Hot 4wd selector knob revs jumping around

[PatDTN]

My 2009 Tahoe has been acting funny for a couple of weeks. It seems to be shifting and locking/uunlocking the torque converter. It feels like I'm hitting bumps in the road. A friend who builds automatic transmissions for race cars said similar things happened to his earlier generation Tahoe and he found his transfer case was low on oil. I drained and refilled mine with fresh Dexron 6 but the symptoms continue.

Yesterday I decided to try shifting in and out of 4x4 to see if that had any effect. When I put my hand on the shift knob it was hot to the touch. Is that true for all Tahoes of this generation? I know it's lighted but this is the first time I felt this. Do I have a problem with the selector switch? The symptoms continued in or out of 4x4,

 

[swathdiver]

Get a Tech2 on it and see what's going on inside the circuitry.

 

[PatDTN]

Hm. No access to a tech 2.

Pat in Tennessee

 

[PatDTN]

I just googled Tech 2 and shopped on Amazon. They offer all kinds of other scanners but no Tech 2 shows up. I did just get an email from Harbor Freight touting this: https://www.harborfreight.com/zr13-obd2-code-reader-with-abssrsfixassist-63806.html and wonder if this is decent. Probably early to know but maybe someone has one?

 

[Doubeleive]

I just googled Tech 2 and shopped on Amazon. They offer all kinds of other scanners but no Tech 2 shows up. I did just get an email from Harbor Freight touting this: https://www.harborfreight.com/zr13-obd2-code-reader-with-abssrsfixassist-63806.html and wonder if this is decent. Probably early to know but maybe someone has one?

that would be a useful tool, but does not have the same capabilities as a tech2, you can find knockoff's on ebay but the real McCoy is pretty costly.

 

[PatDTN]

Is this the real thing? http://www.hobdii.com/wholesale/gm-...Z48kgkV8TPEy2o7YRXCTq6QGruqG-xFxoCqWcQAvD_BwE

 

[Doubeleive]

Is this the real thing? http://www.hobdii.com/wholesale/gm-...Z48kgkV8TPEy2o7YRXCTq6QGruqG-xFxoCqWcQAvD_BwE

nope that's a knock-off and it looks like that one wont even do truck's at all, there are some decent knock-offs on ebay for around the same price but they should do your Tahoe, read all the details.
a real one is usually over $1000 and even some of those can still be fake ones.

 

[swathdiver]

You can find them on Ali Express and even Ebay. There's a guy on ebay selling them from Arizona or thereabouts. Make sure to get the latest card, 33.004 and if GMT900, the Candi.

 

[PatDTN]

Thanks. These are going to be out of my price range.

Pat in Tennessee

 

[kbuskill]

You could try unplugging the switch and see what happens.