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.

 

[PatDTN]

Is there a fuse I can pull?

Pat in Tennessee

 

[Clive]

... 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,

Our 2011 Tahoe (no issues) also has a hot 4WD selector - I assume it's the lamp that illuminates it, and therefore nothing untoward.

 

[PatDTN]

Thanks. I kinda thought it was just the light and I had never noticed before.

Pat in Tennessee

 

[MidwestMike]

Mine on my 2014 gets really hot too. I was just going to ask about that.

Everything works fine but the heat is almost scary. I did not think of the light, the best situation I was thinking of, without there being an issue, would be the heater ducts.

 

[PatDTN]

A friend told me it sounded like the Throttle Position Sensor was bad. Spoke to someone in Knoxville who advertises Tech 2 service and he agreed (for free) saving me the cost of having him scan. I put a new TPS in. Problem NOT fixed. I'm still trying to figure this out.

It seemed worse last night when I was running a bit faster than normal. I'm worried it's going to lock something up and leave me out of control in heavy traffic.

 

[TahoeLTZ2012]

Mine on my 2014 gets really hot too. I was just going to ask about that.

Everything works fine but the heat is almost scary. I did not think of the light, the best situation I was thinking of, without there being an issue, would be the heater ducts.

The shift knob on my 2012 also get quite warm, but everything function normal.

 

[PatDTN]

Update. I took the Tahoe to a highly recommended transmission shop nearby. He hooked up his scanning equipment and immediately saw there was an error for a sticking shift solenoid. Also he picked up that the shudder I've been feeling is a misfire that my OBD2 scan didn't show.

He dropped the pan and it looks like a metal shop in there. He said he's seen several of these. A bearing in the torque converter failed. Trans is toast. He could rebuild it in house but it's going to be cheaper to have him install a used trans with 117k miles on it that comes with an 18 month no miles warranty. He can get me back rolling Friday afternoon. He has to wait for the used trans to be shipped. With tax and labor it'll be $3300.00 or so. (I have an exact number but don't recall.)


Pat in Tennessee

 

[Tonyrodz]

Update. I took the Tahoe to a highly recommended transmission shop nearby. He hooked up his scanning equipment and immediately saw there was an error for a sticking shift solenoid. Also he picked up that the shudder I've been feeling is a misfire that my OBD2 scan didn't show.

He dropped the pan and it looks like a metal shop in there. He said he's seen several of these. A bearing in the torque converter failed. Trans is toast. He could rebuild it in house but it's going to be cheaper to have him install a used trans with 117k miles on it that comes with an 18 month no miles warranty. He can get me back rolling Friday afternoon. He has to wait for the used trans to be shipped. With tax and labor it'll be $3300.00 or so. (I have an exact number but don't recall.)


Pat in Tennessee

Damn! You can get a rebuild with all the updates for that price. Seems a little expensive for a used trans.

 

[PatDTN]

This is going to be serviced with new seals and such and installed in two days. And of course these are 6 speed trannys. I don't have the ability to shop around and put this off. While my truck is down I'm not earning any money.

 

[Tonyrodz]

This is going to be serviced with new seals and such and installed in two days. And of course these are 6 speed trannys. I don't have the ability to shop around and put this off. While my truck is down I'm not earning any money.

Sometimes you do what you gotta do.