a salvaged oil burner, it now sits in my yard awaiting partout.

[idosubaru]

It seems valve body issues usually result in poor shifting but no noises. Whines and noises would be more indicative of CVT failure rather than valve body….that’s what comments seem to suggest but there’s a lot of i complete threads and comments so trying to get it right. 

[idosubaru]

And I do remember your thread and comments sourcing and fixing that solenoid. 

[Numbchux]

4 hours ago, idosubaru said:

It seems valve body issues usually result in poor shifting but no noises. Whines and noises would be more indicative of CVT failure rather than valve body….that’s what comments seem to suggest but there’s a lot of i complete threads and comments so trying to get it right. 

IIRC, there are 6-8 solenoids in the valve body assembly, so generally you'll throw a code and have a circuit to test. I do remember seeing a few that had other solenoids fail. But the lockup one was the most common.

Converter and transmission itself will generally lead to physical symptoms (sound, lurching, slipping, etc.).